INT RODUCT ION
To improve safety and sustainability in today’s mobility society, it is necessary to bring together all the
relevant knowledge from across a broad range of disciplines, including the natural, social, and culturalsciences. Due to the continued but uneven worldwide growth of motorized transportation, disparities indaily mobility and access to life opportunities are widening between developed and developing countries and between metropolitan and local areas. This suggests that it is necessary to establish approaches
that take into account the diversity of mobility society. Therefore, we must establish a study of traffic andsafety sciences that is based on scientific evidence, rooted in area-specific situations, and searches forinterdisciplinary and practical knowledge. This book was developed as a preliminary textbook to address
such needs in advance.
The International Association of Traffic Safety Sciences (IATSS) celebrated its 40th anniversary in
2014, and publication of this book is a part of a commemorative project. IATSS, which is characterized
by its international and interdisciplinary nature, issued this book for domestic and overseas use as acompilation of the knowledge generated through its projects, especially those conducted over the past
10 years. The book has been published simultaneously in Japanese and English to promote education
and research in the field of traffic and safety sciences, and there is hope that the English version in particular will be useful in developing countries in Asia.
This book consists of two sections: Theory and Practice. The writing of the Theory section was led
by the editorial boards of the official IATSS journals, IATSS Review and IATSS Research, the latter ofwhich publishes English-language articles. Authors were selected from the fields of traffic engineering,urban engineering, electronics, information and communication engineering, mechanical engineering,
environmental studies, psychology, medicine, law, public administration, economics, and sustainability
science, and the essence of the knowledge in each of their individual fields is connected in an interdisciplinary manner. To develop the Practice section, 46 proposed research projects conducted at IATSS during the last 10 years were reviewed and 20 were ultimately selected for inclusion. Each project accurately
captured the current situations of domestic and overseas mobility societies and the practical wisdom
needed to improve each situation was outlined.
The content of this book is linked to the main theme of our 40th Anniversary Symposium, 2024
IATSS Designs for Mobility Society: Designing Ideal Mobility Society for 10 Years Down the Road. Keywords such as “diversity” and “transmodal” describing the mobility society after 10 years attracted attention at the symposium. “Design” abilities that combine vehicle technology, infrastructure, space, institutions, and culture as well as transmodal thinking are required to make the transportation system safer
and more comfortable for diverse users, to meet various social needs, and to transform travel demand—currently considered to be mostly a derived demand—into something that gives the joy and freedom ofmobility when using the system. We would be more than happy if this book, brought to publication after
much discussion, can serve as a guidepost to show the direction and vision of the next-generation
mobility society.

Special features and application of this book
This book, Traffic and Safety Sciences, which attempts to broadly address various issues surrounding the mobility society, is a compilation of the wisdom of experts in various academic fields about technologies and social systems that ensure traffic safety.
The Theory section is composed of 11 chapters, and in each, experts explain keywords
and phrases that are essential for study of the next-generation mobility society. Therefore, it
is not necessary to begin from the first chapter; the contents of each chapter are accessible
even if read out of order. The flow of this book is as follows.
In Chapters 1 and 2, experts in urban engineering provide knowledge needed to establish the mobility society by going over the roles of urban activities and traffic. In Chapter 3,
experts in environmental studies summarize the relationship between environmental issues
and traffic and provide insight into the establishment of eco-friendly low-carbon societies.
From Chapter 4, the focus of the book shifts toward traffic-related issues and the characteristics and solutions of traffic jams are discussed by experts in traffic engineering. In
Chapter 5, experts in information and communication engineering focus on the Intelligent
Transport System as an advance in transportation technology and discuss its history andfuture development. In Chapters 6 and 7, mechanical engineering experts explain safe vehicle technologies by examining the factors in traffic accidents. In Chapters 8 and 9, medical
professionals and psychologists explain the traffic-related psychology and behaviors of drivers and describe emergency medical care systems and accident prevention measures.
Traffic-related problems affecting the social system are addressed in Chapters 10 and
11. In Chapter 10, experts in law introduce traffic-related legal structures, criminal regulation, and risk management, while in Chapter 11, experts in economics describe sustainablegrowth while presenting conflicting concepts, such as balanced and unbalanced growth andregulation and deregulation. Lastly, under the Resilient mobility society heading, this book
discusses how a mobility society should be prepared for and how to recover quickly fromvarious disasters and socio-environmental changes.
In the Theory section, each chapter provides a listing of International Association of
Traffic and Safety Sciences (IATSS) projects related to the respective chapter’s contents. By
reading the Practice section after the Theory section, readers can see how the theories
address issues that pertain to specific areas.
It should be noted here that the aim of this book is not to exhaustively present professional opinions for each field. Rather, by going over each field in a cross-sectional manner,
this book intends to help readers learn about traffic and safety sciences from a multifaceted
perspective. Furthermore, the special interdisciplinary features of IATSS are strongly
emphasized in this book, and it would be a great pleasure to see readers discovering new
knowledge buried between chapters by reading each chapter and section freely.

Authors
Introduction
Kenji Doi

Professor, Department of Global Architecture, Graduate School of Engineering,Osaka University

Special features and application of this book
Akinori Morimoto
Professor, Faculty of Science and Engineering, Waseda University
TheoryChapter 1 Cities and transportation
Kenji Doi
Professor, Department of Global Architecture, Graduate School of Engineering,Osaka University

Chapter 2 Transportation and land use
Akinori Morimoto
Professor, Faculty of Science and Engineering, Waseda University
Chapter 3 Transportation and the environment
Tomohiro Ichinose
Professor, Faculty of Environment and Information Studies, Keio University
Chapter 4 Traffic engineering
Takashi Oguchi
Professor, Institute of Industrial Science, The University of Tokyo
Chapter 5 Intelligent Transport Systems
Takaaki Hasegawa Professor, Division of Mathematics, Electronics and Informatics, Graduate School of
Science and Engineering, Saitama University

Chapter 6 The image of automobile safety
Taro Sekine
Associate Professor, Department of Mechanical Engineering, College of Science andTechnology, Nihon University

Chapter 7 Technologies for safety improvement
Taro Sekine
Associate Professor, Department of Mechanical Engineering, College of Science andTechnology, Nihon University

Chapter 8 Traffic psychology
Kazumitsu Shinohara Professor, Graduate School of Human Sciences, Osaka University
Kazumi Renge
Professor, Department of Psychology, Faculty of Psychology, Tezukayama University
Chapter 9 Traffic safety and medicine
Kazuhiko Kibayashi Professor, Department of Legal Medicine, School of Medicine, Tokyo Women’s
Medical University

Takashi Moriya
Professor, Emergency Department, Saitama Medical Center, Jichi Medical University
Masaya Takahashi Senior Researcher, National Institute of Occupational Safety and Health, Japan
Chapter 10 Laws and policies pertaining to traffic safety
Makoto Saito
Professor, Graduate Schools for Law and Politics, The University of Tokyo
Hideaki Shiroyama Professor, Graduate Schools for Law and Politics, The University of Tokyo
Takeyoshi Imai
Professor, Hosei University Law School
Toru Ogino
President, National Police Academy, Japan
Chapter 11 Sustainable growth—An economic perspective
Kazuhiro Ohta
Professor, School of Commerce, Senshu University
Mariko Futamura
Associate Professor, Department of Economics, Tokyo Woman’s Christian University
Final thoughts Resilient mobility society
Yoshitsugu Hayashi Professor and Director, Education and Research Center for Sustainable
Co-Development, Graduate School of Environmental Studies, Nagoya University

Practice

Written by each project leader

ConTenTS

Introduction

5

Special features and application of this book6

Authors

7

TheoryChapter 1: Cities and transportation

12

Chapter 2: Transportation and land use

22

Chapter 3: Transportation and the environment

31

Chapter 4: Traffic engineering

40

Chapter 5: Intelligent Transport Systems

49

Chapter 6: The image of automobile safety

61

Chapter 7: Technologies for safety improvement

71

Chapter 8: Traffic psychology

80

Chapter 9: Traffic safety and medicine

89

Chapter 10: Laws and policies pertaining to traffic safety

100

Chapter 11: Sustainable growth—An economic perspective

116

Final thoughts: Resilient mobility society

125

Practice
A land utilization framework and transportation system for declining population

132

Quality of mobility required for super-aged cities

136

Urban development from parking lots considering inner-city parking density

140

Practical optimal signal control emphasizing pedestrian road crossing realities

144

Significant reduction of cycle length via a two-stage crossing system

148

A study on the practical deployment and promotion of safe and ecological roundabouts

152

A study on the role and limitations of motorcycles as a means of urban transport in Southeast Asia

156

Practical application of a public involvement-type system for planning and evaluating road traffic
safety measures

160

Identification of brain regions associated with the central and peripheral visual field and applications
for improving traffic safety

164

An educational program for better control of emotions while driving

168

A study on safety measures considering the psychological behavior characteristics of cyclists, fromadolescents to the elderly

172

Addressing issues associated with prehospital emergency transportation

176

Dissemination and promotion of screening for sleep disorders

180

Creating installation guidelines for tactile ground surface indicators (braille blocks) for thevisually impaired

184

Ensuring urban public transportation mobility for people with intellectual disabilities

188

A study on the level of service for local public transport to secure basic daily life

192

Traffic safety and traffic enforcement

196

Interdisciplinary research on the criminal charge of dangerous driving causing death or serious injury

200

Smoothly promoting urban development for transportation through collaboration between government
and local organizations

204

Realization of earthquake disaster crisis management and a society with safe and secure transportation

208

Chapter

1

Cities andtransportation
1.1

The dynamics of urbanization and the role of transportation

Cities change with the passage of time, moving from growth to decline. To make an analogy with human
life, cities pass from periods of childhood to adolescence (urbanization), young adulthood to middle age(suburbanization), and into old age (disurbanization). However, cities also expect a fourth phase notcomparable to human life, one of reurbanization.1) The form of urban transportation changes with thegrowth phase of the city, and the role of urban transportation changes as well according to the life cycleof the city as shown in Figure 1.
The role of transportation demanded in the urbanization phase is the carrying of large numbers ofpeople into the city, for example by railways. During suburbanization, the emphasis is on moving people
quickly over long distances. In the latter half of the suburbanization phase, the increasing developmentof low-density suburbs shifts the predominant modes of transportation toward private automobiles.
Later in the disurbanization phase, increased spread of low-density urban areas (urban sprawl) causes a
decline in public transportation created on the premise of mass transport, further increasing the dependence on automobiles. Many Japanese cities are still experiencing the effects of disurbanization (urban
decline), but some cities are trying to proceed to the reurbanization stage. The role of transportation inthis fourth stage is, in contrast to that during the suburbanization stage, connecting areas of agglomeration within the city at short distances and moderate speeds, and promoting interconnectedness between
these areas of agglomeration.
The heavily automobile-dependent United States has been often called a “suburban nation.”2) ,3)
However, the spread of road infrastructure and automobile use during the 20th century made it the“suburban era” for many countries worldwide. Those looking to escape from problems caused byincreased urban density due to increasing populations looked to suburbs as a kind of utopia that would
provide a wealthier countryside lifestyle, resulting in the mass production of largely uniform residential
and commercial suburban development all over the world. Artificially planned suburbs with decentralized and individualistic lifestyles were supported by freedom of movement for private car owners, andlater changed form into widespread sprawl development. This exacerbates the problem of automobile

Chapter 1: Cities and transportation｜13

Urbanization

Population growth andcongestion due to overcrowding• Provision of railways, etc.

Suburbanization

Population growth andurban expansion• Motorization• Long distances, high speeds

Disurbanization

Continuation of expansion anddecline• Motorization• Decline of public transportation

Reurbanization

Re-agglomeration of urban hubs
• Connected accessible
transportation• Short distances, low speeds

Figure 1. The urbanization process and the changing role of transportation

dependence, creating a negative synergistic effect between motorization and suburban sprawl.4)
The root of such urban and transportation problems is, in short, that our thinking regarding therole of transportation has halted at the suburbanization phase, considering that the goal of transportation must be “long distances, high speeds.” We must evolve our thinking to the reurbanization phase,where the goal is rather “short distances, low speeds.”

1.2

Mobility and accessibility

Mobility is generally defined as the ability to
move, and according to Ota 5) represents “theIndividuals

degree of freedom of general individual movement with no regard to specific destination.” Intransportation studies. Specifically, the word canalso be defined to mean the ease of reaching destinations and opportunities such as workplaces,
shopping, and medical services, or the ease withwhich one can make use of them. In recent years,
accessibility and usability have come to be a

ing
ell
Dw

y
vit

desired destinations.” The word “accessibility” isalso widely used in fields such as geography and(resources)ti
Ac

contrast, accessibility refers to “the ability to perform demanding activities through movement toAbil
re ity tso o u(m urc tilobe izilit s ey)

Place

Opportunity

Travel(service)(residence)
Ease
(acce

Freedomof choicesof reachssibility)Figure 2. The relation between mobility
and accessibility6)

14｜Theory

central concept in ideas in universal design.7)
Figure 2 shows the relationship between mobility and accessibility in a schematic form for a single
individual. Here, mobility is considered as the ability of an individual to make use of resources (time,money, external support and assistance, as well as environmental factors, etc.) through movement, andaccessibility as ease of reaching essential opportunities and services. The perspective of mobility captures the degree of human-centered freedom of choices, while that of accessibility captures the degree ofplace-based freedom as relating to the places that attract people. Our overall freedom of choices is determined by both mobility and accessibility.

1.3

Urban travel speed and safety

At the national level, emphasis should be placed on fast mobility to connect cities and hubs at high speedby the latest technologies, including a maglev Shinkansen and a logistics Shinkansen for the country’s
high-speed rail network. On the other hand, slow mobility for enjoying excursions and interactions at asafe and comfortable speed should be emphasized for personal and social reasons at the local level. Rigid
differentiation of travel speed according to location is required for achieving sustainable transportation
as well as increasing the attractiveness of cities.
In Japan, which is experiencing the problems of population decline and super-aging of society,large-scale shrinking of cities is required from the perspective of national land and urban management.
However, such severe constraints can also serve to foster creativity that can break through the impasseand lead to co-evolution of transportation, urban, and social developments. The development of “shrinking cities” to achieve sustainability and the development of “creative cities” to increase competitivenessare strategies that are two sides of the same coin, and the realization of both will require a reconfiguration of the bonds between the elements of people, knowledge, goods, services, money, and time. Mobility is the key to doing so. As mentioned in Section 1.2, mobility refers both to freedom of movement andability to make use of resources.
Building a mobility system for cities that are both sustainable and highly competitive will require a
multifaceted understanding of the value of mobility, along with the formation of a hierarchical network,
consisting of a fast mobility layer that connects cities and hubs at high speed and a slow mobility layer
within cities and hubs that promotes excursions and interactions at low to medium speeds. Slow mobility refers to means and forms of transportation at near-human speeds. But why is such distinction
between speeds necessary?
A negative aspect of motorization is its standardization of travel speed. Whether in towns, suburbs,
or between cities, most automobile drivers pursue speed. The desire for “long distances, high speeds”
mentioned in Section 1.1 is ever-present, whether one is inside or outside of urban areas.
The pursuit of speed regardless of places results in uniform expansion that impairs the hierarchy ofurban spaces. The result is longer daily trips to work and school, increased energy consumption fortransportation, increased production of CO2 and local environmental load, and even threats to life dueChapter 1: Cities and transportation｜15

Economy (efficiency)
Metropolitan
area
expansion

Hierarchicalstructureof networks

Total length ofroad and rail
networks

Distribution of population and employment
IncomegrowthDistribution of travel speed

Hierarchicalstructure ofurban spaces

Concentration anddispersion ofurban functions

Metropolitan
area
population

User benefit
Operator profits

Social (safety)

Speed between hubs

Value ofmobility

TDM, ITS
Smart choices

CO2 emissions
Environmental load

Speed within hubs

Ownership andusage ofautomobiles

Traffic fatalities
and injuries

Energy and the environment
Management of space,
speed, and demand

Figure 3. A causal relationship regarding the value of mobility and travel speed as the key factor

to increased risk of injury or death in a traffic accident (Fig. 3).
Figure 4 shows the relationship between urban population density, automobile travel speeds, andrates of road traffic deaths between 2008 and 2010 for 65 regional core cities with a population over
300,000 inhabitants in Japan. Bubble size in the figure represents the population of the city. From Fig. 4(a), one can clearly see that the rate of traffic fatalities increases with lowered urban density. Consideringthat this relationship may vary between cities due to differences in the development level and usage rates
of urban public transportation, we focused on only automobiles and analyzed the relationship between
population distribution and average automobile running speed for intra-city travel, as well as the relationship between average travel speed and traffic death rate. As the results in Figs. 4 (b) and (c) show, wefound causal relationships in which the more two-dimensionally dispersed a city was, the higher its
average automobile travel speed, and the higher the average travel speed, the higher the traffic death

6.0
5.0
4.0
3.0
2.0
1.0
0.0

0

5

10

15

DID population density (1000 people/ha)(a) Population density and road traffic death rate

50

7.0

45

6.0

Traffic fatalities per
100,000 population

Average travel speed (km/h)

Traffic fatalities per
100,000 population

7.0

40
35
30
25
20

0.4

0.6

0.8

1 .0

1.2

DID population ratio(DID population / city population)(b) Population distribution and average automobile
travel speed

5.0
4.0
3.0
2.0
1.0
0.0

20

30

40

Average travel speed (km/h)

50*DID: densely inhabited district(c) Average travel speed and road traffic death rate

Figure 4. Urban population density and distribution versus average automobile travel speeds and rates of road
trafﬁc deaths

16｜Theory

rate. 8) These results consider only the
relationship between density, speed, andsociety, the economy, and the environment, while keeping in mind the causal
relationships indicated by Figure 4.
One result of increasingly slower
movement speeds in urban areas and

Bus

50

Required time (minutes)

safety, so in the future there is a need toanalyze the effects of travel speed on

Walking60

BicycleAutomobile
Train

40
30
20
10

pursuit of the merits of slow mobility is0

the cycling revolution currently spreading in Europe. As shown in Figure 5, fortrips up to around 5 km bicycles have a

0

2

4

6

8

10

Distance traveled (km)Figure 5. Comparison of travel times by transportation mode for
intra-city travel

quicker travel speed than do automobiles and trains, and as is well known in Japan bicycles serve as an excellent, efficient and fast transportation mode within cities. The cycling revolution in London is famous for results such as its cycle superhighways and cycle hire (bike-sharing) scheme, but the social background and events leading up to thisrealization is rich in lessons. A series of socioeconomic factors such as soaring fuel prices starting
around 2002, the introduction of in-town road pricing in 2003, and subway and bus terrorist attacks in2005 are some of the influences that led people to use bicycles for their travel needs.

1.4

Aging and travel needs

As humans age they experience changes in physiological functions, reduced physical ability, reduced

In particular, the elderly placeless weight on the time and cost
aspects of travel, and more weight on

Abilitycognitive characteristics, and other changes in psychology and awareness that cause a decline in movement ability (Fig. 6). Figure 7 shows some of these mental changes that accompany increased age andresult in changes in travel needs.

Assumed previous
level of ability

travel that is safe, secure, and beneficial to health and the environment.
When this is displayed as a ternary
plot showing the positioning of vari-Assumed ability in a(super-) aged society• Changes in physiological function due to aging• Reduced physical ability• Decline in cognitive characteristics• Changes in psychology and awarenessous modes of transportation, the travelneeds in an aging society show a clear
shift up and to the right, representing
a shift toward demand for medium- to

0

20

40

60

80

Age

Figure 6. Changes in human ability accompanying age

per
che
a
nd
Fas
ter
a

0.2

25
–3
4
35 year–4s4y45 ears–54y
55 ear
s
–6
4y
ea
rs
65
+y
ea
rs
liv 65+ing yealo arsne ,0.0

Safety and security

Comfortable travel

Time and expense

Work and tasks

Health and the environment

35–44` 45–54
25–34 years

0.5
0.25

nity

65+
55–64

ma

0.4

Hu

0.6

bili
ty

tra
ve

l

0.8

Walking

0.5

Mo

0.25

1.0

th
eal
to h tial menefic ironben env
vel heTra and t

Weighting for quality of movement

Chapter 1: Cities and transportation｜17

Safe and secure travel

Current sense of values

0.25
0.50
Automobile

Publictransportation
Safety andtransportation capacity

10–15 years later

Figure 7. Changes in travel needs accompanying aging9), 10)

low-speed “slow mobility” that is located in the position between public transportation and privatetransportation. This is the position associated with transportation modes such as next-generation LRT
systems, low-speed electric community buses, community cycles, and other forms of shared personal
mobility.
Building the mobility system for a sustainable city will require a bold outlook on making thesechanges, and enhanced safety is the starting point of the change process. Doing so will require making
decisions on the priorities for and extensive management of speeds of road transportation. Efforts toachieve the harmonious coexistence of humans and automobiles through reducing speeds can be seenin European speed management programs such as the establishment of the “Zone 30” measure, which
establishes establish a 30 km/h (20 mph) zone. In recent years there have been increased efforts towardretaining comfortable space via improved road design that attempts to change driver behavior in waysthat reduce their running speed. There has also been a worldwide trend toward promoting “walkablecities,” which allow residents to walk to places necessary for daily life. These are some examples in whichhuman-centered prioritization has been established as the guiding principle for road and urban spacedesign.

1.5

Integrated design of cities and transportation

The term “integrated transportation” came into common use in the latter half of the 1990s. It goes without saying that a unified perspective is needed when developing transportation policy. The most important point is that one performs not an additive unification, but an integrated approach that combinesdiverse aspects into a whole. There are four levels in a desirable integrated transportation system:
1) Operational integration: integration of public transportation services, fare structures, and operation information
2) Strategy integration: integration of policy instruments for the infrastructure, management,

18｜Theory

information provision, and pricing between different transportation modes
3) Policy integration: integrated policies for transportation and land use; integrated policies between
transportation divisions and divisions for other areas such as the environment, health care,social welfare, education, and disaster prevention
4) Organizational integration: integration of the various organizations and institutions that are
responsible for transportation
Of the above, integrated transportation and urban design largely correspond to item 3), policy integration. In compact cities aiming for sustainability, as well as in transportation systems developed considering the needs of an aging society, addressing each of these in isolation will result in diminishedeffects. The expansion of cities seen in the twentieth century resulted from increased motorization androad development extended to far-reaching suburbs, in addition to population growth pressures. At aminimum, therefore, it is imperative to perform policy design of integrated transportation and urban
development.11), 12)
Figure 8 shows some of these integrated design concepts and procedures. The figure illustrates therelation of the four domains of city, infrastructure, mobility, and society; mobility is centrally locatedand is positioned as a system in which public transportation and personal mobility measures complement each other. “Road diets” refers to a method for creating space for pedestrians, bicycles and othermedium- to low-speed personal transportation modes by reducing the number and/or width of roadway
EconomyImprovement of overall efficiency
through allocating the righttransportation modes in the right places

Infrastructure
Mobility

Publictransportation Dynamic
linkage

TOD • Corridor

Districtcontinuation
program

Personal
mobility
measures

Road diet/renovation

Conversion to a compact
city through shrinking andre-agglomeration ofurban functions andspacesCompact and connected city

Environment

City

SafetyPriority and speed
management in roadtransportation

New infrastructure
ICT • Smart
Community

Community and new public

Community
infrastructure

Society

Design process
EquityTransition to a social systemstandardized on the elderlywith limited mobility

Figure 8. Integrated design of cities and transportation

Chapter 1: Cities and transportation｜19

lanes. This allows existing roads renovated with an emphasis on the usability of road spaces by a broader
range of users, and has already been implemented in many countries. In addition, transit-oriented development and corridor development are methods of supporting public and shared transportation from aland use aspect. Detailed discussions of these are presented in chapter 2.
As the design process loop in the figure shows, priority-based road space allocation and strict speed
management to secure traffic safety are the primary pursuit, and they result in the ability to render social
systems standardized on the elderly in which universal design can assist in providing increased accessibility. Also promoted is a conversion to compact cities in which urban functions and spaces are moreaggregated. When these conditions are met, regional public transportation becomes sustainable, and thestrategy of “allocating the right transportation modes in the right places” will lead to improved overall
efficiency. Implementing a mobility revolution will be impossible without holistic perspectives thatclearly prioritize management of speeds (slowness) and spaces (compactness), as well as time management that harnesses the opportunities and threats of external shocks and constraints, converting theseto revolutionary force. In Japan, there are continued trends for neglecting the global optimization intransportation policy; public transportation policy is still being discussed in isolation, and slow mobility
modes such as bicycles are positioned merely as local solutions without intermodal integration.
In a future of increasingly harsh economic and financial conditions, it will be difficult to improve
the quality of mobility in a super-aged society without meeting prerequisites of priority, slowness, andcompactness (PSC). Quality of mobility refers to social usability for users with diverse needs. Moving
beyond the physical, physiological, and ease-of-use levels of today’s “usable” mobility systems to a higher
level in which one psychologically wants to use the system will require a revolutionary process thatemphasizes PSC.
The view of linear growth that aims at an American- or European-style society has become lesseffective.13) Nevertheless, we find it difficult to abandon such concepts of growth in our pursuit of afuture mobility society. This is why our thinking on the role of transportation comes to a halt as
described at the beginning of this chapter. The development of a mobility society best suited to ourselves
will require consideration of not only technologies and systems, but also culture and ethos.

References
1) Klassen, L. H., J. A. Bonrdrez, and J. Volmuller. 1981. Transport and Reurbanisation. Gower.
2) Duany, A., E. Plater-Zyberk, and J. Speck. 2000. Suburban Nation: The rise of sprawl and the decline for the American Dream.
North Point Press.
3) Hall, P. 1996. Cities of Tomorrow. Blackwell Publish Ltd.
4) Hayashi, Y., R. Suparat, R. Mackett, K. Doi, Y. Tomita, N. Nakazawa, and H. Kato. “Urbanization, motorization and the environment nexus: An international comparative study of London, Tokyo and Bangkok.” Memoirs of the School of Engineering,
Nagoya Univ. Vol. 46, No. 1: 55–98.
5) Ota, K. 1988. Kotsu shisutemu keikaku [Transportation system plan]. Gijutsu shoin (in Japanese)
6) Doi, K., H. Nakanishi, M. Kii, and I. Sugiyama. 2006. “Examining policy implications of location efficiency as a key concept
in TOD implementation.” Journal of JSCE(D) Vol. 62, No. 2, 207–212. (in Japanese)7) Alshih, R., and D. Hensher. 2003. “The mobility and accessibility expectations of seniors in an aging population.” Transportation Research Part A Vol. 37 (A): 903–915.

20｜Theory

8) Doi, K. 2013. “Suro mobiritei” [Slow mobility]. International Journal of Automotive Engineering Vol. 67, No. 3, 24–31. (inJapanese)
9) Doi, K., T. Hasegawa, S. Kobayashi, I. Sugiyama, M. Mizohata. 2011. “A Study on ‘Quality of Mobility’ Demanded in Superaged Cities.” IATSS Review Vol. 35, No. 3: 38–49. (in Japanese)
10) Doi, K. 2011. “Komobiritei ga michibiku kotsu to toshi no kyohatten” [Co-mobility leading to transportation and social
developments] Japan Railway Engineer’s Association Vol. 54, No. 7: 4–6. (in Japanese)
11) Hayashi, Y., K. Doi, H. Kato, and International Association of Traffic and Safety Sciences, eds. 2009. Toshi no kuoritei sutokku:
Tochi riyo, ryokuchi, kotsu no togo senryaku [Quality Stock of Cities: Integrated strategy of land use, green space and transportation]. Kajima Institute Publishing. (in Japanese)
12) Doi, K., and M. Kii. 2012. “Looking at sustainable urban mobility through a cross-assessment model within the frameworkof land-use and transport integration.” IATSS Research Vol.35: 62–70.
13) Takeuchi, K. 2014. “The ideal form of transdisciplinary research as seen from the perspective of sustainability science, considering the future development of IATSS.” IATSS Research Vol.38.
Recommended Reading
1) Alonso, W. 1964. Location and Land Use. Cambridge MA: Harvard University Press.
2) Anas, A. 1982. Residential Location Markets and Urban Transportation: Economic Theory, Econometrics and Policy Analysis
with Discrete Choice Models. New York: Academic Press.
3) Banister, D. 2003. Transport Planning: In the UK, USA and Europe. Routledge.
4) Batty, M. 1994. “A chronicle of scientific planning: the Anglo-American modeling experience.” Journal of the American Planning Association 60: 7–16.
5) Berechman, J., and K. A. Small. 1988. “Modeling land use and transportation: an interpretive review for growth areas.” Environment and Planning A 20: 1283–1422.
6) Boarnet, M. G., and R. Crane. 2000. Travel by Design: The Influence of Urban Form on Travel. New York: Oxford University
Press.
7) Calthorpe, P. 1993. The Next American Metropolis. New York: Princeton Architectural Press.
8) Cervero, R. 1989. America’s Suburban Centers: The Land-use-Transportation Link. Unwin Hyman.
9) De la Barra, T. 1989. Integrated Transport and Land Use Modeling: Decision Chains and Hierarchies. Cambridge University
Press.
10) Dunham-Jones, E. 2011. Retrofitting Suburbia, Updated Edition: Urban Design Solutions for Redesigning Suburbs. Wiley.
11) Grant, J. 2006. Planning the Good Community: New Urbanism in Theory and Practice. London: Routledge.
12) Hall, P. 2002. Cities of Tomorrow. Wiley.
13) Hensher, D. A., K. J. Button, K. E. Haynes, and P. R. Stopher, eds. 2004. Handbook of Transport Geography and Spatial Systems. Elsevier.
14) Howard, E. 2010. To-morrow: A Peaceful Path to Real Reform. Cambridge University Press.
15) Iacono, M., D. Levinson, and A. El-Geneidy. 2008. “Models of transportation and land use change: a guide to the territory.”
Journal of Planning Literature 22 (4): 323–40.
16) Irwin, E. G. 2010. “New directions for urban economic models of land use change: incorporating spatial dynamics and heterogeneity.” Journal of Regional Science 50: 65–91.
17) Jacobs, J. 1992. The Death and Life of Great American Cities. Vintage.
18) Jenks, M., and N. Dempsey. 2005. Future Forms and Design for Sustainable Cities. Routledge.
19) Lynch, K. 1981. Good City Form. Cambridge MA: MIT Press.
20) Mees, P. 2009. Transport for Suburbia: Beyond the Automobile Age. Routledge.
21) Newman, P., and J. Kenworth. 1999. Sustainability and Cities: Overcoming Automobile Dependence. Island Press.
22) Simmonds, D., P. Waddell, and M. Wegener. 2013. “Equilibrium versus dynamics in urban modelling.” Environment andPlanning B: Planning and Design 40 (6): 1051–1070.
23) Speck, J. 2012. Walkable City: How Downtown Can Save America, One Step at a Time. Farrar, Straus and Giroux.
24) Vuchic, V. R. 2005. Urban Transit: Operations, Planning and Economics. Wiley.
25) Waddell, P. 2002. “UrbanSim: Modeling urban development for land use, transportation and environmental planning.” Journal of the American Planning Association 68: 297–314.
26) Walker, J. 2011. Human Transit: How Clearer Thinking about Public Transit Can Enrich Our Communities and Our Lives.
Island Press.

Chapter 1: Cities and transportation｜2127) Webster, F. V., and N. J. Paulley. 1990. “An international study on land-use and transport interaction.” Transport Reviews 10:
287–322.
28) Wegener, M. 1982. “Modeling urban decline: a multilevel economic-demographic model of the Dortmund region.” International Regional Science Review 7: 21–41.
29) Wegener, M. 1994. “Operational urban models: state of the art.” Journal of the American Planning Association 60: 17–29.
30) Wilson, A. G. 1997. “Land use/transport interaction models: past and future.” Journal of Transport Economics and Policy 32:
3–23.
Practical application projects for reference
A land utilization framework and transportation system for declining population: 132–135
Quality of mobility required for super-aged cities: 136–139

Chapter

2

Transportation andland use
2.1

The relationship between land use and transportation

Understanding the relationship between land use and transportation is extremely important for designing a prosperous and safe transportation society.1)
Land use and transportation are
Land-use planning
Transportation planning
Changes in traffic demandinterdependent, similar to a chicken-andUrban activities
Transportation activities(residential and industrial)(commuting, shopping)egg relation. Effective utilization of land
stimulates urban activities, and roads andChanges inChanges intransportation services
land useother transportation facilities are mainUrban facilities
Transportation facilities
tained so as to allow for new transporta(urban(road, rail)
development)
Changes in mobility
tion-related activity. Creating new roads
or expanding existing ones increases the
Figure 1. Relation between land use and traffic planning
attractiveness of the land they passthrough, promoting new urban facilities. When cities are growing slowly, it is easy for land utilizationand traffic planning to match pace. In times of rapid economic growth, however, demand for land use
accelerates and development of transportation facilities may be unable to keep up. Many cities experiencing a high degree of economic growth will therefore experience heavy congestion and other transportation problems.
How can the best balance be maintained between land use and transportation? Japan experienced aperiod of rapid motorization, a time during which it was impossible to keep up with demands for road
expansion and other transportation facility development, and therefore implemented policies to regulatetransportation demand itself. Such policies are called transportation demand management (TDM).
Examples of TDM include changing peak demand times and shifting demand to other modes of transportation, thereby enabling existing roads to be utilized to the fullest extent possible.
An even more fundamental approach is promoting optimal land use. For example, when transportation facilities are poor, the floor area ratio can be kept low and then the ratio can be increased according to the progress of transportation infrastructure development. Efforts can thus be made to achieve aChapter 2: Transportation and land use｜23

balance. Long-term sustainability should also be considered by altering the urban structure itself. For
example, transportation demands that are concentrated in downtown areas can be dispersed to city subcenters and core cities, thereby relieving congestion and promoting development of a more balanced city
overall. Such efforts in Tokyo and other large cities have been implemented as the construction of multipolar, distributed urban structures. The Third National Capital Region Development Plan (1976), forexample, recommends a more wide-area, multipolar distribution to correct Japan’s over-concentration
on Tokyo, and the follow-up Fourth Development Plan (1986) suggests prioritizing development ofbusiness core cities and secondary core cities with the goal of creating a more multi-zonal, multi-nuclear
urban structure.
There are differences in the emphasis placed on transportation problems such as congestion, noise,
and air pollution, depending on the region and era. Having entered the 21st century, the traffic problems
currently facing Japan, such as adapting to becoming a super-aged society and addressing global environmental issues, reflect increasingly long-term, wide-area considerations. However, even for such newproblems, considering land use and transportation planning over time can lead to finding solutions to avariety of transportation problems so as to meet the needs of the future.
What kind of urban structure should be aimed for, and by what method should such an urban
structure be developed? What kind of transportation facilities will be emphasized at that time? Howshould the remaining localized congestion be addressed? In this section, how developed countries are
addressing such issues is examined in order to learn about four keywords necessary in urban development for the next generation.

2.2

Compact cities

2.2.1 Why are compact cities needed?
The question of how to plan and aggregate urban areas that have expanded with the progress of motorization so that they can be converted to sustainable cities is a significant problem that faces mature societies. In Japan, which has entered an era of population decline, intelligent reduction in the scale of now
unneeded urban areas (“smart shrinking”) has become an urgent task. In the Second Report of the Panelon Infrastructure Development (2007), the following problems may arise when the structure of diffuse
cities is left unaddressed:• Difficulty in maintaining public transportation: It is difficult to ensure demand for public transportation in low-density cities.
• Problems with transportation in a super-aged society: There will be an increased number oftransportation-disadvantaged individuals who cannot operate automobiles.
• Increased environmental load: Excessive reliance on automobiles increases environmental load.
• Further decline of central urban areas: Promotion of suburban development causes a relative
decline in the attractiveness of urban areas within cities.

24｜Theory• Pressures on municipal finances: Increased maintenance costs of expanded urban areas.
Even in developing countries experiencing economic growth, inducing urban structures that areappropriate to periods of population increase is important for avoiding problems seen in developed
countries.
2.2.2 What is a compact city?
A compact city is one in which functions
required for daily life are aggregated in
the city center, and one with a maintainable city structure that retains an appropriate population density while remaining resident-friendly and environmentally

Green space

Green space

Attractive inner cities

Public transportation

Public transportation

friendly. In periods of population growth
Urban sprawl
there is a tendency for urban areas toGreen space expansion
encroach on green spaces, while in periFigure 2. Smart shrink
ods of population decline there is a tendency for green space to expand into urban areas. It is hoped that this will lead to an appropriate scale
reduction of the city itself. In particular, it is important that aggregation along public transportationlines strikes a proper balance between the use of automobiles and public transportation.
2.2.3 Proposal for network-type compact cities
Compact cities first attracted attention when they were proposed in the 1987 Brundtland Report as anurban model for sustainable development. Such cities aim at an environment that promotes public transportation and walking, and avoids over-reliance on privately owned automobiles. However, it isextremely difficult for cities to aggregate once they have expanded, and although local governments may
establish urban planning master plans as goals, achieving
such goals requires a longtime. Escape from low-density, automobile-oriented
urban structures cannot be
achieved without further
urban planning that features
public transportation as itscore. Here, we propose the“network-type compact city,”2)
based on transit-oriented
development (TOD), which is

Garden city theory (1898):
United Kingdom

Neighborhoods Theory(1924): USA
New Town policy of theUnited Kingdom (1950s–)“Shining city”
J. Jacobs(1961)

Edge City / New Town Development

Sustainable Community

1987 U.N. Brundtland Commission Reporton Sustainable Development
Calthorpe’s TOD(1980s)1973 Dantzig
compact city
(circular cities)

Compact City

Network-type compact city

Figure 3. A genealogy of network-type compact cities

Chapter 2: Transportation and land use｜25

described below.
A network-type compact city is one in which thevarious attractive features of the city are aggregated(compacted) in multiple areas that are connected (net-

Urban hubExpressway
Local traffic routeworked) by various modes of transportation, with afocus on highly convenient public transportation. Fig-

Urban hub

Hub

ure 4 shows the structure of such a city. In this context, the word “compact” does not necessarily mean
concentration at a single point but rather efficient
aggregation over multiple hubs. One feature of network-type compact cities is that they have disaster

Hub
Regional railway

Figure 4. A network-type compact city

resilience. Ensuring redundancy through the interconnection of multiple hubs of aggregation means that even if one part of the city is affected by a disaster,resilience of the city overall is increased because other areas can flexibly participate in recovery efforts.

2.3

Transit-oriented development (TOD)

2.3.1 The pros and cons of automobile-dependent city development
In times of rapidly increasing urban population, cities suffer from shortages of residential areas, whichleads to the development of many large-scale suburbs. Railway lines are often developed in large suburban cities, and further increase with the expansion of public transportation networks. Very different
from the development of regional cities, the development of suburbs is often done regardless of the convenience of public transportation, greatly increasing reliance on automobiles. Furthermore, commercial
development often occurs on the assumption of high automobile utilization, resulting in continued
development in areas along suburban bypass routes, spurring the decline of central urban areas.
The automobile is indeed a comfortable and convenient mode of transportation, but over-reliance
on automobiles detracts from other modes of transportation, and leads to the building of a society thatis unfriendly toward transportation-disadvantaged
residents who do not own an automobile. Learningfrom this, developed countries are turning their attention toward urban planning that focuses on public
transportation.
2.3.2 What is TOD?
TOD means urban development that is centered on
public transportation and avoids over-reliance on
automobiles. Its fundamental concepts were proposedin the 1980s by Calthorpe, but precursors to thisFigure 5. Conceptual diagram of TOD(P. Calthorpe)3)

26｜Theory

concept can be seen in Japan in the development ofareas around train stations, promoted by private railway companies since before World War II. Such development aimed at city planning in which commercial,industrial, and residential functions were situated in
an area within 600 m from train stations, allowing awalking-based lifestyle.4)
TOD is performed with an emphasis on threeimportant elements, called the three D’s: 5)
Figure 6. San Francisco (Fruitvale Transit Village)

Density: Maintenance of public transportation
requires ensuring a certain degree of population density. That degree will vary somewhat depending on regional characteristics, but in general planning should ensure that population density does
not go below 40 persons per hectare.
Diversity: It is important that commercial, medical, welfare, and other public functions be aggregated around train stations, so that basic life activities can be performed within walking distance.
Design: Good spatial design is vital to inducing land use. Attractive spaces have an effect on how
people choose where to live.
2.3.3 Urban area aggregation through implementation of TOD
Cities are connected with other cities
by rapid rail systems and other forms
Expressway
Road usageof high-speed public transportation,and the downtown areas of those cities are connected to their suburbs bylight rail transit (LRT) and bus rapid

Personal vehicle
BicycleNext-generation vehicles

els of public transportation service in

Fixed service area
Highways

TOD
Existing bus
LRT

Residential roads

transit (BRT) systems, thus providing
public transportation that is bothpunctual and fast. TOD is mainly
implemented along such public transportation routes.6) Providing high lev-

Railways

BRT

Public transport use
LRT, BRT, DRT

Expressway
High-speed trains

Variable service area

Figure 7. Urban space design implementing TOD

such areas over a long period of time and in a punctual manner promotes urban aggregation. In contrast, in suburban areas experiencing population decline, variable public transportation systems such as
demand response transit (DRT) are implemented.
Transportation-disadvantaged residents such as the elderly are encouraged to live in TOD areas,
while large families who most greatly benefit from the utility of automobiles are encouraged to raise
their children in the green-rich areas of the suburbs. Selection of residential areas according to lifestylethus allows for urban planning that best accommodates all generations.

Chapter 2: Transportation and land use｜27

2.4

Next-generation public transportation systems

2.4.1 Reconstruction of the hierarchical nature of urban transport
In many regional areas, trends toward excessive
reliance on automobiles have led to cities inwhich the only means of transport in and outof the city is by automobile. This has led to sig-

Hierarchical nature of urban transportation
High-speed movement

SubwaysWithin-city movement
Highways LRT, BRT
Main bus routes

nificant destruction of the traditional hierarchical nature of urban transport, such as
through-traffic encroaching into residential
areas and bus companies being forced to closeroutes. Development of a society that is environmentally friendly and compatible with asuper-aged society requires the urgent recon-

Inter-city movement

Expressways High-speed trains
Railways

Low-speed movement

Community buses
Residential roads Demand buses
Taxis

Automobiles

Inter-district
movement

Publictransportation

Figure 8. Hierarchical nature of urban transportation

struction of a transportation system that does not rely on automobiles alone.
Desirable next-generation transportation systems must strike a balance between automobiles andpublic transportation, through a hierarchical differentiation of transportation functions. Considering
automobile traffic, this hierarchy forms a pyramid with highways that maximize traffic functionality at
the top and highly accessible nearby residential roads at the bottom. Similarly, with regards to public
transportation the pyramid has rapid rail transit that allows high-speed movement between cities at the
top and community-level bus services that allow movement between districts at the bottom. As one
works toward the bottom of the pyramid, transportation speed decreases while flexibility of service
increases.
2.4.2 Functionality of next-generation public transportation systems
Revitalizing public transportation systems in cities in decline will require improving comfort and convenience. To that end, the following functions are required:
Punctuality: The system should not be affected by traffic congestion, such as through the use of
traffic lanes dedicated to public transportation.
Comfort: Transportation should be elderly-friendly, for example, by having little vibration andbeing barrier-free.
Environmentally friendly: The system should consume little energy, and minimize noise and pollutant emissions.
Attractiveness: Vehicles and pick-up locations should contribute to city planning by being suited
to the landscape.
The most important thing is that the system draws riders away from their automobiles and provides sufficient added value to alter land use along routes.

28｜Theory

2.4.3 LRT and BRT
Examples of public transportation systems that contain the above-mentioned functionality are nextgeneration LRT and BRT systems.
In contrast to heavy rail systems that provide transportation between cities, LRT systems provide
transportation within a city. In Japan, these often take the form of next-generation tram systems. They
are characterized by having improved functionality over older tram systems, being better integrated withother modes of transportation, and contributing to urban development by functioning as a comprehensive transportation system. The first LRT system was developed in Edmonton, Canada, in 1978. Since
then, LRT systems have been introduced in 111 cities (as of 2008) throughout the world.7)
BRT systems provide large-scale, rapid transport of passengers by bus. Unlike traditional bus
routes, these systems use dedicated traffic lanes to allow frequent and punctual service, which can insome situations improve transportation capacity through the use of articulated vehicles and allow forsmoother boarding at dedicated stops. Such systems are already in place in locations such as Ottawa(Canada), Curitiba (Brazil), and Bogota (Columbia).
A common feature between both systems is that they are introduced not as isolated methods oftransportation, but as one facet of a sustainable mobility system suited to next-generation cities. Such
attractive public transportation systems are expected to be effective at promoting better and more aggregated land use.

Figure 9. LRT in Houston

2.5

Figure 10. BRT in Curitiba

Large-scale development and transportation assessment

2.5.1 Traffic problems caused by large-scale development
In recent years, intensive land use and progress of the automobile society has brought about large-scale
development not only in cities but also in their suburbs. Traffic generated by new development isextremely heavy and has an effect over a wide area. The regions surrounding newly developed areas frequently already have a considerable amount of traffic demand, resulting in road congestion in someareas, so new developments have a high risk of further intensifying congestion, accidents, pollution, andother transportation-related problems. So what methods are there for easing chronic traffic congestion,

Chapter 2: Transportation and land use｜29

while still maintaining a balance between land use and transportation? This section describes one basic
method, traffic assessment for large-scale development.
2.5.2 What is a trafﬁc assessment?
Traffic impact assessments, or simply traffic assessments, are a method and system for assessing in
advance the effects of development plans on transportation in order to implement traffic policy from theperspective of harmonizing land use and transportation.
In a broad sense, traffic assessment is a macro-level approach for controlling land use patterns, density, and urban traffic master plans. In a more narrow sense, it can be applied as a micro-, district-levelapproach, which in Japan has been implemented for development exceeding a certain scale by the Ministry of Land, Infrastructure and Transport’s “Large-scale Development District-related Traffic Planning
Manual,” by the Ministry of Economy, Trade and Industry’s “Large-Scale Retail Stores Location Law,”
and by public safety commissions or traffic administrators’ “prior traffic measures”. Generally speaking,“transportation assessment” refers to the narrower definition.8)
2.5.3 Proper provision of parking lots for areas of large-scale development
When performing large-scale development, it is necessary to provide adequate parking that is commensurate with the traffic demand. For example, the Large-Scale Retail Stores Location Law requires that aperson who establishes large retail stores secure an adequate number of parking spaces.
The number of necessary parking spaces is determined by using an equation that takes the numberof customers, peak ratio, car ownership ratio, parking lot usage time, and other factors as parameters. It
is important to verify at the development assessment stage that an appropriate number of parking spaces
will be available.
X =A×S×B×C×E
D

A: Number of daily customers by store floor space (persons/1000 m2)
S: Store floor space (1000 m2) B: Peak ratio (%)
C: Car ownership ratio (%)
D: Average number of car passengers (persons)
E: Average parking time coefficient

2.5.4 Trafﬁc simulations for large-scale development
It is extremely important in traffic assessment to grasp traffic conditions quantitatively and in detail.
Innovations in information technology since the1990s have resulted in dramatic improvements tocomputer processing capabilities, allowing
detailed, second-scale reproduction of traffic
conditions and visual representations as animations, including signal controls, traffic lane construction, and other aspects. As result, many traffic simulators have been developed andpractically implemented both in Japan (tiss-NET,

Figure 11. Traffic simulation screen

30｜Theory

AVENUE, TRAFFICSS, VISITOK, etc.)
and overseas (NETSIM, Pramics,
WATSim, etc.).
Developing traffic simulations
requires substantial time and effort, so
application conditions need to be pub-

Table 1. Conditions of the traffic simulations in Tochigi Prefecture
Peak arriving vehicles
200–600 vehicles (100vehicles per direction)
600 or more vehicles

Relation between lot shape and traffic
No risk of congestion
Risk of congestion
Not needed

NeededNeededlicly documented. Consideration of traffic simulations from early stages allows those wishing to open
stores to apply them to site selection. Table 1 shows the implementation conditions for a traffic simulation performed in Tochigi prefecture.
From these results, merchants, road managers, and traffic control personnel can consider the effectsof congestion reduction policies before the establishment of large-scale stores. Note that there are many
significant effects of large-scale development, and in situations where mitigation measures are difficult
through transportation facility development, reconsideration of site selection for large-scale development may become necessary.9)

References
1) Sugiyama, Masahiro, Sotaro Kunihisa, Mitsuyuki Asano, and Hirohito Kuse, eds. 2003. Asu no toshi kotsu seisaku [TheFuture of Urban Transport Policy]. Seibundo Publishing. (in Japanese)2) Morimoto, A. 2012. “A preliminary proposal for urban and transportation planning in response to the Great East Japan
Earthquake.” IATSS Research Vol. 36, No. 1: 20–23.
3) Calthorpe, Peter. 1993. The Next American Metropolis: Ecology, Community, and the American Dream. Princeton Architectural Press.
4) Transit Cooperative Research Program. 2004. TCRP Report 102, Transit-Oriented Development in the United States: Experiences, Challenges, and Prospects. Transportation Research Board.
5) Developing Around Transit: Strategies and Solutions That Work. ULI (the Urban Land Institute). 2004.
6) Hayashi, Yoshitsugu, Kenji Doi, Hirokazu Kato, and International Association of Traffic and Safety Sciences, eds. 2009. Toshi
no kuoritei sutokku: Tochi riyo, ryokuchi, kotsu no togo senryaku [Quality Stock of Cities: Integrated strategy of land use,green space and transportation]. Kajima Institute Publishing. (in Japanese)
7) “Special Supplement: Challenges and Visions for Implementing Light Rail Transit in Japan.” IATSS Review Vol. 34, No. 2.
2009. (in Japanese)
8) Kotsu asesumento ni kansuru chosa hokoku sho [Investigation Research Report on Transportation Assessment]. International
Association of Traffic and Safety Sciences. March 2001. (in Japanese)
9) Seki, Tatsuya, and Akinori Morimoto. 2010. “Daikibokaihatsu ni okeru kotsu asesumento no seiri to kongo no tenbo” [AReview of Traffic Impact Assessment in Japan]. Journal of JSCE(D) Vol. 66, No. 2: 255–268. (in Japanese)
Recommended Reading
1) Randall, Thomas, ed. 2003. Sustainable Urban Design: An Environmental Approach. Spon Press.
2) Jenks, Mike, Elizabeth Burton, and Katie Williams, eds. 1996. The Compact City: A Sustainable Urban Form? Taylor &Francis.
3) Site Impact Traffic Assessment: Problems and Solutions, Proceedings of the Conference, Chicago. The American Society of Civil
Engineering. 1992.
4) Transportation Impact Analyses for Site Development. Institute of Transportation Engineers. 2006.
Practical application projects for reference
A land utilization framework and transportation system for declining population: 132–135
Urban development from parking lots considering inner-city parking density: 140–143

Chapter

3

Transportation and theenvironment
3.1

Transportation and environmental issues

The 21st century has been called the “century of the environment,” and the relationship between transportation and the environment has greatly changed due to changes in modes of transportation and theenvironmental issues being focused upon. For example, in “Kotsu to Kankyo,”1) the Japanese translationof the 1988 OECD report “Transport and the Environment,”2) issues such as air pollution and noise areraised as examples of the effects of land transportation on the environment, but there is no mention of
global warming. The Framework Convention on Climate Change was only adopted at the 1992 Earth
Summit in Rio de Janeiro, and was finally put into force in 1994. At that time, the Convention on Biological Diversity was hardly recognized, both in Japan and across the world.
In the Comparative Study on Urban Transport and the Environment (CUTE), sponsored by theSpecial Interest Group on Transport and Environment at the World Conference on Transport ResearchSociety between 2001 and 2004, the focus of research was on environmental issues such as automobile
emissions and noise, in particular localized air pollution and greenhouse gases.3) This attests to the fact
that, upon entering the 21st century, global warming was finally gaining widespread attention.
However, the environmental effects of transportation cover quite a wide range. The focus is mostcommonly placed upon automobile-related air pollution and global warming, as in the case in CUTE, tothe extent that there is very little discussion regarding the relationship between the environment andother forms of transportation. Table 1 shows a listing of the environmental effects of major forms oftransportation, and is based on the table in the above-mentioned OECD report,2) with extensive additions and revisions by the author.
Regarding the effects on air pollution, automobiles are most commonly examined due to the scaleof their effects, but marine and other water-based transportation, rail transportation, and air transportation also exhibit a variety of effects. For example, in 2011 air transportation accounted for only 3.9% ofcarbon emissions for the transportation sector as a whole, but the demand for international aviation services is expected to grow rapidly and reach a sixfold increase by 20504) compared to the demand in 2010.
Before global warming took center stage, acid rain was a central topic, particularly in Europe. In recent

32｜Theory

Table 1. The effects of transportation on the environment (Table 1 from reference 2, with additions by the author)
Transportation
mode

Air

Maritime
CO2 emissions
transportationand inland
Air pollution
waterwaysRailtransportation

Carbon dioxide
emissions
Air pollution

Carbon dioxide
emissionsRoadtransportationAirtransportation

Air pollution (Inparticular, fueladditives such as
CO, HC, NOx, dust,
and lead)

Carbon dioxide
emissions
Air pollution

Land

Port facility
construction

Water (including
groundwater)

Construction ofrelated facilities,
including roads
Terrainmodification due
to roadconstruction
Procurement ofmaterials for road
construction

Airport facility
construction

Noise, vibration

Facilities, shipdisposal

Division ofunderground water Facilities andvehicle disposal
veins by tunnel
construction, etc.

Division ofunderground water
veins by tunnels,
Facilities andetc.
vehicle disposal,
waste oil
Development ofwater regions andchanges in water Battery disposal
system due to road (especially forhybrid and electric
construction
vehicles)Surface andgroundwatercontamination

Development ofwater regions due
to airport
construction

Ecological impact
Expansion ofinvasive species
by ballast waterPort facility
construction

Drilling and
Canal construction dredging rivers
and coasts

Railway andstationconstruction

Waste

Noise around theportLandscape

Loss of natural
coast, rivers

Endocrine
Landscapes with
disruption of
ships
organisms by painton ships
Disruption ofnatural andtraditionallandscapes

Habitat
Noise andfragmentation
vibration nearstations and along
Creation of a new
Collision accidents
railwayslandscaperesources(vehicles, bridges)

Automobile noiseand vibrations incities and along
major routes

Noise and shock
Disposal of aircraft waves near
airports

Habitatfragmentation
Disruption ofCollision accidents
natural andtraditional
Disruption due tolandscapes
pollutants
Contamination byanti-freeze agents
Light pollution bystreetlights

Creation of newlandscaperesources (bridges,
etc.)

Habitat destruction
Loss of naturalby airport
landscapes
development
Collisions withairplanes (mainly
birds)

Landscapes withairplaneyears, however, fine particulate matter with particles of diameter 2.5 μm or less (PM 2.5) is the primarycause of pollution in China and other developing nations.
The impact of transportation on the environment can be roughly divided into the effects due toroads and other infrastructure, and the effects due to automobiles and other transportation vehicles.
Transportation vehicles have greater impact in the atmosphere, but on the ground the primary impact isdue to infrastructure maintenance. This is divided into facilities such as ports, stations, and airports, andthe construction of linear routes such as canals, railways, and roads. Transportation routes must be continuous, and therefore necessarily separate natural environments and land use. Furthermore the scale offacilities such as airports is quite large, and this can have a significant impact on both natural environments and land use.
Transportation infrastructure is also the cause of much of the impact on water regions. The effectsof transportation on rivers and coastal areas have been pointed out in many past studies, most of which

Chapter 3: Transportation and the environment｜33

show a degradation of water quality due to development. Disruption of underground water veins due tounderground transportation via tunnels has also been shown to reduce and pollute underground water,
and to increase maintenance costs for drainage of water. There are also many cases where transportation
machinery leads to the pollution of water areas. Regarding ground transportation, the various chemical
products emitted by automobiles are concentrated along roads, and then dispersed into the surrounding
environment.
Large amounts of waste are produced when transportation-related infrastructure is abandoned or
renewed, and when the vehicles that utilize such infrastructure exceed their serviceable lifetimes, these
too must be treated as waste. In Japan, the Act for Automobile Recycling mandates that such vehicles berecycled, and recycling rates have reached approximately 99%.5) However, there is a possibility that the
rapid spread of hybrid vehicles, and the expected increased popularity of electric automobiles and nextgeneration environmentally friendly vehicles, will result in increased battery disposal, so the cost ofrecycling may increase.
Regarding noise, with the exception of marine transportation, there has been extensive research,
and a variety of measures have been attempted. Infrastructure maintenance exceeding a certain scale issubject to the Environmental Impact Assessment Law, and must meet certain legally determined standards. There has also been continued development for the suppression of noise and vibration due totransportation vehicles. Japan is currently developing a maglev train line and continues to expand
Haneda Airport, so new issues related to noise and vibration are likely to develop.
There have been few investigations into the effects of transportation on organisms, despite various
indications for doing so from the fields of biology and ecology. The largest impacts are habitat fragmentation and loss. As I explain in more detail below, the most frequently discussed measures are environmental mitigation and eco-roads. Various other effects are also seen, but two particular features ofmarine and other water-based transportation are extended distribution ranges of invasive species due toballast water, and endocrine disruption due to the paint used on ships. In the case of air transportation,
collisions between airplanes and birds are the major problem, which can also pose danger to human
lives.
One final impact is that on landscapes. The OECD report2) makes no mention of this point. Nonetheless, transportation-related infrastructure has a significant impact both on natural scenery and on
traditional and historic views that have been cultivated over many years.6) An interesting feature of thisissue, however, is that transportation machinery and infrastructure itself can become a scenic resource.
For example, one does not need a particular interest in railways to feel a sense of beauty when viewing aphotograph of a train crossing over a bridge that straddles a valley, and there are many instances wheretransportation infrastructure itself becomes a popular landscape spot, such as in the cases of the Yokohama Bay Bridge or the Akashi Kaikyo Bridge.

34｜Theory

3.2

Road greening and parkways

The environment and transportation infrastructure have developed in close association with each other.
For example Hirasawa7) describes how rows of trees were planted as far back as the early 7th century as aform of road greening in Japan, and how records from the 8th century state that the planting of thesetrees was mandated, as they provided traveling farmers with shade in which to rest and fruit to eat when
they were hungry. The Tokugawa Shogunate later developed tree-lined roads throughout Japan, and the
beginning of using stands of cherry trees for recreation was in the first half of the 18th century, when
Tokugawa Yoshimune opened orchards in the area around Edo.7) This can be viewed as the birth of Japanese-style open space planning.
The development of green space in the West received a major boost when Friedrich Franz Leopold
III, the Lord of Dessau, became strongly influenced by the landscape gardens of England, and thereby
renovated Wörlitz Castle into a landscape garden between 1768 and 1770. Landscaping was thereafter
promoted throughout the territory, forming the birth of open space planning in Europe. It was theUnited States that first established a park system coupled with road planning.
The need for parks and green spaces was strongly felt as a result of the expansion of American cities
in the early 19th century. New York’s Central Park was designed by Frederick Law Olmsted in 1873. This
was the first large-scale urban park to be built in the United States. At around the same time (1868) the
first parkway—a road developed along with a park—was built in Brooklyn.8) The definition of “parkway”
remains unclear, and already has diverged from its original meaning, but later developments in Boston,Minneapolis, and Kansas City featured a variety of axial roadways combined with green spaces, also
called parkways.8) In late 19th-century Boston, the development of parkways and green spaces was sublimated into open space planning in the form of a park system.9) This occurred before automobile usage
was widespread, in a time where roads were generally used for horse-drawn carriages.
After automobile usage rapidly spread in the early 20th century, parkways appeared as roads designated for automobile use only. This was done toallow automobiles to travel at higher speeds thanhorse-drawn carriages, as exemplified by the development of the Long Rheinland State Parkway in the
1930s.8) Parkways later began to spread throughout
the world in various forms, such as national parkroads and pay roads through scenic areas. American-style parkways were soon introduced into
Japan, starting with the Shonan Coast Park Road
(now part of National Highway Route 134), whichbegan construction in 1931 and was completed in
1936, as the first parkway in Japan10) (Fig. 1).

Figure 1. Current National Highway Route 134(taken by the author in June 2014, near the Hamamiyama Kobanmaeintersection)

Chapter 3: Transportation and the environment｜35

3.3

Ecological mitigation and eco-roads

The development of railway and automotive technologies has realized high-speed movement, and automobiles in particular make possible high mobility that allows any-time, anywhere movement. The highdensity development of supporting railways and roads has arisen alongside the development of highspeed ground transportation. Following World War II in particular, global political stability andeconomic development caused transportation infrastructure development to rapidly expand, and thisbegan to have a large impact on the natural environment. In 1969 the United States enacted its National
Environmental Policy Act and institutionalized various forms of environmental impact assessment inorder to avoid, to the extent possible, the effects of various kinds of development on the natural environment. While falling far behind the countries of the West, in 1997 Japan too enacted its Environmental
Impact Assessment Law. Development exceeding a certain scale is now required to undergo environmental assessment, the possible effects of business on natural environments are investigated, and furthermore follow-up surveys after project completion are also required. However, the institutionalizationof mandatory environmental impact mitigation has gone even further in Western countries such as theUnited States and Germany. Environmental mitigation (often simply called “mitigation”) is a method for
ensuring “no net loss” of wildlife habitats before and after development and other such activities through(1) avoiding effects by refraining from certain activities, (2) reducing effects by limiting certain activities, (3) correcting effects through repair, rehabilitation, and restoration, and (4) reducing or eliminating
long-term negative effects through protection measures and management, supplying alternate resources,
and making up for negative effects through replacement, with steps taken preferentially in that order.11)
Figure 2 shows a railway near Frankfurt, Germany, in which quadruple tracks are being planned to meetthe increased demands of recent years. Such artificially created railway embankments are a habitat forthe sand lizard (Lacerta agilis), an endangered species in Germany, so this rail construction is likely tohave a significant impact. Measures to develop alternative living spaces in the surrounding areas are
therefore planned prior to construction so that the lizard populations can be maintained. The abovementioned procedures for quantifying thetotal amount and quality of organism habitats
are operated in the United States using a system called mitigation banking,12) which had
begun to be utilized before the greenhouse gas
emissions trading system was established.
Environmental mitigation is involved in
all forms of development not just transportation infrastructure, but continuous linear
developments such as roads and railways arecharacterized by the potential to divide organism habitats. This results in loss of habitat, as
well as animal deaths due to vehicle collisions

Figure 2. Railway embankments are an important habitat for
the endangered sand lizard (Lacerta agilis)(taken by the author in July 2014, in Wetterau, Hessen, Germany)

36｜Theory

while trying to cross the road, disruption of life-cycles for amphibians and other animals that musttravel between forests and waters, and reduced genetic diversity due to reduced chances for mating
between adjacent populations. Therefore, there have been efforts toward reducing to the extent possible
such effects on organisms, particularly with regard to animal movement, and such attempts are collectively referred to as “eco-roads.” As in the case of environmental assessment, various cases have alreadybeen accumulated in the West and have begun to be introduced to Japan, starting with the 11th Fiveyear Road Development Plan, which called for the increased development of eco-roads.13) A wide varietyof specific measures have been implemented, to protect not only fauna, but flora as well. The development of eco-roads is often positioned in the above-described environmental mitigation procedures in
the West. Various cases have been seen in Japan too, but in most cases road construction is decided first,
with tunnels and bridges for animals prescribed as symptomatic treatments, so in many cases it becomes
questionable as to whether the effects are sufficient to allow calling such projects “eco-roads.” A recent
study14) indicated that somewhere between 89 and 340 million birds die in America each year due tocollisions with automobiles, so further measures will likely be needed in the future.

3.4

Transportation and invasive species

I began by discussing global warming, but there is also a need to confront declines in biodiversity as a
global environmental issue of the 21st century. Alongside the Framework Convention on Climate
Change, the Earth Summit held in Rio de Janeiro in 1992 adopted the Convention on Biological Diversity, which entered into force in 1993. While previously having less recognition than global warming
issues, the Convention on Biological Diversity’s tenth meeting of the Conference of the Parties (alsoknown as COP10) held in Aichi Prefecture in 2010 suddenly brought biological diversity to the spotlightin Japan. Japan’s National Biodiversity Strategy 15) gives detailed information regarding factors thatthreaten biodiversity, but another issue related to its relationship with transportation is the transfer ofinvasive species. One famous example is the white clover (Trifolium repens) commonly found in grasslands throughout Japan, having been brought here in the form of cushioning materials for packaging
when trade between United States and Japan opened up. In manners such as this, when moving fromplace to place humans bring with them a variety of organisms, whether intentionally or not.
As an example characteristic of transportation, invasive species can be mixed in with the ballast
water of ships. Seawater is held in ballast tanks to help stabilize ships, especially when they are travelingunder light loads. This seawater will often contain many forms of aquatic life, and is released at a different port when the ships take on loads, and so can be carried quite a distance. Many aquatic organisms
contained within can survive until release, especially considering the higher-speed vessels that have beendeveloped in recent years. A well-known example of an invasive species attracting caution in Japan is theMediterranean mussel (Mytilus galloprovincialis). Of course, there are also cases where native Japanese
species are transferred to other locations. One such example is wakame seaweed (Undaria pinnatifida),
which grew explosively in Australia, resulting in major damage to its fishing industry.

Chapter 3: Transportation and the environment｜37

Increased demand for air travel has also promoted the migration of species, resulting in risks tohumans. The most significant uninvited guests transported by aircraft are pathogens and viruses. Examples have been known ever since air travel became a common mode of transportation for tourists, but
the risks associated with increased air travel finally gained wide recognition after 2000 due to severe
acute respiratory syndrome (SARS) and the avian flu. Regarding the latter, the possibility of propagation
overseas via wild birds had already been known, but the danger of the virus being transported by
infected air passengers led to various areas worldwide measuring travelers’ body temperatures using
thermal sensors. Regarding SARS, an infected air passenger in 2003 lead to emergency measures being
implemented in China and throughout the world. Another potential danger is illnesses such as West
Nile fever which are transmitted not directly from person to person but through a vector that can also
be carried on aircraft. Such dangers led to the Ministry of Health, Labour, and Welfare issuing a noticein 2003 titled “Measures against mosquitoes carrying West Nile fever arriving via aircraft from North
America.”

3.5

Toward a low-carbon transportation society

As mentioned earlier, global warming is generally recognized as the
single most serious adverse effect oftransportation. Figure 3 gives statistics for 2012, showing that the transportation sector makes up 18% ofJapan’s total carbon dioxide emissions, and this amount would certainly increase, were the manufac-

16%

0%
3%
7%
2%

33%
21%
18%

turer of transportation vehicles

Energy conversion sector
Residential sector

included as well. However, there has
been a significant decrease of carbon
emissions from the transportation

Figure 3. Carbon dioxide emissions (indirect emissions) by sector inJapan, 2012

Industrial sector
Industrial processes

Transportation sector
Waste

Business and other sectors
Others(created by the author using data from the Greenhouse Gas Inventory Office, National Institute forEnvironmental Studies)

sector since 2000. What was once a
consistent upward trend has now become a major transformation.
Reducing carbon dioxide emissions from transportation requires three basic approaches. One isreducing emissions from vehicles. Another is improving transportation infrastructure. The last, which ismuch needed, is the construction of a transportation system that can help reduce emissions for society
as a whole. This third type of system would include tax reforms and other measures.
Automotive manufacturers in particular are competing to develop and improve vehicles. Spurredin part by soaring fuel costs in Japan in recent years, consumers are increasingly aware of fuel economy.
Hybrid vehicles with better fuel economy than purely gasoline-fueled automobiles accounted for 17% of

38｜Theory

new car sales in 2013. While next-generation automobiles continue to be developed, there has also beensteady progress toward improving fuel efficiency and reducing carbon dioxide emissions for conventional internal combustion engines. Small cars that achieve 40 km/l fuel efficiency are expected to appear
in 2015. The US and the EU have both set upcoming regulations on the amount of carbon dioxide thatcan be discharged by vehicles.
Carbon dioxide emissions can also be greatly reduced through transportation infrastructure
improvements, for example by reducing congestion. In the Tokyo metropolitan area in particular, various measures have been taken to reduce chronic congestion, and carbon emissions have been reducedby constructing new bypasses and highways, among other methods. However, it is also possible thatsuch improvements will result in increased traffic flow and thus increased travel distances, which will
ultimately increase emissions. Recently there have been attempts at making real-time measurements ofchanges in traffic volumes over time, and optimizing traffic signal control according to traffic volumes.
In addition, although they are scarce now, a recent movement has aimed to bring back roundabouts invarious districts of Japan, given their proven carbon emissions–reducing effect.16)
Drastic reduction of carbon emissions will require a transformation of our transportation system.
A variety of measures and technologies have been tested in European cities, including road pricing, carsharing, cycling road development, lowered public transportation fares, increased urban area parking
fees, park-and-drive systems, and providing public transportation information via smartphones to promote the usage of public transportation rather than privately-owned vehicles. Vienna, Austria realized a
10-point increase in public transportation utilization between 1993 and 2012.17) Such efforts toward integration remain rare in Japan. However, Toyama City is frequently cited as a success story for moving
toward becoming a more compact city design and for implementing light rail transit. The greening of
taxation systems related to automobiles has also had a great effect on reducing carbon emissions. Western countries have undertaken tax reform that meticulously considers the environment in relation to therealities of the region.18) Japan too has implemented tax incentives for environmentally friendly vehicles,
and from October 2012 has introduced tax measures related to global warming that add to existing taxes
on petroleum and coal products. The tax rate will be raised in stages through April 2016. Leveraging
revenues from taxes levied as measures against global warming issues will allow for ongoing implementation of energy source CO2 emission reduction, for example through reduced energy usage measures,the proliferation of renewable energy, and the greening and increased efficiency of fossil fuels.

References
1) Japan Economic Research Institute, trans. 1993. “Kotsu to kankyo” [Transport and the environment]. Research Report Vol.
92, No. 13: 1–212. (in Japanese)
2) Organisation for Economic Co-operation for Development. 1988. Transport and the environment.
3) Nakamura, Hideo, Yoshitsugu Hayashi, and Kazuaki Miyamoto, trans. 2004. Toshi kotsu to kankyo: Kadai to seisaku [Urban
Transport and the Environment: An International Perspective]. Institution for Transport Policy Studies. (in Japanese)
4) International Civil Aviation Organization. 2013. Environmental report: aviation and climate change.
5) Japan Automobile Recycling Promotion Center. 2014. “Automobile Recycling Law.” Accessed June 5, 2014. http://www.jarc.
or.jp/automobile/manage/.

Chapter 3: Transportation and the environment｜396) European Environment Agency. 2011. Landscape fragmentation in Europe: Joint EEA-FOEN report. Copenhagen: Publications office of the European Union.
7) Hirasawa, Tsuyoshi. 1996. “The origin and development of a row of trees before modern times in Japan.” IATSS Review Vol.
22, No. 1: 4–12. (in Japanese)
8) Ishikawa, Mikiko. 1993. “A historical study on the establishment of parkways in U.S.A.” J-STAGE Vol. 13: 105–120. (inJapanese)
9) Ishikawa, Mikiko. 2001. Toshi to ryokuchi [Cities and Green Spaces]. Iwanami Shoten. (in Japanese)10) Koshizawa, Akira. 1996. “Evolution of boulevard and street trees in urban planning.” IATSS Review Vol. 22, No. 1: 13–23. (inJapanese)11) Morimoto, Yukihiro, and Akira Kameyama, eds. 2001. Miteigeshon: Shizen kankyo no hozen/fukugen gijutsu [Mitigation:
Conservation of natural environments and restoration technologies]. Soft Science. (in Japanese)
12) Tanaka, Akira. 2010. “Wetlands conservation by mitigation banking: Current status of economic mechanism for biodiversity
offsets: Biodiversity banking in U.S.A.” Journal of Japan Society on Water Environment Vol. 33, No. 2: 54–57. (in Japanese)13) Overseas Eco-roads case investigation group, ed. 1999. Eko rodo bukku: Ikimono to kyousei suru doro zukuri kaigai jire shu[Eco-roads book: A collection of cases from overseas on road construction that promotes coexistence with living things].
Japan Highway Landscape Association. (in Japanese)
14) Loss, Scott. R., Tom Will, and Peter P. Marra. 2014. “Estimation of bird-vehicle collision mortality on U.S. roads.” The Journalof Wildlife Management. Vol. 78, No. 5: 763–771. http://doi.org/10.1002/jwmg.721.
15) Nature Conservation Bureau, Ministry of the Environment, Government of Japan. 2012. Living in harmony with nature:
National biodiversity strategy of Japan.
16) Matsuda, Shoji, Hiroshi Sukigara, and Shigeo Mori. 2014. “Implementation of a roundabout initiative in Iida city.” IATSS
Review Vol. 39, No. 1: 15–21. (in Japanese)17) Wiener Stadtwerke. 2014. “Modal Split.” Accessed June 5, 2014. http://www.nachhaltigkeit.wienerstadtwerke.at/daseinsvorsorge/oepnv/modal-split.html.
18) Imanishi, Yoshikazu, and Masayuki Shibahara. 2014. “Motor vehicle-related tax systems in the U.S. and Europe.” IATSS
Review Vol. 38, No. 3: 182–190. (in Japanese)
Recommended Reading
1) World Conference on Transport Research Society & Institute for Transport Policy Studies. 2004. Urban Transport and theEnvironment: An International Perspective. Emerald Group Publishing Limited.
2) Benedict, Mark A., and Edward T. McMahon. 2006. Green Infrastructure: linking landscape and communities. Washington,
DC: Island Press.
Practical application projects for reference
A land utilization framework and transportation system for declining population: 132–135

Chapter4

Traffic
engineering
Traffic engineering got its start with the popularization of internal combustion vehicles in the early 20th
century, and has developed along with the progress of global motorization that began after World War
II. Traffic engineering traditionally encompasses scientific and technical fields related to reduction of thenegative aspects of automobiles, such as traffic congestion, traffic safety, and pollution (environmentalload). This chapter introduces traffic flow sciences and provides an overview of related technologies.

4.1

Traffic flow fundamentals

The three variables, namely, traffic volume, density, and speed, are fundamental to understand automobile traffic flow on roads.
The term traffic flow rate [vehicles per hour (veh/h)]—or the term traffic volume in general—
describes the number of vehicles passing through a given location per unit time based on the measurement conducted over a duration of 1 h or possibly less. Traffic flow is simply the number of automobiles
passing through a given point, and thus is the traffic demand at the location when there is no traffic congestion. On the other hand, if there is traffic congestion, the traffic volume is equal to the traffic capacityof the downstream bottleneck (see Section 4.2) that causes the traffic congestion.
The term traffic density [veh/km] describes the number of vehicles present at a given time per unit
space length based on measurement conducted over an interval of 1 km or possibly shorter. Unlike traffic volume, direct measurement of traffic density requires simultaneous aerial observation over relatively
long stretches of road and is not very easy.
Traffic speed [km/h] is the representative speed of a traffic flow comprising various vehicles traveling at different speeds. This representative value must be the space mean speed of individual vehicles. It
is calculated by dividing a given space length by the mean of travel times required for individual vehicles
to travel the length. The space mean speed can be estimated by the harmonic mean of the speed of eachvehicle observed at a given location. Using the space mean speed as the traffic speed, Eq. (1) holds.
(Traffic volume Q) = (Traffic density K) × (Traffic speed V)(1)Chapter 4: Traffic engineering｜41

Space
Throughput N1x

V[km/h]Time headway ht

Throughput N2

Measurement distance D

Measurement time T
Traffic flow rate:
Q1 = N1/T [veh/h]Existing count
M1120

Q2 = N2/T

100

100

80

80

60

60

40

40
20

20

0

0
0

20

40

60

40

60

Q[veh/h]Traffic density:
k1 = M1/D [veh/km]

Space headway hs

V[km/h]

120

80

100

80

100

K[veh/km]

0

500

1000

1500

2000

2500

Q[veh/h]

2500
2000
1500
1000
500
0

0

t

Figure 1. Time–space diagram

Time

20

120

K[veh/km]

Figure 2. Example measurement of the relation
between traffic volume, density, and speed

This equation does not generally hold when the simple arithmetic mean is used as the representative
speed of traffic flow. Indeed, Eq. (1) corresponds to the law of conservation of mass in basic physics,
which is universally holds for general flow phenomena, not only traffic flows.
Figure 1 shows time–space trajectories of individual vehicles as well as the relation between traffic
volume and density. As the figure shows, these two variables are in a symmetric relation on the time andspace axes, with the reciprocal of the mean time headway corresponding to the traffic volume, and thereciprocal of the mean space headway corresponding to the traffic density.
Figure 2 shows the mutual relations among the three variables, using actual vehicle detector measurements aggregated in every 5 min and the calculated traffic density obtained by Eq. (1) using themeasured traffic volume and speed. In general, the speed approaches a maximum value (the free speed)
as traffic density approaches zero, and traffic density approaches a maximum value (the saturation density) as speed approaches zero. These two variables are in a monotonically decreasing relation. Furthermore, there exists a maximum traffic volume reached at a certain value of traffic density (the criticaldensity) and a certain value of speed (the critical speed). Densities above the critical density and speeds
below the critical speed indicate a state of traffic congestion; conversely, densities below the critical density and speeds above the critical speed indicate an uncongested traffic state.
Using the monotonic decreasing relationship between density and speed combined with Eq. (1), it
is straightforward to show that the traffic volume–density (volume–speed) relationship is a binary function that has a maximum value of traffic volume. This is the theoretic basis for the existence of a maximum traffic volume (capacity) for road traffic.

4.2

Features of traffic congestion

4.2.1 Bottlenecks and the definition of traffic congestion
Traffic congestion is defined as a traffic state (a waiting queue) in which queued traffic (congested vehicles)

42｜Theory

develops upstream from a traffic capacity bottleneck that occurs when traffic demand exceeding the bottleneck traffic capacity attempts to enter the bottleneck. A bottleneck is a road section in which traffic
capacity is relatively low in comparison with upstream and downstream road segments. Traffic congestion on inter-city expressways in Japan is generally triggered at sag sections (road sections with longitudinal slope changes from downward to upward) or at tunnel entrances.1) On the other hand, major bottlenecks on European or American expressways are merging or diverging sections and weaving sections.
Major bottlenecks on surface streets are key signalized intersections with heavy traffic, queues formingat parking garages of large shopping centers, and on-street parked cars. From the definition of traffic
congestion, it is obvious that there is no fixed speed threshold to distinguish congested traffic conditions
from uncongested traffic conditions. For simplicity, 40 km/h on inter-city expressways and 20 km/h onurban expressways are used as the thresholds to identify traffic congestion for practical use in Japan.
4.2.2 Calculating traffic congestion
Figure 3 shows a simplified assumption of the volume–density relationship per lane based on the data
shown in Fig. 2. Figure 4 schematically shows the change in traffic congestion caused by a bottleneck on
a time–space diagram. Point a (traffic volume A, traffic density k1, velocity v) in Fig. 3 represents the
traffic conditions of traffic demand A attempting to pass through a bottleneck with capacity Cb (location
BN in Fig. 4). Here, in the case where A > Cb, traffic congestion occurs upstream of the bottleneck (pointb in Fig. 3; traffic volume Cb, traffic density k2, velocity vb), and the tail of the congestion queue moves
upstream. The shock wave speed uab is given by the following Eq. (2) according to shock wave theory:2)
uab = ( A − Cb ) / ( k1 − k2 )(2)
The shock wave speed uab is the slope of the line connecting a and b in Fig. 3. The slope in Fig. 3 isobviously negative, which indicates that the shock wave moves upstream. The boundary between
demand traffic condition a and traffic congestion b moves at speed uab in Fig. 4. If the traffic demandchanges to point c in Fig. 3 (traffic volume A', traffic density k3, velocity v) and A' < Cb holds at time T1,then ucb is positive, meaning that the tail of the congestion queue shortens until it vanishes at time T2.
For example, when traffic demand A=1800 veh/h arrives at a bottleneck with capacity Cb=1600
Q [veh/h]
2000
A
Cb
A'

Space

a

uab

b'
c

Status b'

v

BN

vb

b

ucb

uab

Statusb
ucb

Status a

v vb
k3 k1
k2' 25k2[veh/km]K
125

Figure 3. A model of traffic volume–density relation

Status cv
0T1

T2 TimeFigure 4. Expansion and reduction shock wave of traffic congestion

Chapter 4: Traffic engineering｜43

veh/h, the tail of traffic congestion moves upstream at a speed of uab = (1800−1600) / (22.5−50) ≈ –7
km/h, so if T1 = 2 h, the traffic congestion length L ≈ 14 km. If the traffic demand decreases to A' = 1500
veh/h at time T1, then ucb = (1500−1600) / (18.75−50) = 3.2 km/h and time T2 is T1 + L/ucb ≈ 6.5 h.
It is generally known that the excess of traffic demand over the bottleneck capacity is at mostapproximately 12–15% (in the case of this example, it is 12.5%, as given by 1800/1600 = 1.125) evenwhen traffic congestion occurs due to an increase in traffic demand. It is also known that the duration of
traffic congestion (6.5 h in this case) greatly exceeds the duration of traffic demand exceeding the capacity (2 h).3)
4.2.3 Features of traffic congestion on ordinary expressway sections
It was recently found that on inter-city expressways in Japan, bottlenecks at sag and tunnel entrance sections together account for 80% of all bottleneck sections.4) There is no merging or traffic signals at suchsections, but slight speed perturbations due to slight changes in slope cause speed reduction shock waves
that propagate upstream, causing traffic congestion. The level of traffic demand causing such phenomena varies widely in the range of 75–90% of the normal capacity for ordinary expressway sections. Thisvariation is thought to be due to the differences between individual drivers and between vehicle types in
car-following behavior.5)
Furthermore, once traffic becomes to traffic congestion, the bottleneck capacity declines further, toaround 60% of the normal capacity for ordinary expressway sections. This is because drivers’ carfollowing behavior becomes sluggish due to driver boredom and fatigue caused by the low speed in traffic congestion.5) Assume traffic demand is 1800 veh/h per lane as shown in Fig. 3, and the reduced bottleneck capacity is 1600 veh/h per lane, which is equivalent to 80% of an ordinary expressway section’s
normal capacity of 2000 veh/h per lane. The speed of extension of the traffic congestion tail is calculated
to be approximately 7 km/h (see Section 4.2.2). If the reduced traffic capacity after formation of traffic
congestion is 1200 veh/h per lane, which is equivalent to 60% of the normal capacity of an ordinary
expressway section, the speed of extension of the traffic congestion tail doubles, to approximately 14
km/h based on Fig. 3 and Eq. (2). At a sag section, the traffic capacity is further lowered after formationof traffic congestion, and causes a rapid increase in the length of the traffic congestion queue. Furthermore, even when the traffic demand is reduced, the duration of traffic congestion is prolonged because
the traffic congestion queue shortens at a lower speed. These are the reasons why congestion on expressways easily grows and persists.

4.3

Traffic performance-oriented planning and design of road networks

Expressways are the main arteries for high-volume, high-speed automobile transportation. They include
long-distance nationwide expressways that form the backbone of the national transportation network,
expressways that constitute major networks within regional areas, and urban expressways within large
cities. For surface roads accepting more variety of transportation modes including pedestrians and44｜Theory

cyclists, there are different functional classifications according to connectivity scale. Roads in cities furthermore perform various non-transportation functions, such as providing space for infrastructure likesewage and gas lines and performing disaster prevention functions to prevent the spread of fire. This
makes such roads within cities (streets and avenues) quite different from inter-city roads (expressways
and highways). In recent research activities in Japan, focus has been placed on such difference in transportation functions in hierarchical road classifications the concept of “performance-oriented” road planning and design has been promoted with the goal of attaining a road network that provides a certain
level of traffic service functionality.6)
Junctions, the crossing points ofroads, are key locations for transPhase 1

Phase 1

Phase 2Phase 2Phase 3Phase 3Phase 4Phase 4

Figure 5. Example of traffic control improvement at a key signalizedintersection

portation and are one of the mostimportant elements for ensuring
hierarchical road functionality.
Many traffic capacity bottlenecks areat junctions, especially at key signalized at-grade intersections of surface
streets. At intersections where traffic
demand is concentrated, there areneeds for proper geometric design(a sufficient number of lanes, grade
separation, traffic islands, etc.) andfor traffic signal phasing plan andoptimization of signal control parameters (cycle, green split, and offset) to prevent the occurrence oftraffic congestion (Fig. 5).
There are many intersections where the capacity (Cb) is high enough so that they are free from traffic congestion and capacity bottleneck. Even when the traffic demand D is extremely low (0 to D ≪ Cb),
waiting time (delay) occurs at signalized intersections corresponding to the signal control parameters.
On the other hand, when traffic demand exceeds a certain volume (D > Q0) at an unsignalized intersection, the delay under unsignalized control may exceed that under signalized control. For intersections
with moderate demand (0 ≪ D to Q0 < Cb), roundabouts have attracted attention in recent years in Japanas a method for both reducing delay and greatly reducing the risk of rear-end collisions and deai-gashiracollisions (collisions that occur when vehicles, bicycles, pedestrians, etc. suddenly enter into an intersection) frequently observed at unsignalized intersections. There has been increasing momentum for the
introduction of roundabouts in Japan.
To ensure a certain level of transportation functionality for arterial roads, it is important that traffic
flow on arterial roads not be inhibited much at minor intersections. Effective means to that end include
techniques concerning road geometric design and traffic operation and control, such as not connecting
minor streets to arterial roads, limiting the allowance of traffic entering/exiting arterial roads by left
turns only, and providing a dedicated auxiliary right turn lane (or pocket) at the median of arterial roads

Chapter 4: Traffic engineering｜45

to separate this exiting right turn traffic from the main traffic stream on the road. The concepts describedabove are called “access management” in the United States7) which aims to establish a systematic
scheme.

4.4Road traffic management-based countermeasures

4.4.1 Fundamental ideas
The basic concepts of countermeasures for traffic congestion reduction or elimination are adjusting traffic demand and increasing bottleneck capacity. The former includes well-known traffic demand management (TDM), as well as additional efforts toward more dynamic adjustment methods in recent years
such as providing traffic information and route guidance. The latter mainly includes physical measures
such as increasing the number of lanes and expanding road networks, and additionally entails the introduction of active traffic management (ATM), which has been popular in Europe in recent years (see Section 4.4.2).
Improving traffic safety requires a more multifaceted approach that includes not only traffic engineering, but also vehicle technologies and the elucidation of human factors. Traffic congestion, particularly on expressways, is a significant cause of rear-end and near collisions of vehicles, and therefore, traffic congestion alleviation measures may also significantly reduce such accidents.8) It is important to let
drivers naturally understand the road geometric structure and conditions by applying proper road alignment, arrangement planning of intersections, and so forth. Appropriate setting of overall traffic restrictions, including signal control planning, may also result in highly safe spaces for expressways, as well as
for surface streets which are shared with pedestrians and cyclists.
Environmental impacts due to road vehicular traffic include noise, air pollution, and greenhousegas emissions. Improvements in automobile performance and fuel quality have resulted in significant
lessening of noise and air pollution problems in Japan in recent years, and improved fuel economy has
reduced carbon dioxide emissions. Nonetheless, traffic congestion and repeated stopping and starting
caused by traffic signals would lead to needless carbon dioxide emissions, 9) and therefore any trafficsmoothing policies to alleviate traffic congestion or to reduce number of stops are effective at reducing
the environmental impact of road vehicular traffic.
4.4.2 Expressway traffic measures
Expressways are motorways (dedicated roads for automobiles) that serve as the main arteries for highvolume, high-speed nationwide and urban transportation. Frequent traffic congestion on expressways isa functional failure of these arteries, and leads to major losses to the country and to regional communities. Reducing congestion, especially on expressways, is thus extremely important. Ramp metering,which controls traffic volume at on-ramps, has become a common measure, and ATM such as lanebased variable speed limits (Fig. 6) and temporary hard shoulder opening has also been popular indeveloped countries except Japan.

46｜Theory

Particularly severe traffic congestion was expected
to be caused by partial opening of the Shizuoka segment of the New Tomei Expressway due to traffic concentration on the Tomei Expressway section between
the Otowa-Gamagori Interchange and Toyota Junction
prior to opening the Aichi segment. Therefore, a policy
was implemented that increased the number of traffic
lanes on the Tomei Expressway by narrowing them asshown in Fig. 7, while keeping road width unchanged.10)
This measure in Japan resulted in a great reduction of

Figure 6. Example of lane-based variable speed
limits (U.K.)

traffic congestion and traffic accidents on the Tomei
Expressway section. An advanced automotive technology that has recently been attracting attention isadaptive cruise control (an advanced form of cruise control, which automatically maintains a constant
speed). Adaptive cruise control adjusts the vehicle’s speed and spacing ahead to conform to the leading
vehicle’s behavior. Because drivers’ car-following behavior is a prime cause of bottlenecks on ordinary
expressway sections (see Section 4.2.3), adaptive cruise control technology is expected to help reduce
traffic congestion.11)

Figure 7. Increase to three lanes between the Otowa-Gamagori Interchange and the Toyota Junction on the Tomei
Expressway (source: NEXCO Central Nippon Expressway Co., Ltd. press release)

4.5

Future trends in traffic management

One issue in traffic engineering is the extreme difficulty of running laboratory experiments. This makes
careful practical observations and investigations in the field important. Small differences and changes intraffic flow, such as 10–20% variations in traffic demand and the emergence of traffic congestion at sag
sections due to individual differences in driver behavior, can have a significant impact on the characteristics of traffic flow: whether it is congested or uncongested. The conventional point observations withvehicle detectors described in Section 4.1 have limitations to describe such temporal and spatial
variations.
Advanced information technology has enabled the establishment of “probe” technology that allows

Chapter 4: Traffic engineering｜47

temporally and spatially continuous measurement and monitoring of traffic status via automobilemounted navigation systems or drivers’ smartphones. Complete knowledge of the overall quantitative
features of traffic flow, however, remains difficult because such techniques provide only sampled data.
An estimation method of the overall traffic state in combination with data from vehicle detectors
and probe data has recently been developed by applying the traffic flow theory described in Section
4.2.12) It is expected that the accumulation of large amounts of detector and probe data and the application of recent data mining technologies will provide dramatic increases in our knowledge of overall traffic states. Based on knowledge derived from such accumulated data, real-time use of sensor and probe
data will allow the establishment of “nowcast” technology13) to estimate the current traffic state throughthe application of theory-based traffic simulation models. The dynamic flexible application of nowcast
technology applied to traffic information provision, route guidance systems, and ramp metering and
TDM measures should result in minimization of daily recurrent traffic congestion. The nowcast technology is also considered to allow for prompt planning and execution of countermeasures against bad
weather, large events, traffic accidents, and other incidents that are difficult to predict.
For example, Fig. 8 shows the state of extraordinarily massive traffic congestion that occurred on
major arterial roads in the Tokyo Metropolitan Area
immediately after the Great East Japan Earthquake
on March 11, 2011.14) Gridlock, which is the phenomenon where an entire road traffic network becomesparalyzed, emerged on that day. Gridlock can be
defined as the traffic state where the throughput of abottleneck is reduced to a value lower than the original bottleneck capacity by the tail of a traffic congestion formed upstream of the bottleneck extending to
Figure 8. Gridlock of arterial roads in Tokyo
the bottleneck location on a loop-shaped road network. Gridlock is a serious traffic congestion phenomenon that is extremely difficult to resolve once it
starts. It is believed that the development of a system for real-time detection of gridlock, or the establishment of traffic control methods for predicting and avoiding it, would be a significant contribution
leading to increased stability and reliability of road transportation systems.
References
1) Koshi, M. 1985. “Traffic Flow Phenomena in Expressway Tunnels.” IATSS Research Vol. 9: 50–56.
2) Lighthill, M. J., G. B. Whitham. 1955. “On Kinematic Waves: 2. A Theory of Traffic Flow on Long Crowded Roads.” Proceedings of the Royal Society of London A Vol. 229: 317–345.
3) Koshi, M., H. Akahane, and M. Kuwahara. 1989. “Explanation of and Countermeasures against Traffic Congestion.” IATSS
Research Vol. 13, No. 2: 53–63.
4) http://www.mlit.go.jp/road/ir/ir-council/autopilot/pdf/05/6.pdf.
5) Koshi, M., M. Kuwahara, and H. Akahane. 1992. “Capacity of Sags and Tunnels on Japanese Motorways.” ITE Journal Vol.
62, No. 5: 17–22.
6) Oguchi, T. 2008. “Redesign of Transport Systems on Highways, Streets and Avenues.” IATSS Research Vol. 32, No. 1: 6–13.

48｜Theory

7) Transportation Research Board. 2003. Access Management Manual.
8) Oguchi T., H. Akahane and Y. Yamada. 2004. “Analysis of Accident Rate in Critical Condition of Traffic Flow on Expressways.” Traffic Engineering Vol.39, No.3: 41-46. (in Japanese)
9) Oguchi T. and M. Katakura. 2000. “New Conceptual Evaluation Method of Amount of Exhaust Emission Gas on VehicularRoad Traffic.” Advances in Transport (Urban Transport VI) Vol.6: 383-392.
10) http://media2.c-nexco.co.jp/images/press_conference/78/2918114934ea7888494e01.pdf11) Kanazawa, F., K. Suzuki, K. Sakai, and K. Iwatate. 2013. “Conducting the FOT to Evaluate the Driving Practice for Smooth
Traffic to Mitigate Traffic Congestion at Sag Sections on Expressways. ” In Proceedings of 20th World Congress on ITS.
CD-ROM.
12) Mehran, B., M. Kuwahara, and F. Naznin. 2012. “Implementing Kinematic Wave Theory to Reconstruct Vehicle Trajectories
from Fixed and Probe Sensor Data.” Transportation Research Part C Vol. 20: 144–163.
13) Hanabusa, H., M. Kobayashi, K. Koide, R. Horiguchi, and T. Oguchi. 2013. “Development of the Nowcast Traffic Simulation
System for Road Traffic in Urban Area.” In Proceedings of 20th World Congress on ITS. CD-ROM.
14) Oguchi, T., M. Ito, R. Mizuta, R. Horiguchi and M. Iijima. 2013. “Analysis with Traffic Simulation and Evaluation of Traffic
Congestion Mitigation Measures for the Tokyo 23-wards at a Great Earthquake Disaster. ” Proceedings of Traffic Engineering
Meeting, Vol. 33: 273-278. (in Japanese)
Recommended Reading
1) May, A. D. 1990. Traffic Flow Fundamentals. Prentice Hall.
2) Daganzo, C. F. 1997. Fundamentals of Transportation and Traffic Operations. Elsevier Science.
Practical application projects for reference
Practical optimal signal control emphasizing pedestrian road crossing realities: 144–147
Significant reduction of cycle length via a two-stage crossing system: 148–151
A study on the practical deployment and promotion of safe and ecological roundabouts: 152–155
A study on the role and limitations of motorcycles as a means of urban transport in Southeast Asia: 156–159

Chapter5Intelligent Transport
Systems
5.1

An introduction to ITS

5.1.1 What is ITS?
The term ITS was coined in 1994, and stands for “Intelligent Transport Systems” or “Intelligent Transportation Systems.” In a broad sense, an ITS is a system relating to mobility that has increased in sophistication through information technology (IT). However, the specific terms and concepts differ according
to the country and situation.
The Japanese government and the specified nonprofit corporation, ITS Japan, use “kodo doro kotsu
shisutemu,” meaning “intelligent road and transportation systems,” but the Institute of Electronics, Information and Communication Engineers, the Information Processing Society of Japan, the Institute ofElectrical Engineers of Japan, and others use “kodo kotsu shisutemu,” which in English means “intelligent
transport systems.”
As Fig. 1 shows, The Ministry of Land, Infrastructure, Transport and Tourism defines an ITS as “anew transport system constructed with the goal of alleviating road traffic problems such as accidents
and congestion using state-of-the-art information and communication technologies to create an information network based on people, automobiles, and roads.”1)
ITS Japan explains the concept as, “a system for solving a variety of problems that road traffic faces,such as accidents, congestion, and environmental measures, through the exchange of information
between people, automobiles, and roads. It attempts to coexist
with the environment and improve energy efficiency by elimiPeople
nating accidents and congestion while at the same time optimizing the road network by utilizing state-of-the-art information and communication and control technologies. In
addition, it has the potential to create new industries andmarkets with its diverse related technologies, and promises tobe a driving force in changing the social system.”2)
In each academic society listed above, ITS are not limited

Information andCommunication
Roads Technology Vehicles
Figure 1. The Ministry of Land,
Infrastructure, Transport and Tourism’s ITS1)

50｜Theory

to automobiles, but also include railways, aircraft, and shipping traffic as areas that can also benefit fromthe sophistication of mobile IT. This mobility-oriented concept is popular in other countries, especiallyin Europe.
5.1.2 Organizations promoting ITS
In a variety of countries, ITS are promoted by a wide range of organizations including governments,
local governments, industries, and academic societies. For example, as of 1996 the ministries and agencies promoting ITS in Japan were called the “five concerned ministries,” consisting of the National Police
Agency, Ministry of International Trade and Industry, Ministry of Transport, Ministry of Posts and Telecommunications, and Ministry of Construction. After subsequent reorganization and renaming, there
are currently many more ministries and agencies involved, including the Cabinet Secretariat, Cabinet
Office, National Police Agency, Ministry of Internal Affairs and Communications, Ministry of Economy,
Trade and Industry, and Ministry of Land, Infrastructure, Transport and Tourism. Also, ITS Japan, aspecified nonprofit corporation, has been essential in the promotion of ITS in Japan. ITS Japan has taken
the role of Secretariat of the ITS World Congress and ITS Symposium, and is responsible for the publication of academic journals such as the International Journal of ITS Research. It actively promotes ITS
activities in the spirit of international cooperation among industry, government, and academia.
The ITS World Congress, described later, is a trilateral symposium held every year, rotating
between Europe, Asia, and the United States, and centering around the European Road Transport Telematics Implementation Coordination Organization, which is a private-public organization for promoting ITS in Europe, the Intelligent Transportation Society of America, which is a nonprofit scientific andeducational organization for the purpose of ITS promotion and serves as the official advisory committeeof the US Federal Department of Transportation, and ITS Japan. Moreover, there are many other private–public organizations promoting ITS in each country and together with the efforts of a variety ofuniversities and research institutes, ITS are receiving broad promotion.
In addition to the IEEE and Transportation Research Board in the United States and the three Japanese academic societies mentioned above, other academic societies, such as the Society of Automotive
Engineers of Japan, the Japan Society of Civil Engineers, the Japan Society of Traffic Engineers, and theInternational Association of Traffic and Safety Sciences, are also involved in the promotion of ITS. ISO/TC 204 - Intelligent Transport Systems plays a central role in standardization, but coordination with
International Telecommunication Union is still undertaken, especially in the field of information andcommunication.
5.1.3 Aims of ITS
According to the definition of ITS, the range and concept used in each field may change, but the purpose of ITS generally relates to the “safety, efficiency, environmental concerns, and convenience of traffic
and transport via the thorough utilization of IT.” Therefore, changes in information and communication,
positioning, and underlying sensing technology by means of lifestyle and value changes as well as theadvancement and dissemination of science and technology, always bring about changes in the ITS world.

Chapter 5: Intelligent Transport Systems｜51

The next section will review the history of ITS.

5.2

History of ITS

5.2.1 The beginning of the ITS World Congress and the transition of Japan’s ITS
The annual World Congress on Intelligent Transport Systems (hereinafter, World Congress) was first
held in Paris in 1994, and the following year saw it held in Yokohama. The first World Congress wasnamed and positioned as “The First World Congress on Advanced Transport Telematics and Intelligent
Vehicle-Highway Systems,” and the theme was “Towards an Intelligent Highway Transport System.”3)
The name was officially changed to contain ITS at the second World Congress. Japan enthusiasticallyembraced ITS following the Congress in Yokohama in 1995, and in 1996 the “Grand Plan to Promote
Intelligent Transport Systems (ITS)” was established by five concerned (then-) ministries and ITS has
been actively promoted ever since. Figure 2 shows the subsequent timeline.
The period from 1996 until mid-2004 came to be known as the first stage of ITS. As of 2014, 21
services in 9 fields have been launched, such as the widely used Vehicle Information and Communication System (VICS), which is representative of a sophisticated navigation system, and Electronic Toll
Collection (ETC).4)
An ITS is one system made of many, and understanding of the underlying systems is important tounderstand the system as a whole. Many of these were small-scale systems created as dedicated systems
for their various uses (system by system). Recently, systems tend to be applications or “apps” built onFirst Stage

Second Stage

Next-Generation ITS(Promotion of practical implementation) (Dissemination and accelerated spread (Responding to social challenges)of the technology through society)1996
Five concerned ministries

2004
Japan’s ITS Promotion Council

Automatic toll collection system
Safe driving support
Traffic management optimization
Road management efficiency
Public transport support
Commercial vehicle efficiency
Pedestrian support
Emergency vehicle operations support

1995
World Congress in Yokohama

Facilitation and environmentalload reduction

Improved convenience

Regional activation

Foundation development
and internationalization

2004
World Congress in Nagoya

Figure 2. The flow of Japan’s ITS4)

Recommendations for future creations by the ITS

Enhanced safety

ITS Promotion Guidelines

The grand design of ITS Promotion

Sophisticated navigation system

2013
ITS Japan

2013
World Congress in Tokyo

Realization ofsustainablemobility

52｜Theory

platforms. For example, the creation of a word processing application running on top of an OS platform
on a home computer, which led to the disappearance of the word processor as a dedicated machine, or
the increased rate of smartphone use after the development of apps that could run on mobile platforms
such as Android or iOS, which ushered in a decline in the use of standard portable handsets or featurephones. Such a shift has also seen dedicated car navigation systems making the changeover to car navigation apps running on smartphones. In short, the shift from dedicated systems to platform oriented
systems is a significant change (Fig. 3).

Application (App) N

Application (App) 3

Application (App) 2

Application (App) 1

System N

System 3

System 2

System 1

・・・

・・・

・・・

Platform
Figure 3. Platform-oriented. System implementation using applications running on a platform

In 2004, the Japan ITS Promotion Council released its “ITS Promotion Guidelines,” the pillars ofwhich are “safety and security, environment and efficiency, and comfort and convenience,”4) and represent a top level purpose-oriented concept with the main thrust being that each system is integrated andrunning on a platform. For examples of various projects see Reference 4.
The first stage of promotion was the practical use of the technology, the second stage was the dissemination and accelerated spread of the technology through society, and since 2010, the realization of asustainable mobile environment has been promoted as the next generation of ITS’s response to social
issues. For the future of ITS, in light of the changes in both the societal and technical contexts, efforts
continue toward the expansion of regional ITS and the realization of a next-generation mobility society.
These efforts can be summed up in eight points:4)
1. Construction of a safe and secure transport system
2. Construction of a next-generation automobile society
3. A response to environmental needs
4. A response to the development of information and communication technologies
5. A response to the movement of next-generation people and goods
6. The introduction and promotion of an integrated regional ITS
7. Disaster response
8. A response to internationalization
5.2.2 The history of related fields
Although the term ITS was coined in 1994, as previously mentioned, its origins can be traced back to
the 1980s with programs that used sensing, information and communication, and signal processing andChapter 5: Intelligent Transport Systems｜53

information processing to achieve a greater sophistication of traffic and transport, such as the Partners
for Advanced Transportation Technology (PATH) Program in California in the United States and thePROgraMme for European Traffic with Highest Efficiency and Unprecedented Safety (PROMETHEUS)
in Europe. Furthermore, if projects in Europe, America, and Japan such as automated driving, route
guidance, and the provision of traffic information are included, the origins can be traced back to the1950s.5) Please refer to existing literature6) that explains the needs and legislation required regarding thetransition of research and development of automated driving, which began in the 1950s and comes up
to the present day with Japan’s ITS research and development projects on vehicle convoys traveling
together in a line for increased energy efficiency.
5.2.3 System architecture
The system architecture conceptually represents interactions between the elements of each system andthe system as a whole, as if laid out on a nautical chart, to achieve the system’s objectives, and is intended
to effectively advance the development of systems that require time to realize their large-scale practicalapplications and to spread through society. The purpose of system architecture development is to construct integrated systems efficiently, to ensure the scalability of the system, as well as to promote national
and international standardization.
The system architecture in Japan that was formulated in the late 1990s (see Fig. 4) includes a complete picture (see Fig. 5) of the user service system, which is a premise of the plan.7)

PeopleCenterCollection/provision of external information

Collection/provision of organizational information

Detection (accidents, vehicles,
drivers, obstacles, people)

Movement plan management

Road traffic information management(movement path, traffic, weather)

Movement path planning management

Human interface unit

(possible replacement for wide area wireless communications such as satellite communications or broadcasting)

Short-range communications (road-to-vehicle*)

Short-range communications (vehicle-to-vehicle)

Vehicle control

Public transport service information management

Wired communications

Wide-area wireless communications

VehicleTraffic flow control plan management

Wheelchair management

Road traffic information management(movement path, pathway, site, traffic, weather)

Road traffic information management (movement path)

Vehicle information management

Toll collection management

Human interface unit

Accident information management

Detection (accidents, obstacles, people, goods)

External

Roadside- Provision of
travel/tourism/entertainment
related information- Provision ofbusiness/media/government
related information- Provision of route/facilities
information- Provision of support for
emergency activities/disasterprevention information- Information network access- Banking services- Public transport authority usage
and reservations/checkins/ticketing services/etc.

Fee calculations
Movement path planning management
Road traffic information management
Traffic flow control plan management
Detection (accidents, vehicles, obstacles)
Human interface unit

*Short-range communication (road-to-vehicle) indicates narrow range communication that takes place between the roadside and the vehicle/people.

Figure 4. System architecture (interconnected subsystems)7)

54｜Theory(User services)(Individual user services)(Sub-services)

1. Sophisticated navigation system(Development field)(1) Provision of traffic-related information(1) Provision of routeinformation to the driver

1. Provision of optimal
path information

2. Automatic toll collection system(3) Automatic toll collection(2) Provision of destination information(2) Provision of other institutional
information to the driver(4) Provision of driving environment information

3. Safe driving support

2. Provision of roadtraffic information
3. Provision of traffic jam/congestion information(time required, etc.)(5) Risk warnings

4. Reliable guidancealong selected route(6) Driving assistance(7) Automated driving(8) Optimization of traffic flow

4. Traffic management optimization(9) Provision of traffic control information when a traffic accident occurs

ITS(10) Maintenance work efficiency

5. Road management efficiency(11) Management of special vehicles(12) Provision of traffic regulation information
6. Public transport support(13) Provision of public transport usage information

7. Commercial vehicle efficiency(15) Commercial vehicle operations management support(14) Public transport operations, operations management support(16) Continuous automated driving of commercial vehicles
8. Support for pedestrians and others(17) Route guidance(18) Hazard prevention

9. Emergency vehicle operations support(19) Automatic emergency notifications(20) Emergency vehicle route guidance and relief activities support(21) Use of advanced information and communication technologies for information related to society

9

21

56

172
7)

Figure 5. Overview of proposed system architecture development for user service system

5.3

ITS fields and research and development themes

5.3.1 Overview of the fields of ITS
The different fields of ITS, from their fundamental technologies to their surface applications, are manylayered and the expansion of
System technologies/services/policies
these fields is similarly diverse.
As Fig. 6 shows, the frameworkof ITS fields are supported bytheir respective fundamental

Environment

Convenience

Other
systems

Recreation

ITS architecture/probe/ITS platform

Figure 6. Framework of ITS fields

Other fundamental
technologies

Fundamental technologies

ITS map technology

ITS HMI technology

ITS control technology

pedestrian services for the various functions provided by the

Efficiency

ITS sensing technology

as safe driving support services,traffic control services, andSafetyITS positioning technology

tion and communication, positioning, and sensing, and there
are numerous applications such

Traffic
Transport planning/ Pedestrian Environmental and Logistics Telematics
control road management system systemenergy system system

ITS information andcommunication technology

technologies such as informa-

Accidents andsafety system

Chapter 5: Intelligent Transport Systems｜55

fundamental technologies in the middle layer of the platform.8)
The technologies that underlie the applications change with the passage of time. For example, thetransition from dedicated information and communication, positioning, and sensing systems to all-purpose mobile phones, Wi-Fi, Bluetooth, and smartphones with built-in body sensing capabilities create
the landscape in which new applications are released. In addition, the continued evolution of each fundamental technology and system technology also sees the evolution of the safe driving support systemfrom simple danger warnings to assisted safe driving technologies to automated driving systems.
Figure 6 shows the universal and abstract concepts persistent through time from the fundamental
technologies to the surface applications.
5.3.2 Changes in trends of the ITS world, and research and development themes
Originally, the essence of ITS was mostly
Expansion of human perception range for action/decisionawareness enhancement (Fig. 7). Safe driving support systems such as danger warn-(Bring an understanding of the macro level to an understanding of the micro level)- Safety improvements- Efficiency improvements through route selection,
prevention of frustration- Economic effects of digital signage and excursions(excursions make changes down to the ground level,
context marketing)ing systems that inform the driver of risks
looming beyond the range of their field ofvision, wide-area real-time traffic inforUser’s position
mation that cannot be known by drivers
themselves, and the forecasting of potential areas of congestion all assist the driverin taking actions to avoid risks and inconveniences. They also inform drivers about
Figure 7. Awareness enhancement in the ITS fields
current road surface conditions and canalert the driver thereby helping to prevent accidents. Technologies spread out from there to anti-lockbraking systems (ABS) and collision avoidance systems assisting the driver in vehicle operation. Generally, these changes represent a transition from after-the-fact passive safety to before-the-fact active safety,
paving the way for automated driving at various levels.
VICS is a system transmitting traffic information, and initially collected sensing data from relatively large road systems using infrastructure-mounted sensors such as loop coils or ultrasonic sensors.
However, these data can fundamentally be collected only in areas close to the sensor locations. In contrast, systems developed over the past 10 years use probe car (floating car) data and then upload thosedata, including position, directly to servers on information networks. These systems are able to grasp
traffic conditions by aggregating collected data and delivering traffic information to each vehicle. Thismethod is able to select a single car from a group, and does not require any additional investment for
infrastructure such as installing new sensors. The data collected are not limited by the installation positions of the sensor infrastructure, as long as the car passes a sensor, the data are collected. However, thistype of probe system is not favorable overall. Although the installation locations of the infrastructure
sensors are limited, the traffic data collected are fine-grained. In contrast, the probe system relies on
absolute traffic volume and the proportion of sensors installed over the entire road system to determine

56｜Theory

the quality of the data. At lower traffic volumes the precision and accuracy of the data collected falls, and nodata are collected at all if no vehicle
containing a transmitter passes thetarget area, since a vehicle without atransmitter does not work as a probe.
One example of using this feature is the collection of probe car data
immediately after the Great East
Japan Earthquake on March 11, 2011.
Figure 8 shows this example. The
portions in blue show traffic data
within a 24-h period after the earthFigure 8. Example of probe information system (Honda Internavi
quake. Note, however, that the figure
traveling experiences immediately after the Great East Japan
does not always show the traffic data
Earthquake)9)
for all potentially passable roads, it
simply shows four-wheeled passenger vehicles passing the sensor locations within a 24-h period. Furthermore, it does not show motorcycles or large transport vehicles using the roads; if a driver had not
happened to use the road, no trace would have been recorded at all. It also does not show the passage oftraffic on roads that are not colored blue. Yet, there is no doubt that these data were very important
information in supporting activities during the disaster situation.
A system using probes to gather data from smartphones is able to gather data with even finer granularity. While probes installed in vehicles provide data for only that single vehicle, probes transmittingfrom a smartphone can render extremely fine-grained position and direction data from people on buses,
trains, and riding in cars; pedestrians on streets and in underground malls; and people inside buildings.
It is also possible to process various pieces of uploaded data on the server side depending on conditions.
The use of smartphones as probes certainly reduces the size of the entity operating the system fromthe national level to the size of major companies, and in the future it is entirely feasible that this level
will again be reduced to encompass small and medium-sized organizations.
In addition, even though smartphone applications may be partly inferior to a dedicated car navigation system, the fact that many applications can replace dedicated systems is a clear indication of themove toward lightweight solutions.
ETC is a system that automatically collects user toll fees to pay for road construction and maintenance costs from vehicles using the road, so for this purpose it is not absolutely necessary that the user’svehicle pass through a gate. It is possible to levy the toll using indexed routing information from theposition data. If this is to become a reality, a system function preventing users from eluding the toll
charge will become necessary.
Now, let us discuss the role of positioning infrastructure as a fundamental technology. There is noChapter 5: Intelligent Transport Systems｜57

doubt that the most prevalent positioning infrastructure is GPS. However, in recent years, methods foracquiring specific position data by using the MAC address and RSSI of Wi-Fi access points are notably
becoming the second-most used technique for acquiring location information and position information,
representing positioning social infrastructure. With the addition of Bluetooth low-energy (BLE), positioning infrastructure has come to have a heterogeneous system structure. Similarly, this is also a contributing factor in the move toward lightweight solutions. Positioning using GPS requires a nationallevel endeavor; however, positioning using Wi-Fi and BLE has now become possible for companies andsmaller organizations. Of course, there are both strong and weak points in the environment for theapplication of GPS, Wi-Fi, and BLE. GPS excels in outdoor environments, particularly in mountainous
regions, at sea, and the like where there are few tall buildings. Wi-Fi is robust in urban areas, particularly
where users are inside buildings or underground shopping centers. BLE exerts its strength indoors. Thisis an additional contributing factor in the movement toward lightweight solutions.
Finally, there are expensive dedicated vehicles for detecting the condition of road surfaces damaged
by disasters. In contrast, by using the acceleration sensor information from smartphones attached to thedashboard, a system for detecting certain vibrations in the vehicle caused by damage to the road has
been put to practical use. The sensor accuracy of the dedicated vehicle is high but the speed of the vehicle is slow. On the other hand, the accuracy in systems using smartphones is low but data are continually
collected while the user is on the move. This is a further example of a lightweight solution.
5.3.3 Topics in 2014 and future development4)
ITS Japan has summarized the seven priority areas for the future development of ITS as follows:
1. The reduction of traffic accidents and road congestion to zero using advanced driver assistancesystems
2. The resolution of challenges to efficient transport through a movement support information
platform
3. The innovation of multimode transport to support mobility inside cities
4. The comprehensive management of road traffic
5. Increasing the efficiency of logistics
6. The optimization of energy use
7. The promotion of international cooperation
As shown in Fig. 9, the ITS World Congress of 2013 showcased ITS Green Safety. Figure 10 provides an overview of the basic shift toward automated driving, while Figure 11 illustrates the Green
Wave Project, one of the National Police Agency’s projects for FY 2014.
Due to space limitations the points above represent the general flow of ITS in Japan, see the following documents for more detailed information. See Reference 4 for the overall flow. See Reference 10 for
information concerning the fundamental technologies, V2V and V2I information sharing (Connected
Vehicles). As for information concerning positioning, the combination of GPS,11) gyros, dead reckoning,
map matching, and other such methods alongside Wi-Fi access points,12) cellular base stations, and the

58｜Theory

platforms using those technologies have a variety of error-causing factors.13) Please refer to the indicatedreferences for additional information, or see References 6, 14, 15, and 16 for information regarding

Figure 9. ITS Green Safety Showcases4)

Crash safety
Autonomous(Built-in to
vehicle)Seat belts
Airbags
Vehicle bodystructure foroccupant
protection

Preventive safetyand driving assistance
Collision mitigation
braking
Vehicle-to-vehicle
distance and speed
control
Lane keeping control

Already commercialized/In dissemination stage
Provision of information/Warnings
Cooperative(Road-to-car/
Car-to-car)

Advanced Driver
Assistance
Vertical andhorizontal control
Vehicle groupcontrol
Convoys

Fully automateddriving

Obstacle ahead
Lane merge support
Dynamic route guidanceAreas with a broader sense of automated driving
Figure 10. The basic shift toward automated driving4)

Chapter 5: Intelligent Transport Systems｜59

Early removal of footfrom accelerator

Speed

Through-intersection
support

Provision of signal informationfrom optical beacons
Soft braking

Position
No system

Speed

Provision of travelingspeed information

SystemIntersection stop
support

Position
No system

SystemFigure 11. Examples of government ITS-related projects in FY 20144)(Source: National Police Agency)

automated driving from a variety of conceptual angles. Furthermore, although these may cover slightly
different topics, see Reference 17 for information on location-based services from basics to practicalapplications, Reference 18 for electrical vehicle diffusion scenarios, and Reference 19 for design theoryof new traffic systems.
An ITS is a sufficiently large-scale system to be referred to as a “system of systems” as describedabove, and looking at the system as a whole—from the fundamental technologies, to the system technologies, and ultimately to the services provided—we see it is in close contact with the real world, as avery wide ranging subject with a deep hierarchy. At its base exists a collection of vehicles and pedestrians, moving entities on the land, sea, and air, as well as positioning and information and communication. Furthermore, the actual concrete measures taken for positioning and information and communication sub-platforms suitable for mobile use will change with the times. In the past few years, asmartphone sensing sub-platform has been added, and dramatic changes have happened. It is necessary
to cultivate the technologies that ITS use into the fundamental and system technologies that these formsof mobility require in order to help improve safety, enhance efficiency, reduce environmental load, boost
convenience, and create more enjoyment through automated driving and big data processing. We need
to become familiar with each individual technical field, and create a system that contributes to society
through the mobility of people and things. To tackle such a wide breadth and such deep layers, readers
are encouraged to deepen their knowledge on the fundamental and system technologies through thereferences provided in this chapter.
As for the future of ITS, it is necessary to provide ITS suitable for each region and promote therealization of a next-generation mobility society based on changes in social and technologicalconditions.

60｜Theory

References
1) Ministry of Land, Infrastructure, Transport and Tourism. “ITS yogo shu” [ITS glossary]. Accessed November 6, 2014. http://
www.mlit.go.jp/road/ITS/j-html/topindex/topindex_g02_4.html. (in Japanese)
2) ITS Japan. “About ITS.” Accessed November 6, 2014. http://www.its-jp.org/english/about_e/.
3) European Commission. 1995. “Towards an intelligent transport system.” Community Research and Development Information
Service. Accessed November 6, 2014. http://cordis.europa.eu/news/rcn/3704_en.html.
4) ITS Japan. 2014. Nihon no ITS: ITS nenji repoto 2014 nen ban [Japan’ ITS: ITS annual report 2014]. ITS Japan. (in Japanese)
5) Tsugawa, Sadayuki. 1999. “Communication Systems in the Intelligent Transport Systems”. The transactions of the Institute ofElectronics, Information and Communication Engineers B J82-B (11): 1958–1965. (in Japanese)
6) Tsugawa, Sadayuki. 2013. “Survey on Automated Driving Systems.” IATSS Review Vol. 37, No. 3: 199–207. (in Japanese)
7) Japan Automobile Manufacturers Association, Inc. 2000. “ITS jitsugen no tame no sekkeizu: shisutemu akitekucha sakutei”[Plan to realize ITS: Drawing up a system architecture]. JAMAGAZINE, February. Accessed November 6, 2014. http://www.
jama.or.jp/lib/jamagazine/200002/07.html. (in Japanese)
8) Hasegawa, Takaaki. 2005. “On systematization of the ITS field.” Journal of Institute of Electronics, Information and Communication Engineers Vol. 104, No. 762 (ITS2004 89–97): 47–52. (in Japanese)
9) Honda Motor Co., Ltd. 2011. “Great East Japan Earthquake Traffic Information Maps Based on Honda Internavi Data Win
2011 Good Design Grand Award.” Honda Media Website, November 9. Accessed November 6, 2014. http://www.hondanews.
info/news/en/auto/4111109eng.
10) Ning, Lu, et al. 2014. “Connected Vehicles: Solutions and Challenges.” IEEE Internet of Things Journal Vol. 1, No. 4: 289–99.
11) Kubo, Nobuaki. 2010. “Dai 5 sho: GPS ni yoru sokuteichi to gosa yoin” [Chapter 5: measured values by GPS and error factors]. Paper presented at the tutorial session for the Institute of Positioning, Navigation and Timing of Japan, April 22.
Accessed November 6, 2014. http://www.denshi.e.kaiyodai.ac.jp/jp/assets/files/pdf/content/201004.pdf. (in Japanese)
12) Ito, Seigo, and Nobuo Kawaguchi. 2006. “Wireless LAN Based Hybrid Positioning System Using Bayesian Inference andAccess Point Selection.” IEEJ Transactions on Electronics, Information and Systems Vol. 126, No. 10. (in Japanese)
13) Hasegawa, Takaaki, Tetsuya Manabe, Katasuharu Hosoe, and Kazuo Mizuno. 2014. “Positioning Social Infrastructures fromthe Viewpoint of System Innovation: Applications and Smartphone Positioning Using GPS/Wi-Fi/BS.” IEICE Technical
Report (ITS 2013-76): 69–78. (in Japanese)
14) National Highway Traffic Safety Administration. 2013. “Preliminary Statement of Policy Concerning Automated Vehicles.”Press Releases, May 30. Accessed November 11, 2014. http://www.nhtsa.gov/staticfiles/rulemaking/pdf/Automated_Vehicles_Policy.pdf.
15) Furukawa, Osamu, et al. 2014. Jidosha oto pairotto kaihatsu saizensen: yoso gijutsu kaihatsu kara shakai infura seibi made[Frontline development of autopilot systems for automobiles: From underlying technology development to social infrastructure development]. NTS. (in Japanese)
16) Petit, J., and S. E. Shladover. 2014. “Potential Cyberattacks on Automated Vehicles.” IEEE Transactions on Intelligent Transportation Systems. http://dx.doi.org/10.1109/TITS.2014.2342271.
17) Küpper, Axel. 2005. Location-based Services: Fundamentals and Operation. Wiley.
18) Hasegawa, Takaaki. 2010. “Diffusion of Electric Vehicles and Novel Social Infrastructure from the Viewpoint of Systems
Innovation Theory.” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E93-A, No.
4: 672–678.
19) Hasegawa, Takaaki. 2013. “A Design Theory for New Transport Systems.” IATSS Review Vol. 37, No. 3: 224–232. Accessed
November 6, 2014. http://www.iatss.or.jp/common/pdf/publication/iatss-review/37-3-09.pdf. (in Japanese)
Practical application projects for reference
Practical application of a public involvement-type system for planning and evaluating road traffic safety measures: 160–163

Chapter

6

The image of
automobile safety
6.1

Changes in traffic accident statistics and safety measures

Chapter 6 considers the issue of automobiles in road traffic, reflecting on the history of safety improvement technology initiatives and clarifying the image of safety that serves as the end goal. To begin, we
reexamine the traffic accident statistics, which form the background for this issue.
Figure 11) shows annual changes in the number of traffic accidents in Japan. Looking at the longterm trend of traffic fatalities from 1951 to 2013, there are two noticeable peaks. These increases anddecreases are closely associated with the growth and social situation of the traffic society. The rapid(Persons, cases)
1,200,000(Persons)
20,0001,183,616 (2004)
981,096 (1970)
16,765 (1970)

1,000,000

781,494(2013)

952,709 (2004)

800,000

629,021 (2013)

600,000

400,000

200,000

596,282 (1979)

4,695(1952)

8,466 (1979)

6,277 (2012)
5,152 (2013)

4,429 (1951)

0
1951

10,0005,000

Road traffic accidents
Road traffic fatalities (within 24 h)

Road traffic injures
Road traffic fatalities (within 30 d)

4,373Road traffic fatalities (statistics from
the Ministry of Health, Labour and Welfare) (2013)

1966

1981

1996

31,274 (1951)
1956

1961

1971

1976

1986

1991

2001

2006

Road traffic fatalities

Road traffic accidents and injuries

15,0002013

0Note 1: Based on documents issued by the National Police Agency.
Note 2: Accidents involving property damage are not included in the number of cases after 1966. Okinawa Prefecture was not included in the survey until 1971.
Note 3: According to Article 2, Paragraph 1, Item 1 of the Road Traffic Act, “24-h fatalities” are persons who died within 24 h of a road traffic accident such as those involving automobiles, trains, orother vehicles.
Note 4: “Thirty-day fatalities” are persons who died within 30 days of a traffic accident (inclusive of 24-h fatalities).
Note 5: Fatalities in the statistics of the Ministry of Health, Labour and Welfare were provided by the National Police Agency based on the vital statistics collected by the Ministry of Health, Labourand Welfare. The number represents fatalities due to traffic accidents in the reference year and excludes persons who died after more than 1 year or due to accident-related aftereffects.
Before 1995, all automobile accidents are included, but the number for years later than 1995 is calculated by subtracting the number of fatalities due to non-road traffic accidents from thenumber of fatalities due to traffic accidents on land.

Figure 1. Number of traffic accidents, fatalities, and injuries on Japanese roads1)

62｜Theory

increase that begins in the 1950’s and culminates in a peak of 16,765 deaths (within 24 hours of accident) and 981,096 injuries in 1970 is what is informally called “Traffic War I.” Factor analysis of the situation indicates that it is the result of insufficient road maintenance, improvements, and traffic safety
facilities for the increased traffic loads caused by a rapid increase in private four-wheeled automobile
ownership. Other contributing factors include the change in consciousness of traffic participants notkeeping up with the rapid changes in the traffic society as well as insufficient technologies for ensuring
the safety of vehicles.
For this reason, the Traffic Safety Policies Basic Act was enacted in 1970 to promote traffic safetymeasures throughout the country. To account for the slow pace of changes in consciousness by traffic
participants, countermeasures at the time promoted vehicle–pedestrian separation, such as through thecreation of footbridges in addition to crosswalks and traffic signals, and through creation of guardrails(see Reference 2 for details of traffic facilities at the time). Automobile safety features such as those in
the Experimental Safety Vehicle, as will be discussed later, began to be considered, and beginning in
April 1969, driver’s seat safety belts became required in all domestically manufactured passenger vehicles. The requirement for safety belts would later be extended to passenger seats, and then to rear seats.
As a result of these measures, the number of fatalities trended downward until 1979 from its 1970 peak.
Following that, further increases in the number of privately owned automobiles and of driver’s
license holders resulted in a corresponding increase in automobile-kilometers travelled, creating a second upward trend in traffic accidents. There was a particularly noticeable increase in automobilekilometers travelled over the five-year period of economic prosperity beginning in 1986. Figure 2 shows
the results, with the number of passenger vehicle accident fatalities1) once again surpassing the 10,000(Persons)
6,000
Driving an automobile

Riding a motorcycle

Riding a motorized bicycle

Riding a bicycle

Walking

5,000

4,000

3,000

2,000
1,584 (36.2)
1,415 (32.4)
1,000
600 (13.7)
465 (10.6)
295 (6.7)

0
1979

1984

1989

1994

1999

2004

2009

Note 1: Based on documents provided by the National Police Agency (“Other” is not shown).
Note 2: Number in parentheses indicates the percentage of all injuries for that mode of transportation.

Figure 2. Changes in the number of traffic accident fatalities by mode of transport1)

2013

Chapter 6: The image of automobile safety｜63(within 24 hours) mark. This period is referred to as “Traffic War II.”To address this and reduce the number of passenger vehicle fatalities, automobile safety measures
such as anti-lock braking systems and airbags were promoted and became more common (Fig. 3 3)). In
1992, driver and passenger seatbelt usage in general road driving was made mandatory, and increased
seatbelt usage rates along with improvements to emergency care systems had the effect of decreasing
accident fatality rates (within 24 hours) following the peak in 1993 (Fig. 11)). Note, however, that in contrast to the situation in the 1970s, the number of traffic accidents and injuries continued to increase for10 years after the peak in 1993. This is because improvements to automobile safety features and emergency care systems lowered the fatality rates of serious accidents, meaning that those who would havedied in the 1970s setting were instead only injured.
Beginning in 2004, there has been a further reduction in the number of traffic fatalities alongside a
reduced number of traffic accidents, due to a number of factors including the dissemination of vehicle
safety technologies such as collision mitigation braking systems and skid prevention devices, promotionof automotive development through public evaluation of collision safety performance by car assessment
programs, increased penalties for drunken driving, increased rates of seatbelt usage, improvements indriver courtesy such as reduced speeding rates, and a reduced number of automobile-kilometers driven.
As of 2013, the number of annual traffic accidents is holding steady at approximately 600,000.
Number of passenger cars produced
Airbags
ABS

100%

Changes in passenger car safety measures (airbags/ABS)(Millions of cars)

6
5

60%

4

40%

3

20%

2

0%

4.53

5.06

4.96

4.46

4.54

4.58

4.46

4.47

4.43

4.57

4.66

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

Passenger cars produced

Installation rate relative tototal number of new vehicles produced80%1Note: Numbers were based on documents issued by the Japan Automobile Manufacturers Association.

Figure 3. Changes in passenger car safety measures (airbags/ABS)3)

The increasingly aging society in Japan of recent years has resulted in changes in traffic accident
trends. Since 2008 in particular, there has been a reversal in the number of pedestrian and automobile
passenger fatalities (Fig. 2). Examining the number of traffic accident fatality rates by conditions and age(Fig. 41)), one can see a remarkable increase in the ratio of deaths of age 65 and older pedestrians in accidents involving automobiles. Older people now have higher driver’s license possession rates, resulting ina trend of increased traffic fatalities involving elderly (age 75 or older) drivers.4)
Given these trends in traffic accidents of recent years, the 9th Traffic Safety Basic Plan of the Cabinet Office places a high emphasis on preserving the safety of pedestrians and cyclists along residential
roads, the primary living environment for the elderly.5) Recent automotive safety features to accommodate these changes include alterations to vehicle nose shapes and pop-up hood systems as well as other64｜Theory

vehicle body structural modifications for the reduction of

1,200 persons

1,000 persons

injury in the event of a pedestrian collision. Low-speed

800 persons

collision avoidance braking
systems that can reduce theseverity of impact with pedestrians and cyclists are also
increasingly being deployed.
Automotive safety technology development is thus
proceeding based on traffic
accident factor analysis, and

600 persons

400 persons≥65 years
60–64 years
50–59 years
40–49 years
30–39 years
25–29 years
16–24 years≤15 years

Driving an automobile
Riding a motorcycle
Riding a motorized bicycle
Riding a bicycle
Walking

200 persons

Rid

Wa
lk

Rid
ing

ing

ing

ab

icyc

le

ing

am

0 person

Dri

Rid

oto

vin

am

ga

rize

oto

db

na

rcy

cle

uto

mo

bile

icyc

le

Figure 4. Number of traffic fatalities by mode of transportation and age group1)

development and deploymentof these technologies are helping to reduce the number of traffic accidents. In the next section we willtake a closer look at trends in safety technology development over each era.

6.2

History and trends of automobile safety technology development

6.2.1 The dawn of safety measures: The ESV
As discussed above, the 1960s was an era of rapid motorization, not only in Japan but also in many
countries throughout the world, and around this time traffic safety attracted increased attention. To
improve the state of traffic safety, in 1970 the National Highway Traffic Safety Administration of the U.S.
Department of Transportation proposed development of the ESV, a test vehicle incorporating state-ofthe-art car safety technology. With the goal of reducing vehicle occupant fatalities, the ESV would target
technological advances for protecting occupants and aiding danger avoidance by drivers. In the U.S. at
the time, 60% of traffic fatalities were of passengers, so the U.S. plan may have been aimed at reducing
these numbers through passenger protection in the event of collisions.6)
In November 1970 the governments of the United States, Japan, and then West Germany exchanged
an agreement to implement the plan, bringing Japan into the project. At the time, the U.S. planned forstandards based on a vehicle weight of approximately 1800 kg. In Japan, however, a special committee in1971 considered and determined separate specifications for small vehicles—a 1150-kg four-seat vehicle
and a lighter 900-kg two-seat vehicle—and put out a call for developers. The Japanese standards aimed
to include a survival space in which occupants could expect to survive a head-on or rear-end collision at
speeds of up to 80 km/h, and included other preventative safety features for accident avoidance. Anotherfeature of the Japanese standards is that they called for adherence to both the Japanese Road Trucking
Vehicles Act and to the U.S. Federal Motor Vehicle Safety Standards.
The following presents specific examples of some of the safety technologies developed as part of theChapter 6: The image of automobile safety｜65

ESV program.
One such advance was improvements to vehicle construction designed for absorbing energy infrontal impacts of up to 80 km/h. These include the adoption of impact energy-absorbing frames andpillars and side beams designed to preserve a survival space for passengers.7) To aid in calculating these
new frame designs, engineers in the U.S. used NASTRAN, a finite element method application developed as part of NASA’s Apollo Program and released free of charge thereafter for private technology
transfer. It is notable that the techniques used for body rigidity and similar calculations today got theirstart in this early application for automobiles.
Another advance resulting from the ESV program was airbags. There had been previous proposals
for collision detection technologies coupled with safety cushioning, but none had yet been realized. At
the same time as the ESV program, proposals for the mandatory use of seatbelts were being debated,which increased demands for a passive restraint system that could mitigate the force of collisions without the use of seatbelts. This provided a reason for airbags to be considered as part of the ESV program.
This led to General Motors bringing to market the world’s first mass-produced automobile equippedwith an airbag system.
There were also advances toward better accident avoidance, such as an anti-skid braking system(now called anti-lock braking), and sideslip-limiting features (now called electronic stability control).
These two systems together significantly improve vehicle stability when braking.
Participating companies developed and implemented performance evaluations on several test vehicles through the ESV program, which was generally complete by the time of its 5th International Conference in 1974. The program was successful in its goals of actually producing a test vehicle that included
the state-of-the-art technology of the time, but these efforts were undertaken without consideration of⑫ ② ㉗ ⑦
⑥

⑪⑭⑬

③⑨
⑩ ⑧

⑱⑲ ⑳
⑰

①⑮

㉑

⑯
㉕ ㉓

㉔

⑭
㉖

㉒
④
⑧ ⑨⑤

⑪

① Centralized warning and action indicator system ② Dual-sided turn signals ③ Anti-lock disk brake system④ Anti-lock drum brake system ⑤ Electronic control unit for anti-lock brake system ⑥ Anti-lock brake actuator ⑦ Vacuum booster⑧ Safe tires ⑨ Tire inner pressure monitoring system ⑩ Automatic transmission ⑪ Bumper with urethane pad⑫ Urethane pad ⑬ Energy-absorbing frame structure ⑭ EAU ⑮ Impactless steering wheel and column⑯ Webclamp emergency locking retractor ⑰ Energy-absorbing belt ⑱ Door reinforced with beams ⑲ Energy-absorbing side pads
⑳ Shoulder pads ㉑ Retractable shoulder pads ㉒ Current-blocker ㉓ Fuel tank ㉔ Emergency exit ㉕ Emergency exit lever㉖ Emergency exit lock ㉗ CVCC engine

Figure 5. Experimental safety vehicle (structural diagram of the Honda ESV)9)

66｜Theory

manufacturability or costs. The Research Safety Vehicle Program based on consumption trends andmass productivity took over where the ESV left off, but now focuses its consideration on developing
issues such as energy shortage and environmental concerns.8) The numerous safety features that began
as part of the ESV program and are now implemented in actual production vehicles (Fig. 59)) are a testament to the significant role it played in the development of new safety-related technologies.
6.2.2 The Advanced Safety Vehicle
Figure 6 shows trends from 1970–1990 for Japanese, U.S., and European projects related to intelligent
transport systems (ITS). From this figure, one can see that there were various Ministry-sponsored projects now linked to current ITS that began in the late-1980s Japan, encompassing the Traffic War II
period.
Among these projects, the one relating to vehicles is the Advanced Safety Vehicle (ASV) program,which began from the Japanese Land, Infrastructure and Transportation Ministry. The project has beenongoing since 1991, and as of 2014 is now in its fifth five-year plan. The project is guided by a review
committee that includes representatives from among academic experts, affiliated organizations, relevant
ministries and agencies, and fourteen automobile and motorcycle manufacturers. Table 1 shows an overview of the ASV program’s promotional plan for each period.
The ASV program aims at preventing accidents and reducing damage due to collisions throughimplementation of electronic control technologies that were rapidly developing in the 1980s, and furthermore by establishing the technological foundation for vehicle-side ITS features. ASV vehicles therefore feature a variety of sensors (Fig. 7) and control mechanisms.
The program’s first period (1991–1995) was largely focused on technological considerations for
Phase 1

EuropePhase 2

ALI

Phase 3

MOBILITY 2000

ERGS

‘70
Japan

‘80
CACS
(Ministry ofInternational
Trade andIndustry)

‘90

‘91

TELEMATICSDRIVEⅡDRIVEⅠThe UnitedStatesPROMOTEPROMETHEUS

ITS (America)

IVHS

‘92

‘93

‘94

‘95

‘96

RACS (Ministry of Construction)
AMITICS (National Police Agency)

VICS (Ministry of Posts and Telecommunications)

ARTS (Ministry of Construction)

ITS Japan

SSVS (Ministry of International Trade and Industry)
ASV (Ministry of Transport)
UTMS (National Police Agency)

Figure 6. Early phases of the ITS-related projects (organization names are for the indicated year)

Chapter 6: The image of automobile safety｜67

Table 1. Outline of timeline for ASV promotion10)
Phase 1

Phase 2Phase 3Phase 4Phase 51991–1995

1996–2000

2001–2005

2006–20102011–2015•Provingtechnological
feasibility•Researchanddevelopment
forcommercialization•Investigationforpromotion
andmarketing•Developmentofadditional
technologies•Full-scalemarketing•Partialcommercializationofthecommunication-based
safetysystem•Dramaticadvancement•Singlevehicle
(self-sensingtype)•Singlevehicle
(self-sensingtype)•Vehicle-infrastructure
cooperation•Singlevehicle(self-sensingtype)•Vehicle-infrastructure
cooperation•Singlevehicle(self-sensingtype)•Linkswithothervehicles•Vehicle-infrastructure
cooperation•Dramaticadvancementin
commercializedASV
technology•Next-generationcommunication-baseddriving•Developmentandmarketing
ofthesupportsystem

Computer

Recognizes a risk, judges it from sensor information and transmits it to a control device.

Sensors

Recognizes driving environment and vehicle conditions.

Control systems Provide information and warning based on computer information and assist driver’s operation.

Active headrest & motor
seatbelt pretensioner
Driver surveillance camera

Infrared camera

Communication system

Infrared sensor

Periphery surveillance camera, –Message board system

Heads-up display
Vehicle position sensor

Speed and acceleration sensors– , –Hydraulic pressure sensor

Side/rear obstacle sensor,

Steering angle sensor– , ,Passenger detection sensor

Infrared sensor
Vehicle body for mitigating pedestrian injury
and airbag system for pedestrian protection

Brake control device– ,Steering control device
Headway distance and obstacle sensors,, ,Advanced front-lighting system

Information display monitor and audio speaker
Navigation system,

ComputerThrottle control device,,

Major systems developedin the ASV-2① Forward obstacle collision
prevention support system② Curve overshooting prevention
support system③ Full speed range adaptive
cruise control system withbrake control④ Lane departure prevention
support system⑤ Lane keeping assistancesystem
⑥ Blind-spot obstacle collision
prevention support system⑦ Advanced front-lighting system⑧ Neck injury mitigation system
for rear-end collision⑨ Vehicle body for mitigatingpedestrian injury and airbag
system for pedestrian
protection⑩ Drowsiness warning system⑪ Seatbelt warning system for all
passengers⑫ Rear and side information
provider⑬ Emergency braking advisorysystem for the following
vehicle’s driver⑭ Nighttime pedestrian
monitoring system

Figure 7. Schematic of ASV11)

passenger cars, but starting with the second period (1996–2000) extended to large trucks and motorcycles. Another characteristic of the second period is that it marks the point when international ITS
research began to take off. In the ministry publication Comprehensive Plan for Intelligent Transport Systems, published in July 1996, the ASV was promoted as a part of “support for safe driving.” Cooperation
between the vehicle and the road infrastructure was also considered, and in October 2000 cooperative
verification experiments were performed at the Ministry of Land, Infrastructure and Transport’s Public
Works’ Research Institute (formerly the Ministry of Construction’s Public Works Research Institute) in
Tsukuba, Ibaraki Prefecture. These experiments aimed to test driver acceptance and the appropriateness68｜Theory

Action taken by the system

Driver behavior① Communications

The system should provide driving assistance that meetsthe thoughts and intentions of the driver.

② Safe driving stable activation

The system should provide driving assistant to promote driving safety.

③ Confirmation of actions (monitoring required)
The driver should be able to check the actions of the system.

④ No overconfidence

The system should be designed not to make the driveroverconfident in the system’s abilities.

⑤ Can be overridden by the driver

The driver should be able to manually override actions
taken by the system⑥ Smooth transition

Does not worsen
safety.
Conditions are suitable
for social acceptanceof the system.

The system should smoothly transfer controlof the vehicle back to the driver when its range of ability
is exceeded.

Society
Figure 8. Flow of driving assistance12)of road infrastructure for seven services for integration with an advanced cruise-assist highway system:
forward obstacle collision prevention, curve approach risk prevention, lane departure prevention, intersection collision prevention, right turn collision prevention, crosswalk pedestrian collision prevention,and vehicle spacing maintenance through use of road surface information.
The third period (2001–2005) was largely concerned with advancing promotion of the ASV. At thistime, the “Design principles of ASV” that were developed in the second period were concretely compiled into “concepts for driving assistance” (Fig. 812)). With regards to “retaining driver acceptance,” forexample, it is important that the driver be able to confirm system operations. A “principle for driverassistance” clarifies that it is the driver who must be the central component of safe driving, and that ASV
technologies are intended only to serve a sideline support role. This principle requires that in actualized
devices there must be a driver-operable switch that enables operation of the assistance system, and thateven when the system is enabled, it must be possible for the driver to forcefully intervene. To ensure system integrity, this principle for driver assistance will need to be incorporated as part of the legal preparations for actualization of the automatic driving systems that are currently under development.
Basic system designs for driving support systems that incorporate communications were taken up
in the fourth period (2006–2010), and are being used in vehicle surroundings recognition support services that use vehicle-to-vehicle communications for accident avoidance, and are expected to reduce thenumber of accidents at intersections and during turns. Also under consideration are accident prediction
applications using accident analysis to monitor driver state in commercial vehicles to prevent the health-Chapter 6: The image of automobile safety｜69

related accidents that are a social problem in the current age.
6.2.3 The future of the ITS concept
As described in the previous section, automotive technologies using electronics and communications
technologies for reducing accidents and improving safety have an important position in the ITS field.
The ITS interim plan (2011–2015) created by ITS Japan in 2011 calls for a next-generation mobility system that integrates traffic networks, energy networks, and communications networks.13) Of particularnote is that as a result of the 2011 Great East Japan Earthquake, the report specifies the need for construction of an ITS-based information infrastructure that remains usable in times of disaster. Anotherdevelopment is that of systems combining ASV and communications technologies for vehicle-to-vehiclecommunications through multi-POP routing, for example, to realize information sharing related toother vehicles in the vicinity or road conditions ahead, thus ensuring the safety of entire groups insteadof just individual cars. Such advance sharing of information related to potential risks and dangers will
likely reduce the number of traffic accidents. The development of new support technologies for pedestrians, cyclists, and new forms of mobility will also help to compensate for the effects of driver inexperience and cognitive decline due to aging, helping to realize a transportation society through which all
members can safely move.14)
At the 20th ITS International Conference held in Tokyo in 2013, various companies gave demonstrations of their automatic driving systems, indicating that realization of these systems is now well supported at the government level.15) A summary roadmap clearly defines the driving support and automated operation systems presented in the previous section regarding ASV (Table 2), and strategies suchas unification of autonomous and cooperative systems are listed along with items of emphasis.
Table 2. Definition of driving safety support and automatic driving systems15)
Category
Information provided type

Automated type

Overview
Warning the driver, etc.
The vehicle performs acceleration, steering, orLevel 1: Single operation
braking.
The vehicle performs one or two acceleration,
Level 2: Complex systemsteering, and braking operations simultaneously.
The vehicle performs all acceleration, steering,
Level 3: Advanced systemand braking operations (emergency response:
driver).
Level 4: Fully automated driving The vehicle (not the driver) performs all
systemacceleration, steering, and braking operations.

Corresponding system
Driving safety support system

Semi-automateddriving system

Automated driving
systemFully automated driving
systemReferences
1) Cabinet Office. 2014. Heisei 26 nenban kotsu anzen hakusho [White paper on traffic safety in Japan 2014]. Accessed December 10, 2014. http://www8.cao.go.jp/koutu/taisaku/h26kou_haku/zenbun/index.html. (in Japanese)2) Fukuda, Atsushi et al. 2011. “Kotsu senso eno torikumi: tojo koku ni koken shiuru nihon no keiken to chiken” [Managing
traffic war: Japan’s experience and knowledge that can contribute to solving traffic issues in developing countries]. Heisei 22
nendo kenkyu chosa hokokusho [Research report 2012]. International Association of Traffic and Safety Sciences. (inJapanese)

70｜Theory3) The National Police Agency, Traffic Bureau. 2007. Heisei 18 nen chu no kotsu shibojiko no tokucho oyobi doro kotsuho ihan
torishimari jokyo ni tsuite [Characteristics of fatal traffic accidents and effectiveness of traffic violation control]. (in Japanese)
4) Institute for Traffic Accident Research and Data Analysis. 2012. “Kotsu tokei heisei 24 nen ban.” [Statistics for traffic 2012].
Accessed December 10, 2014. http://www.itarda.or.jp/. (in Japanese)5) Cabinet Office. 2011. “Dai 9 ji kotsu anzen kihon keikaku.” [Traffic safety basic plan 9]. Accessed December 10, 2014. http://
www8.cao.go.jp/koutu/kihon/keikaku9/. (in Japanese)6) Okami, Yoshiro. 1976. “Safety and the ESV Program.” IATSS Review Vol. 2, No. 2: 132–140. (in Japanese)7) Toyota Motor Corporation. “Toyota jidosha 75 nenshi” [75 years of Toyota]. Accessed December 10, 2014. http://www.
toyota.co.jp/jpn/company/history/75years/text/index.html. (in Japanese)
8) Sano, Shoichi. 1979. “ESV Program and the Perspective of Study on Automobile Safety.” IATSS Review Vol. 5, No. 4: 300–
305. (in Japanese)9) Society of Automotive Engineers of Japan, ed. 2009. Jidosha no hyakka jiten [Encyclopedia of automobiles]. Maruzen Publishing. (in Japanese)10) Ministry of Land, Infrastructure, Transport and Tourism. ASV suishin keikaku ni tsuite [About ASV Promotion Program].
Accessed December 10, 2014. http://www.mlit.go.jp/jidosha/anzen/01asv/aboutasv.html. (in Japanese)11) Ministry of Land, Infrastructure, Transport and Tourism. 2002. Dai 3ki ASV suishin keikaku panfuretto [ASV Promotion
Program pamphlet (Third period)]. (in Japanese)12) Ministry of Land, Infrastructure, Transport and Tourism. 2011. Dai 5ki ASV suishin keikaku panfuretto [ASV Promotion
Program pamphlet (Fifth period)]. (in Japanese)
13) ITS Japan. 2011. ITS Shin chuki keikaku (2011–2015 nen) no sakutei [Development of a new midterm ITS plan 2011–2015].
Accessed December 10, 2014. http://www.its-jp.org/katsudou_old/katudou170/. (in Japanese)
14) ITS Japan. 2013. ITS niyoru mirai sozo no teigen: daredemo dokodemo kaiteki ni ido dekiru shakai no jitsugen [Recommendations of the creation of the future by ITS: creating the society that provides everyone with access to any place with comfort].
Accessed December 10, 2014. http://www.its-jp.org/document/20131017/ITS-future-vision_j_131010.pdf. (in Japanese)
15) IT Strategic headquarters. 2014. Kanmin ITS koso/rodo mappu [Government and people ITS framework/roadmap]. (inJapanese)
Recommended Reading
1) Ministry of Land, Infrastructure, Transport and Tourism. “ASV ni kansuru kenkyu seika hokokusho” [Results of research on
ASV]. Accessed December 10, 2014. http://www.mlit.go.jp/jidosha/anzen/01asv/index.html. (in Japanese)2) Ministry of Land, Infrastructure, Transport and Tourism. 2001. “Senshin anzen jidosha (ASV) suishin keikaku (dai 2 ki) ni
kansuru hokokusho” [Report on promotion plan for advanced safety vehicles (2nd stage)]. Accessed December 10, 2014.
http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/asv2report.pdf. (in Japanese)3) Ministry of Land, Infrastructure, Transport and Tourism. 2006. “Senshin anzen jidosha (ASV) suishin keikaku hokokusho:
dai 3 ki ASV keikaku ni okeru katsudo seika ni tsuite” [Report on the promotion plan for advanced safety vehicles: results of
ASV promotion plan (3rd stage)]. Accessed December 10, 2014. http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/
asv3seikahoukokusyocorrection.pdf. (in Japanese)4) Ministry of Land, Infrastructure, Transport and Tourism. 2011. “Senshin anzen jidosha (ASV) suishin keikaku hokokusho:
dai 4 ki ASV keikaku ni okeru katsudo seika ni tsuite” [Report on the promotion plan for advanced safety vehicles: results of
ASV promotion plan (4th stage)]. Accessed December 10, 2014. http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/
asv4pamphlet_seika.pdf. (in Japanese)Chapter

7

Technologies forsafety improvement
7.1

Passenger vehicles

This section categorizes by features various technologies for realizing the safety image presented in
Chapter 6 and introduces the technologies with respect to each category of vehicle. We also describe theimplementation timing for the devices shown in Fig. 1, mainly for passenger vehicles.

Areas incorporating safety technologies
Range for reducing the number of deaths due to traffic accidents
Range for reducing the number of traffic accidents
Before accident

Immediately before
Collision prevention

Notification

SupportActive safety
Preventive
SafetyACC
LKA
AFS
Multiview camera

Damage reduction

Pre-collisionsafetyCMBS
E-pretensioner

After accident

Collision

RescueIntervention

Accident avoidance Pre-collision safety
ABS
TRC
ESC

During and immediately after

Automated Collision Notification System

Passive safety
Injury reduction

Damage mitigation

Collision safety body
Seatbelt/child seat
Airbag system
Pop-up hood
Active headrest

Emergency alert system
Energy-sensitive door unlock
systemFigure 1. Areas incorporating safety technologies

7.1.1 Active safety
As of 2013, there are approximately 600,000 automobile accidents in Japan per year, and there is ongoing
research and development and efforts to spread active safety technologies for preventing automobile
accidents through the use of electronics and control technologies.

72｜Theory(1) Visibility enhancement technologies
Today we are seeing the practical use of highluminosity discharge and LED headlights,
which can improve forward visibility at sunset, at nighttime, and during inclement
weather. There has also been increased implementation of adaptive front-lighting systems,
which measure steering angle and vehicle
speed to calculate the forward path of automobiles through turns in order to control thereflective mirrors of the headlight units, orienting them to better illuminate the path oftravel.

Figure 2. Intelligent night vision system enhancing visibility ofpedestrians1)

Indirect visibility is being improved aswell. Installation of multiple cameras onto the car body allows display on monitors of traffic lanes atintersections with poor visibility, displays of the vehicle size superimposed on a rear-view image of the
car when it is in reverse, and displays of the full area around the vehicle. Such fusions of video display
with graphic image processing technologies allows for visibility enhancements of what is happening all
around the vehicle.
Night vision systems to alert drivers of obstacles are also being developed (Fig. 21)). Shining infrared light in the direction of travel during nighttime driving allows use of infrared cameras that can visualize and emphasize pedestrians or road conditions that would otherwise be difficult for the driver to see
with the naked eye.
(2) Driving workload reduction technologies
While traditional cruise control systems maintain a constant speed on highways, adaptive cruise control(ACC) systems monitor conditions in front of the car by using millimeter-wave radar and stereographic
cameras, and automatically adjust travelling speed to maintain a constant distance from other vehicles.
ACC systems can be used not only to maintain speed on high-speed roadways, but also to provide proximity alerts and collision prevention in heavy traffic conditions on general use roads. Low-speed ACC
systems in particular can be used in conjunction with collision mitigation braking systems to avoid or
reduce low-speed collisions, and are looked to as a way of reducing the number of accidents at intersections, which account for the majority of traffic accidents.
Lane departure warning systems that use cameras and lane confirmation technologies are practical.
In addition, intelligent driver assistance systems are being combined with car navigation systems. Thesecan be used, for example, to notify or warn drivers of upcoming intersections at which a full stop is
required.

Chapter 7: Technologies for safety improvement｜73(3) Vehicle dynamic performance technologies
When turning a steering wheel, if tire rotation is locked, then sufficient lateral force cannot be generated
for yaw motion of the vehicle. For that reason almost all cars today have anti-lock braking systems (ABS)as standard equipment. ABS constantly monitors wheel rotation, and in cases where slippery road surfaces cause wheel locking during braking, briefly releases brake pressure to resolve the lock. By thenraising brake pressure in a manner that prevents re-locking, braking can be performed in a manner thatstill permits steering wheel operation.
Electronic stability control systems have been required as a standard feature on all new automobiles
since October 2012. These combine ABS with traction control systems, which prevent tire spinning during starts and acceleration, to provide active unified control of the force generated by each tire and thus
prevent or reduce wobble and sideslip of vehicles. Integrating such systems with electronic power steering and others has also been promoted, which allows for overall improvements to vehicle dynamic performance, realizing better danger and accident avoidance in emergencies.
7.1.2 Passive safety
This section introduces technologies for minimizing damage to humans in the event of an accident.
(1) Collision damage mitigation technologies
The impact that is transmitted to occupants in a collision depends on the vehicle’s momentum, which isthe product of its mass and velocity. In the case of an extremely rigid vehicle body, the impact is immediately transmitted to the occupants, increasing the likelihood of serious injury. Engine compartments
therefore have a “crumple zone” designed to deform and thereby absorb rather than transmit energy,
reducing the amount passed on to occupants. In current methods of frame design, the amount of frame
deformation in the time domain is calculated at the design stage, and design proceeds to ensure that the
impact force delivered to occupants does not exceed a given critical danger value.
In vehicle-on-vehicle collisions, differences in the form of the colliding automobiles can result in
impacts at different frame locations, sometimes significantly lowering the functioning of the crumple
zone. The frames of light motor vehicles and standard class passenger cars are thus now designed toretain some degree of compatibility so that in the event of a collision, the frame of each can function as
designed (Fig. 32)).
Another recent technology for reducing the impact to passengers during a collision is emergency
locking
retractor
seatbelts equippedwith pretensioners
and load limiters.
When a collision isdetected these seatbelts instantly retract
any slack, and thenFigure 3. Schematic diagram of crash-compatible car bodies2)

74｜Theory

the belt is fed out when a certain load is exceeded. Doing so can reduce injury to the chest.
Supplemental restraint system airbags have become standard equipment for both driver and passenger seats. In recent models collisions can be detected approximately 0.015 seconds after they occur.
By varying the airbag inflation rate according to the speed of impact and constantly changing the airbag
volume, passengers with various body types can be better protected. Side impact airbags that inflate in acurtain shape are also being increasingly deployed, and are effective toward reducing head and neckinjuries.
(2) Pedestrian injury mitigation technologies
As a way of reducing injury to pedestrians in the event of a collision, automobile bumpers, fenders, andhoods are now being designed with space beneath them and are being manufactured with easily dented
materials. Hood hinges are also being constructed so that when a strong force is applied to them theyfold so as to absorb energy. Protrusions are being eliminated from car bodies to the extents possible toremove locations where a human body might get caught in a collision; this is one of the reasons why
retractable headlights that pop up only when in use are no longer seen. Yet another safety feature ishoods that pop up at the moment a collision is detected, to produce a larger space beneath them.

7.2

Commercial vehicles

The forms of buses and large trucks are inherently different from those of passenger vehicles, due to theneed to retain space for passengers and cargo. These vehicles are also operated in different ways, and sohave unique safety features according to their characteristics.
Such vehicles are large, and truck beds or loaded cargo can create blind spots from the driver’s seat,particularly to the rear and sides.3) These blind spots are being eliminated through the use of multiple
mirrors as well as rear-facing cameras and sonar equipment that allow for confirmation of the status ofareas of poor visibility. In recent years there have been trials of making the lower portion of passenger
side door panel transparent, to improve side visibility.
Commercial vehicles remain in continuous operation for longer periods than do passenger vehicles, so equipment for monitoring driver attention is in practical use. As an example, certain systems use
cameras to monitor the direction that drivers are facing and the status of their eyes, to ensure they arepaying attention. Another system uses fuzzy logic to analyze the first 15 minutes of driving behavior,and from this can detect declines in driver attention from steering wheel operations and the like. In bothcases, when driver inattention is detected a warning is sounded and displayed. An alarm can also besounded when driver inattention is accompanied by weaving or failure to maintain lanes, and when thishappens multiple times in sequence accidents can be prevented by decreasing the timing before whichcollision damage mitigation braking is applied.4)
With regards to vehicle dynamic performance, heavy-duty vehicles generally weigh more than passenger vehicles, and large loads on trucks can raise their center of gravity. This makes it easier for trucks

Chapter 7: Technologies for safety improvement｜75

to roll over or spin out in turns, leading to accidents. Today, in order to reduce such accidents, electronicstability control systems are being used in heavy-duty vehicles, just like in passenger vehicles.
Approximately 50% of accidents involving commercial trucks are rear-end collisions, and on highways the ratio reaches as high as 72%.5) In an effort to reduce these accidents, implementation of collision mitigation braking systems is beginning to become mandatory for trucks. Trucks also tend to havea large clearance between their body and the road, leading to a submarine phenomenon at the time ofcollision with other categories of vehicles. Vehicle under-run protection devices are therefore currently
mandatory, increasing compatibility with other automobiles as in the case of passenger vehicles.
In the future, we can expect to see more commercial vehicles adopting technologies from the ITS
field, such as spacing maintenance systems (electronic horn system) using road-to-vehicle and vehicleto-vehicle communications devices for comprehending conditions in the vicinity of operation. Also,these are expected to reduce the number of accidents involving other vehicles and to allow the formation of lines of trucks that automatically follow leader trucks, reducing fatigue in long-distance truck
drivers.

7.3

Motorcycles

Motorcycles have two wheels, one in front of the other, and so must maintain balance at all times while
in operation. Control operations are also more direct, such as by the rider directly changing steering
angle or leaning the vehicle while in turns. There are some advanced systems that, for example, adjust
engine output according to the vehicle attitude to prevent rear-tire skidding, but direct intervention
through electronic stability control, such as that used in four-wheeled automobiles, is difficult.
One safety feature that accommodates these differences and is currently in practical use is an ABS
system that uses electronic controls to link the front and rear wheel brakes. Motorcycles have a higher
center of gravity than four-wheeled vehicles due to their shorter wheelbase and higher passenger-to-

braking. Fig. 4 shows the resulting
ideal braking force distribution
curve for a motorcycle. Unlike thecase in four-wheeled vehicles, whena motorcyclist applies sudden braking in excess of 0.5 G, the braking
force on the front wheel must be
increased and that on the rear wheel
decreased. Attempts to apply singleinput braking similar to that in

1000
Ideal brake force distribution
Rear-wheel braking force (N)vehicle mass ratio. This results in ahigher load transfer from the rear
wheel to the front wheel under

800
0.4

600
0.2

400

0.6
0.8

Rider + passenger
Braking decelerationof 1.0 G

200
Rider only
0

0

500

1000
1500
2000
2500
Front-wheel braking force (N)3000

Figure 4. Ideal brake force distribution for motorcycle

3500

76｜Theory

automobiles result in complex apparatuses for rearbrake fluid pressure reduction, which is impractical forpractical application given
the motorcycle’s limited
mounting space. Most motorcycles thus have separate
front and rear brake systems

Power
unit
Valve
unit

Power
unit
ECU

Valve
unit

Front brake

Rear brake
Foot pedal
Hand lever

Figure 5. Diagram of electronically controlled combined ABS6)

that riders themselves must operate independently in attempts to reproduce the ideal braking force distribution curve.
Electronic control of front and rear brakes coordinated through a by-wire can convert rider input
to electronic signals, allowing computers to control both braking and the fine-grained activation of theABS. This electronic control allows elimination of the ABS-dedicated equipment that was previously
mounted on moving parts of the suspension, allowing use of standard parts.6)
Another new technology is dual-clutch transmissions which reduce the shock caused by gearchanges. This allows riders a larger margin of operation, and is expected to reduce the risk of accidents.7)
Regarding passive safety, due to motorcycles’ riding form and much smaller machine size, it is difficult to provide crumple zones like those seen in four-wheeled vehicles. However, through developmentof the ASV, some larger motorcycles now feature airbags. These airbags feature forms, sizes, and inflation methods particular to motorcycles, designed to accommodate the non-restrained seating of arider.8)
In recent years there riding
Advanced Safety Vehicle and Driving Safety Support Systems (ASV/DSSS) tojackets equipped with internallyprevent left-turn accidents
stored airbags have also been [Purpose] To prevent left-turn accidents, information on hard-to-see vehicles is provided some distance backduring left turns at an intersection with traffic signals.
developed. These airbags auto- [Expected benefits] Reduction in the number of left-turn accidents (accident prevention through provision of
information regarding blind spot)
matically inflate when the rider
becomes separated from the
motorcycle due to a collision or
rollover.
Motorcyclists on city streets
frequently travel between lanes

Motorcycle present
Please turn left
carefully

Pay attention to motorcycles
Antenna

Beaconor along road shoulders to avoid
traffic. As ITS becomes morewidespread, road-to-vehicle andvehicle-to-vehicle communications devices like those describedfor automobiles are expected todecrease the number of accidents

Vehicle detection
cameraControl device

Figure 6. Vehicle-infrastructure cooperation under the intelligent transportsystem9)

Chapter 7: Technologies for safety improvement｜77

at intersections or involving cars turning in front of motorcycles, as such devices can alert other vehicles
to their presence (Fig. 69)).

7.4

Other safety technologies

There have also been significant
changes in tire technology. Runflat tires (Fig. 7) have reinforced
sidewalls that allow travel for somedistance following a puncture. This
allows vehicles to be operated

Sidewall-reinforcing rubber
Conventional tireRun-flat tire

Tire shape withnormal inner pressure

Tire shape with
0 kPa pressure

Tire shape with
0 kPa pressure
Sidewall-reinforcing rubber(representative image)without carrying a spare, reducing
Structure of run-flat tire
Mechanism of run-flat tires
with a reinforced sidewallwith a reinforced sidewall
vehicle weight and thus fuelconsumption.
Figure 7. Structure of a run-flat tire10)
Vehicle body component
materials too are changing. While their use remains limited at present, we are starting to see the use ofcarbon fiber-reinforced plastic, in addition to the traditional ultra-tensile steel in consumer vehicles.
This is expected to further reduce vehicle weight, improving running characteristics and decreasing fuelconsumption. As body designs advance, assuming the increased use of such composite materials, freedom of design will allow increased safety over current mainstream body shapes.
Electric and hybrid vehicles are increasingly popular due to their environmentally friendly nature,
but vehicles operating under electric power make much less sound than do those with an engine drive.
This can result in pedestrians being unaware of their presence, increasing their involvement in accidents.
Some such vehicles now issue an electronic sound when operating in electric mode, alerting thosearound them to their presence.
Electric vehicles also containhigh voltage components, so
designs are now taking this inconsideration to prevent accidental electrocution in the eventof accidents.
As society continues to age,
the rise of a new category ofvehicles is becoming apparent:
ultra-compact mobility devices
with very small vehicle footprints
and high maneuverability (Fig.
811)). These vehicles generally

MC-β2,495mm

Light motor vehicle

3,395mm

Minivan

4,690mmFigure 8. Size comparison of ultra-compact mobility devices11)

78｜Theory

Non-Road Vehicles

On-Road Vehicles

For facility and sidewalk use

For on-road use

Rated output(electric vehicles)≤0.6 kWEngine capacity (internal
combustion engine vehicles)≤50 cc>50–≤660 cc>660 cc

Japanese Mopeds

Light motor vehicles

Small andstandard vehicles

As walking aid(no license required)・1 seating capacity
・≤6 km/h
・No safety inspection required ・Maximum loading capacity:
up to 30 kg
・Length: 1,200 mm
Width: 700 mm
・Length: 2,500 mm
Height: 1,090 mm
Width: 1,300 mm
Height: 2,000 mm
・No collision criteria applied・No safety inspection required
・Not for highway use

For use as a walking aid
and support>1 kW

Ultra-compact
mobility devices
・1–2 seating capacity
・Not for highway use

For use in daily living and for the transportation of small goods
Great for a small distance transport

・4 seating capacity
・Maximum loading capacity:
up to 350 kg
・Length: 3,400 mm
Width: 1,480 mm
Height: 2,000 mm
・Collision criteria applied
・Safety inspection required
・Not for highway use

Useful under various circumstances and situations,
including on highways

Figure 9. Ultra-compact mobility devices in comparison with conventional vehicles in Japan12)

allow only one or two occupants, and consume only about a sixth the energy of a standard vehicle (orabout half that of an electric vehicle). They are generally intended for local travel near the home, excursions
at tourist destinations or commercial areas, and small-scale delivery operations, but as they become more
popular, more of these vehicles will likely be mixed in with general traffic, and there will be a need to confirm that they are diﬀerentiated and supplied with sufficient running space (Fig. 912)).
As with motorcycles, these vehicles are very small, making it difficult to design them with crumple
zones. However, as they become more prevalent there will be an increasing need for developing compact, cost-effective collision prevention devices to reduce the number of accidents that they become
involved in.
References
1) Honda Motor Co., Ltd. 2004. “Honda Develops World’s First Intelligent Night Vision System Able to Detect Pedestrians andProvide Driver Cautions: Available on Legend model to be released in Fall 2004.” Honda Worldwide, August 24. Accessed
December 10, 2014. http://world.honda.com/news/2004/4040824_01/video/index.html.
2) Honda Motor Co., Ltd. 2014. “The crash-compatibility body: increasing overall safety for everyone on the road.” Honda
Worldwide. Accessed December 10, 2014. http://world.honda.com/automobile-technology/compatibility/
3) Japan Safe Driving Center. 2007. Ogata kamotsusha no anzen unten [Safe driving of large freight vehicles]. Accessed December 10, 2014. http://www.jsdc.or.jp/search/pdf/all/h18_3.pdf. (in Japanese)4) Mitsubishi Fuso Truck and Bus Corporation. 2008. “Dai 58 kai jidosha gijutsu kai sho de unten chui ryoku monita (MDASIII) ga gijutsu kaihatsu sho o jusho” [Mitsubishi’s Driver’s Attention monitoring system won the Technology Development
Award at the 58th Society of Automotive Engineers of Japan, Inc. award contest]. Accessed December 10, 2014. http://www.
mitsubishi-fuso.com/jp/news/news_content/080424/080424.html. (in Japanese)
5) Japan Trucking Association. 2014. Jigyo yo kamotsu jidosha no kotsu jiko no keiko to jiko jirei [Trends and examples of accidents involving large commercial freight vehicles]. Accessed December 10, 2014. http://www.jta.or.jp/member/
pf_kotsuanzen/jikojirei.pdf. (in Japanese)
6) Honda Motor Co., Ltd. 2014. “Taking super sport riding to a new level-world’s first Electronically Controlled Combined
ABS for super sport bikes.” Honda Worldwide. Accessed December 10, 2014. http://world.honda.com/motorcyclepicturebook/eCBS/.

Chapter 7: Technologies for safety improvement｜79

7) Honda Motor Co., Ltd. 2014. “Enjoy the performance of a manual transmission with the convenience of an automatic.
Honda introduces the world’s first dual-clutch transmission for use in a motorcycle.” Honda Worldwide. Accessed December
10, 2014. http://world.honda.com/motorcycle-picturebook/DCT/.
8) Honda Motor Co., Ltd. 2014. “The world’s first production motorcycle airbag system, designed to help lessen the severity of
injuries to the rider in a frontal collision.” Honda Worldwide. Accessed December 10, 2014. http://world.honda.com/
motorcycle-picturebook/Airbag/.
9) Honda Motor Co., Ltd. 2008. “Honda Begins Testing of Advanced Safety Vehicles and Driving Safety Support Systems on
Public Roadways: Honda Cooperating on Development of Driving Safety Support Systems Using Inter-Vehicle and Road-toVehicle Communications to Help Reduce Traffic Accidents.” Honda Worldwide, March 24. Accessed December 10, 2014.
http://world.honda.com/news/2008/4080324Advanced-Safety-Vehicles/.
10) Bridgestone Corporation. 2014. “Key components of Run-Flat Technology tires.” RFT: BRIDGSTONE Run-Flat Technology.
Accessed December 10, 2014. http://www.bridgestone.com/sc/runflat-system/technology/index.html.
11) Honda Motor Co., Ltd. 2013. “Honda Unveils MC-β, New Micro-sized EV: Field tests will begin in Kumamoto, Saitama andMiyakojima.” Honda Worldwide, November 19. Accessed December 10, 2014. http://world.honda.com/news/2013/
4131119MC-Micro-sized-EV/index.html.
12) Ministry of Land, Infrastructure, Transport and Tourism. 2013. “Cho kogata mobiritei no donyu sokushin” [Promotion ofultra-compact mobility vehicles]. Accessed December 10, 2014. http://www.mlit.go.jp/common/000986236.pdf. (inJapanese)
Recommended Reading
1) Society of Automotive Engineers of Japan, Inc., ed. 2009. Jidosha no hyakka jiten [Encyclopedia of automobiles]. Maruzen
Co., Ltd. (in Japanese)2) Ministry of Land, Infrastructure, Transport and Tourism. 2008. “Senshin anzen jidosha ni kansuru kenkyu seika hokokusho:
ASV (Advanced Safety Vehicle) no kenkyu seika to kongo no gijutsu houshin” [Report on research results regarding
Advanced Safety Vehicle: Results of research on ASV and future technological guidelines]. Accessed December 10, 2014.
http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/asv1report.pdf. (in Japanese)3) Ministry of Land, Infrastructure, Transport and Tourism. 2001. “Senshin anzen jidosha (ASV) suishin keikaku (dai 2 ki) ni
kansuru hokokusho” [Report on promotion plan for advanced safety vehicles (2nd stage)]. Accessed December 10, 2014.
http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/asv2report.pdf. (in Japanese)4) Ministry of Land, Infrastructure, Transport and Tourism. 2006. “Senshin anzen jidosha (ASV) suishin keikaku hokokusho:
dai 3 ki ASV keikaku ni okeru katsudo seika ni tsuite” [Report on the promotion plan for advanced safety vehicles: results of
ASV promotion plan (3rd stage)]. Accessed December 10, 2014. http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/
asv3seikahoukokusyocorrection.pdf. (in Japanese)5) Ministry of Land, Infrastructure, Transport and Tourism. 2011. “Senshin anzen jidosha (ASV) suishin keikaku hokokusho:
dai 4 ki ASV keikaku ni okeru katsudo seika ni tsuite” [Report on the promotion plan for advanced safety vehicles: results of
ASV promotion plan (4th stage)]. Accessed December 10, 2014. http://www.mlit.go.jp/jidosha/anzen/01asv/resourse/data/
asv4pamphlet_seika.pdf. (in Japanese)
Practical application projects for reference
A study on the role and limitations of motorcycles as a means of urban transport in Southeast Asia: 156–159

Chapter8

Traffic
psychology
8.1

Perception and cognition of drivers

When operating a vehicle, drivers gather information from the surroundings based on their intended
purpose and process the information accordingly to operate the steering, pedals, and switches. Although
this appears to be a series of simple tasks, these actions involve various mental processes such as predicting changes in the surrounding environments, gathering information for subsequent actions, and detecting and handling dangerous situations. The process of gathering external information is defined as perception, and the process of understanding and handling the external information is defined as cognition.
The perception and cognition of massive amounts of information is performed largely automatically andunconsciously, in accordance with complex rules and under strict time limits. These mental processes,
which are performed without any errors, are critical for safe driving.
As in Figure 1, all humanAttentional resource (divided attention)
behaviors, not limited to driving,are represented in a schematic
diagram. 1) According to this [Knowledge-based]
Interpretation ofDecision making
Planning
model, human behaviors involve
situations
and task selection
three levels of information processing (skill-, rule-, and knowledge-based) between the input
of information and the output ofaction. The perceptual featuresof sensory information obtained
via the sensory organs are analyzed to recognize the content of
the information. If the content isalready well-known, appropriate[Rule-based]
Featurerecognition

Correlation between
situations and tasks

Application of
stored rules

Inhibition

Automatedsensorimotor
patterns[Skill-based]
Feature extraction
Selective attention
Sensory input

Actionresponses are elicited quickly at Figure 1. Three-level behavior control model based on Rasmussen’s SRK modelChapter 8: Traffic psychology｜81

the point of feature formation. This skill-based response is rapid and unconscious but is also fixed andinflexible. When it is necessary to behave in accord with informational content, rules for selecting a
response are recalled in order to behave appropriately. Attention is not required when the behavior to be
performed is simple and familiar, whereas a certain degree of attention is required when the behavior isunfamiliar. When the information is novel and totally unfamiliar, information processing is “knowledge-based,” which is a conscious process to interpret information and make behavioral decisions. A
behavior at this level can be slowly but flexibly controlled, and requires sufficient attention.
Most basic driving operations, such as steering and pedal operation, are controlled at the skillbased level, while rule-based processing is required when drivers have to think about driving. For example, drivers have to behave at the knowledge-based level when they encounter an irregular road situationin which the road priority is unclear and when they have to make a route to the destination. In models
of driver behavior, hierarchical concepts (operational, tactical, and strategic) have been used to explain
driver behavior.2) In particular, the operational and tactical levels apparently correspond to the skill- andrule-based levels, respectively.
In addition, attention plays an important role in driving. Attention may be classified into selective
attention for selectively gathering information and divided attention for working as mental energy to
execute actions. The cognitive process in which these two processes are deeply involved is also shown in
Figure 1.

8.2

Hazard perception

A hazard is a source of danger that may cause an accident, and hazard perception is defined as the detection of hazards and the recognition of their characteristics while operating a vehicle. Hazards are divided
into overt hazards (e.g., visible pedestrians ahead) and latent hazards (e.g., unseen pedestrians in blind
spots), and hazards need to be detected in a timely manner. Hazard perception may also be regarded asa situational awareness step required for securing safety.3)
When operating a vehicle, hazard perception relies for the most part on vision. To capture hazards
by central vision, which is highly effective but limited to a narrow area, visual information must be
obtained by looking at places where the presence of hazards is highly probable, while anticipating andpaying careful attention to the appearance of hazards. Selection of visual information is strongly affectedby drivers’ expectations and value judgments. If a driver has insufficient intention to detect hazards,“inattentional blindness” can occur, which is a phenomenon where visible objects are viewed but
overlooked.4)
Drivers are also required to quickly determine which elements or situations are hazardous based on
their experiences and knowledge. To do so, drivers must be able to store hazardous experiences, scan thecontents quickly, and recall the experiences. Drivers gradually acquire hazard-related knowledge
through driving experiences and develop a schema about hazards. Schemas are generated based on thepast experiences of events, actions, and objects, and are constructed with a number of generalized

82｜Theory

concepts.5) Behavior control by schemas is generally an unconscious and automatic process,6) and schemas compensate for insufficient information by using default values.5) Schemas are the basis for smooth
human behavior. By constructing schemas, drivers can recognize scenes containing hazards more correctly and comprehensively, as shown by previous studies.7), 8)
For preventing accident, it is extremely important to perform hazard perception effectively. Consequently, various hazard perception tests have been developed and incorporated into driver’s license
examinations in Western countries as well as in Japan.9) In a typical hazard perception test, drivers
observe a video of the view from the driver’s seat and push a button as soon as they discover a hazard.
Drivers’ hazard perception ability is evaluated based on the time taken to detect and react to a hazard
and the overall detection rate. In general, skilled drivers have short detection and reaction times and ahigh detection rate compared with novice drivers.10), 11) Previous studies of eye movements during hazard perception testing suggest that the difference in reaction time between skilled and novice drivers isdue to the difference in time taken to process and determine the degree of hazard rather than the difference in their respective abilities to detect hazards.12), 13)
In addition, due to the increasing number of elderly drivers, research is currently underway toinvestigate age-related changes in hazard perception ability. While some studies have shown that hazard
perception test scores are low among elderly drivers compared with younger drivers,14), 15) other studies
have revealed no age-related difference in hazard perception abilities.16) Further studies are needed toclarify whether hazard perception test scores among elderly drivers are affected by a decline in visualfunction itself (e.g., a decline in contrast sensitivity); a reduction in the useful field of view, which isindicative of an overall decline in the mechanism of attention; or age-related modifications in the structure and mechanism of the schema that is the basis of hazard perception.
Educational and training programs are offered to improve hazard perception ability. One of themethods is to point out hazards hidden in still images and videos of traffic scenes. As mentioned earlier,hazard perception is based on a schema constructed with a variety of knowledge regarding dangers. To
perform hazard perception effectively, drivers should not only memorize extensive knowledge about
typical and individual hazards and immediately retrieve knowledge appropriate for a particular scene,
but also generalize such knowledge to meet novel situations. Therefore, it is necessary to educate drivers
and give them an understanding of the processes by which hazards cause accidents and the informationthat makes hazard detection easier, rather than simply teaching them how to respond to individual hazards. For example, driving schools in Japan already provide hazard perception training in the form of
discussion-based training on hazard prediction and driving while predicting hazards. To improve hazard perception education, the incorporation of psychological approaches based on the perceptual andcognitive processes of hazard prediction into the content of driver’s education should be considered.

8.3

Risk taking

In traffic psychology, the term “risk taking” has long been used as a concept associated with accidents

Chapter 8: Traffic psychology｜83

based on the assumption that accidents are more likely caused by drivers with a tendency to act despite
being aware of potential risks. In particular, risk taking is given as the reason for high accident rates
among young drivers.
When individuals exhibit a tendency toward taking risks, they may behave in the same way but fordifferent reasons; some enter risky situations without knowing what is dangerous, while others take risks
despite being aware of the danger, for example to seek thrills. When drivers enter intersections against a
red traffic signal, they may do so with or without being aware of the signal. From the perspective of individual traits, the former may have problems with hazard perception, while the latter may have behavioral problems, such as a risk-taking tendency.
Trimpop defines risk taking as all actions that are engaged at the time of perceiving elements ofuncertainty or possibility of loss.17) Accordingly, almost all traffic behaviors involve risk taking due to theuncertainties associated with such behaviors compared with other ones in daily life.
Traffic behaviors reflect mental processes performed under extremely high time pressure, and theirfeatures affect risk-taking behaviors. Driving and traffic behaviors are characterized by the rapidity andcontinuity of the process between hazard or risk perception and risk taking via decision making.
As covered in the previous section, good hazard perception ability, for foreseeing and detecting in
advance the objects or situations that may lead to accidents, is essential for safe driving. However, therisk of potential accidents linked to one’s own driving is evaluated with respect to those hazards in acomprehensive manner. If one’s driving skills are judged to be sufficient to handle driving challenges,
then risks are evaluated as being low even though hazards are perceived correctly.
However, even when risks are evaluated to be high, if utility such as shortened time or increased
admiration from others is judged more important, it is likely that the risks will be accepted and risk-taking behaviors will emerge. If gains are made by engaging in high-risk behaviors, the risks are rewarded,
generating positive reinforcement. For example, if the time required to reach the destination is shortened by traveling at high speed, then the behavior is rewarded. In other words, driving behaviors areassociated with gains due to stress release and rushed driving. This quality, where gains exert an effecton risk taking or risk avoidance behaviors, is called risk utility.
Human motivation involves various types of risk utility, such as releasing stress, violence, expressing independence, increasing arousal levels, increasing on-road travel efficiency (in a hurry to reach
one’s destination), rebelling against adult authorities, and receiving admiration from peers. Furthermore,compared with middle-aged individuals, young individuals tend to attach importance to appearance andstyle, but not safety features, when purchasing a car. These motivations often affect risk-avoidance
behavior.
Particularly in recent years, sensation seeking has been attracting a lot of attention. According toZuckerman, sensation seeking is defined as an individual trait that plays a role in seeking various, novel,
complex, and intense sensations or experiences and for taking physical, social, legal, and financial risks
to gain such experiences.18) According to this definition, sensation seeking is nothing but a motivation
for taking risks.
As the knowledge of risk utility increases, it has become apparent that the improvement of risk

84｜Theory

perception alone is not enough to reduce the risk-taking tendency or increase the risk-avoidance tendency of drivers. To understand why drivers behave in certain ways, it is important not only to study thepossibility of accidents as risk non-utility, but also to simultaneously take into account risk utilities,
including sensation seeking and admiration of others.
Most active discussions regarding risk acceptance and avoidance in recent years are about the issues
surrounding the theories of risk compensation and risk homeostasis. Risk compensation is a tendencyof traffic participants to offset or reduce the merits of safety measures by engaging in risky behavior. For
example, even when the safety of streets is improved, traffic participants may partly negate these safety
benefits by behaving negatively, such as increasing the speed of the vehicle and failing to perform safety
checks.
According to the theory of risk homeostasis proposed by Wilde,19) we as individuals set target risk
levels for various activities and modify our behaviors to achieve or maintain these levels. As a result, thenumber of accidents will not be reduced unless safety measures are designed to decrease target risk levels, suggesting that behavior moves towards danger to the same extent as does the merit generated by
the safety measure. However, risk homeostasis theory is often criticized because it is unlikely that individual drivers can estimate safety merits accurately.

8.4

Behavior and education of elderly drivers

As it is a challenge associated with an aging society, the prevention of accidents among elderly drivers is
discussed actively. However, careful discussions are needed to clarify whether elderly drivers are indeed
high risk compared with younger drivers, because even with some form of functional decline, elderly
drivers are able to reduce the actual risk of accidents by avoiding high-risk driving (driving at night or
in rain) or driving carefully, for example, by slowing down. Such “compensatory driving” behaviors
among many elderly drivers have already been demonstrated by many studies.
However, research has also revealed that the accident rate for a given driving distance is higher
among elderly drivers compared with other age groups, except for young adults. According to Fujita, thenumber of fatal accidents and traffic accidents among elderly drivers is respectively 3 and 1.5 times thatof other age groups excepting young adults.20)
Poor driving performance is thought to be the reason for high accident rates among elderly drivers.
Using behavioral indicators (safety checking behavior and speeding behavior) and driving assessment
indicators used by instructors to evaluate the driving performance of elderly drivers, Renge et al.
revealed that the number of times elderly drivers looked to the right and left for oncoming traffic was
fewer than that of drivers in other age groups14) (Fig. 2). Although no age-related difference was observedin the speed during routine driving, at the intersections with a stop sign, elderly drivers drove faster atintersections with poor visibility or stop signs, compared with other age groups, indicating that manyelderly drivers fail to perform one of the safe driving basics: stopping to check traffic.
However, as mentioned earlier, many studies have reported that elderly drivers counterbalanceChapter 8: Traffic psychology｜85

functional decline and the deteriorationof their driving performance with com-

Safety check scores70

pensatory driving behavior. Matsuura,
Ishida, and Mori developed the safe driv-

60

ing workbook, which includes dangerous
driving scales and compensatory driving
scales to test their hypothesis that elderly
drivers engage in compensatory driving
behaviors to avoid dangerous situations

50
40
60.1

30

upon realizing potentially dangerous

56.8

50.0

45.1

Middle-aged Pre-elderly
Elderly
Elderly
individuals individuals individuals individuals
aged
aged
65–74 years ≥75 years

Figure 2. Safety check scores by age groupdriving performance due to functional
decline.21) Their study revealed that dangerous driving and compensatory driving scores increased withage. Furthermore, as the scores for dangerous driving increased, elderly drivers were involved in more
accidents and committed more violations, and their driving behaviors were rated lower by instructors.
A previous study performed at a driving school has shown the effectiveness of a program that educates elderly drivers how to comply with stop signs and verify traffic safety.22) The educational program
was developed because elderly drivers are generally not good at stopping at stop signs or checking traffic
safety. In this program, using the behavior check and feedback approach, (1) elderly drivers drove
through the predetermined course at the school using one of the school cars, and their performance wasvideotaped (performance-based diagnosis), and (2) elderly drivers evaluated their driving behavior on
the video and received feedback from the instructors.
After converting this educational method
Indicator value
into a practical coaching method, developing160
an educational manual for instructors, and140
training them, Renge et al. asked appropriatequestions and provided feedback to cause pro120
gram participants to recognize their own prob100
lems. 23) In the program, participants slowed
100
down at intersections and increased their number of traffic safety checking steps comparedwith non-participants (Fig. 3). The efficacy
weakened but persisted over one month after
the program.
Although it is sometimes questioned

100

Individuals in the program

Individuals not in the program

134.9
109.2

115.2
98.7

80
Driving 1
Driving 2
Driving 3(before the(immediately(one month later)
educational program)
after theeducational program)

Figure 3. Educational efficacy in terms of total number ofsafety checks

whether educational programs for elderly individuals are effective, a certain level of efficacy can be expected with the use of this method, where program participants check their own driving performance and receive appropriate feedback.

86｜Theory

8.5

Behavior and education of bicycle users

The rate of bicycle-related accidents is high among children and elderly individuals, and failing to stopat stop signs, ignoring traffic signals, traveling the wrong way, and crossing streets inappropriately havebeen indicated as potential reasons. Furthermore, analysis performed by the International Associationof Traffic and Safety Sciences (IATSS) in 1995 and adjusted for the number of licensed drivers and fortraveling time has shown that elderly individuals with no driver’s license have a high rate of accident. 24)
Although a similar trend is observed among young and middle-aged individuals, the problem is more
serious for elderly individuals because of the low proportion of licensed drivers in this group.
In 2012, the IATSS also conducted a study using the driving lanes at a driving school to investigate
behavioral characteristics such as stopping and checking the safety at intersections. 25) The study evaluated where bicycles traveled in their lane and safety checking behavior (how many times bicycle users
looked to the right and left at intersections, and how thoroughly they did so).
Figure 4 shows the effect of obtaining a
Individuals with a driver’s license
100

Individuals without a driver’s license

80

Scores

60

69.0
53.0
40.5

40
22.7
20
0
Bicycling

Walking

Figure 4. Effect of obtaining a driver’s license on total
safety check scores for bicycling and walking

driver’s license, which includes the benefits ofdriving experience and drivers’ education. The
results indicate that higher safety check scoresat intersections were obtained by bicycle users
with a driver’s license than by those without.
The former also scored higher for location of
their bicycle on the road, showing that theychoose to travel closer to the roadside than thelatter did.

However, bicycle users without a driver’s
license set low standards for safety checking,the location of their bicycle, and driving behavior, thereby showing high-risk behavior, when riding abicycle compared with when walking. We interpreted this to mean that elderly bicycle users who have adriver’s license can readily engage in appropriate risk avoidance behavior, owing to driving skills andknowledge previously acquired at driving school or through their own driving experiences. The early
establishment of educational programs for bicycle users that are equivalent to driver’s education programs may reduce accidents among bicycle users who do not have a driver’s license, and therefore, proactive educational programs should be provided in cooperation with schools and local traffic safety
associations.
Using an observational and coaching method, Ogawa developed a bicycle education program forhigh school students based on his hypothesis that a lack of awareness of one’s behavior and role as acyclist is a factor causing unsafe behaviors.26) By applying the basic principles of coaching, observationof others was performed in several steps such as group discussions, video viewing, and bicycling simulation. Before and after the educational program, high school students created 20 self-awareness sentences
starting with “I” using the 20-responses technique. Comparison of the sentences revealed that althoughChapter 8: Traffic psychology｜87

the students provided general bicycling-related descriptions before the program, they increased both thenumber of statements and the descriptions about proactively securing safety, especially the safety-checking category, after the program. Such bicycling education programs that enhance self-awareness should
be promoted because they are suited for and benefit adolescent individuals who are transitioning into
adulthood, and provide lifelong benefits.

References
1) Shinohara, Kazumitsu. 2011. “Chui to hyuman era: Kotsu anzen to chui mondai o chushin toshite” [Attention and humanerror: On traffic safety and attention problem]. In Theories and Applications of Cognitive Psychology 4: Attention and Safety,edited by Etsuko Harada, and Kazumitsu Shinohara, 186–208. Kitaohji Publishing. (in Japanese)2) Shinar, D. 2007. Traffic safety and human behavior. Elsevier.
3) Horswill, M. S., and F. P. McKenna. 2004. “A cognitive approach to situation awareness.” In A cognitive approach to situation
awareness: theory and application, edited by Banbury, S., and S. Tremblay. Ashgate publishing.
4) Chabris, C., and D. Simons. 2010. The invisible gorilla: and other ways our intuitions deceive us. HarperCollins Publishers.
5) Shinohara, Kazumitsu. 2013. “Ninchi to hyuman era” [Cognition and human error]. In Human Factors Psychology for a New
Era of Safety and Comfort, edited by Kazumitsu Shinohara, and Takahiro Nakamura, 41–59.Yuhikaku Publishing. (inJapanese)6) Harada, Etsuko, and Takatsune Kumada, Kazumitsu Shinohara, eds. 2013. “Chui to suikou kinou” [Attention and executivefunction]. In The handbook of cognitive psychology, edited by The Japanese Society of Cognitive Psychology, 94–95. Yuhikaku
Publishing. (in Japanese)
7) Benda, H. V., and C. G. Hoyos. 1983. “Estimating hazards in traffic situations.” Accident Analysis and Prevention Vol. 15: 1–9.
8) Borowsky, A., T. Oron-Gilad, and Y. Parmet. 2009. “Age and skill differences in classifying hazardous traffic scenes.” Transportation Research Part F: Traffic Psychology and Behaviour Vol. 12: 277–287.
9) Nagayama, Yasuhisa. 2009. Kanrisha no tameno kiken yosoku unten kyoiku: nichi, bei, o no kikenyosoku kyoiku to kyozai,
tesuto mondai [Driver’s risk prediction education for instructors: The comparison of materials and tests for the risk prediction education among Japan, the United States, and Europe]. Kigyo Kaihatsu Center. (in Japanese)
10) Scialfa, C. T., M. C. Deschênes, J. Ference, J. Boone, M. S. Horswill, and M. Wetton. 2011. “A hazard perception test for novice drivers.” Accident Analysis and Prevention Vol. 43: 204–208.
11) Borowsky, A., D. Shinar, and T. Oron-Gilad. 2010. “Age, skill, and hazard perception in driving.” Accident Analysis and Prevention Vol. 42: 1240–1249.
12) Huestegge, L., E. M. Skottke, S. Anders, J. Müsseler, and G. Debus. 2010. “The development of hazard perception: Dissociation of visual orientation and hazard processing.” Transportation Research Part F: Traffic Psychology and Behaviour Vol. 13:
1–8.
13) Wetton, M. A., M. S. Horswill, C. Hatherly, J. M. Wood, N. A. Pachana, and K. J. Anstey. 2010. “The development and validation of two complementary measures of drivers’ hazard perception ability.” Accident Analysis and Prevention Vol. 42:
1232–1239.
14) Renge, Kazumi, Tomikazu Ishibashi, Masaaki Oiri, Hiro Ota, Shigeyuki Tsunenari, and Marehiro Mukai. 2003. “Korei
doraiba no unten pafomansu to hazado chikaku” [Driving performance and hazard perception of elderly drivers]. Japanese
Journal of Applied Psychology Vol. 29, No. 1: 1–16. (in Japanese)15) Renge, Kazumi, Masahiro Tada, and Marehiro Mukai. 2014. “Korei doraiba to chunen doraiba no risuku tekingu kodo ni
kansuru jisshoteki kenkyu” [Empirical study on the risk taking behavior by elderly and middle-aged drivers]. Japanese Journal of Applied Psychology Vol. 39, No. 3: 182–196. (in Japanese)
16) Underwood, G., N. Phelps, C. Wright, E. van Loon, and A. Galpin. 2005. “Eye fixation scanpaths of younger and older drivers in a hazard perception task.” Ophthalmic & Physiological Optics: The Journal of the British College of Ophthalmic Opticians(Optometrists) Vol. 25: 346–356.
17) Trimpop, R. M. 1994. The psychology of risk taking behavior. North-Holland.
18) Zuckerman, M. 1994. Behavioral expressions and biosocial bases sensation seeking. Cambridge University Press.
19) Wilde, G. J. S. 2001. Target risk 2: a new psychology of safety and health. PDE Publications.

88｜Theory20) Fujita, Goro. 1996. “Kotsujiko ritsu, kikenbakuro do oyobi untenkodo no nenrei ni yoru chigai” [Difference in the ratio oftraffic accidents, the degree of danger exposure, and driving behaviors based on age]. Reports of the Scientific Police ResearchInstitute. Research on traffic safety and regulation Vol. 37, No. 2: 48–57. (in Japanese)21) Matsuura, Tsuneo, Toshiro Ishida, and Nobuaki Mori. 2008. Korei doraiba no tameno anzen unten wakubukku [The Safe
Driving Workbook for elderly drivers]. Kigyo Kaihatsu Center. (in Japanese)
22) International Association of Traffic and Safety Sciences. 2004. Korei doraiba eno kyoiku puroguramu to shien shisutemu no
kaihatsu: heisei 15 nendo kenkyu chosa hokokusho [Development of educational programs and a support system for elderly
drivers: research report 2003]. International Association of Traffic and Safety Sciences. (in Japanese)23) Renge, Kazumi, Hiro Ota, Marehiro Mukai, and Kazuhisa Ogawa. 2010. “Kochingu ho o mochiita korei doraiba eno kyoiku
puroguramu no koka” [The effectiveness of educational programs for elderly drivers using a coaching method]. Japanese
Journal of Traffic Psychology Vol. 26, No. 1: 1–13. (in Japanese)24) International Association of Traffic and Safety Sciences. 1995. Korei hokosha, jitensha joyosha no anzen ni taisuru untenkeiken no koka ni kansuru chosa kenkyu: heisei 6 nen kenkyu chosa hokokusho [Research study on the effectiveness of driving
experience of elderly pedestrians, cyclists, and drivers against safety: research report 1994]. (in Japanese)25) International Association of Traffic and Safety Sciences. 2012. Kodomo kara koreisha madeno jitensha riyosha no shinri kodo
tokusei o fumaeta anzen taisaku no kenkyu (III): kenkyu chosa purojekuto hokokusho [Study of safety measures based on thepsychological and behavioral characteristics of cyclists from children to the elderly: a report of research project]. (inJapanese)
26) Ogawa, Kazuhisa. 2014. “Method Development for Safety Education Based on Students’ Self-Understanding.” Memoirs of the
Tohoku Institute of Technology: Ser. II: Humanities and Social Sciences Vol. 34: 1–9. (in Japanese)
Recommended Reading
1) Wickens, C. D., and J. S. McCarley. 2008. Applied attention theory. CRC Press.
2) McKenna, F. P., and M.S. Horswill. 1999. “Hazard perception and its relevance for driver licensing.” IATSS Research Vol. 23:
36–41.
3) Endsley, M.R. 2000. “Theoretical underpinnings of situation awareness: a critical review.” In Situation awareness analysis andmeasurement, edited by M. R. Endsley, and D. J. Garland, 3–28. Lawrence Erlbaum Associates.
4) Marottoli, R.A., and E. D. Richardson. 1998. “Confidence in, and self-rating of, driving ability among older drivers.” Accident
Analysis and Perception Vol. 30: 331–336.
5) Marottoli, R. A., E. D. Richardson, M. H. Stowe, E. G. Miller, L. M. Brass, L. M. Cooney Jr., and M. E. Tinetti. 1998. “Development of a test battery to identify older drivers at risk for self-reported adverse driving events.” Journal of American Geriatrics Society Vol. 46, No. 5: 562–568.
6) Matsuura, T. 2011. “Older drivers’ risky and compensatory driving: Development of a safe driving workbook for older drivers.” In Traffic Psychology: An International Perspective, edited by D. Hennessy, 87–113. Nova Science Publishers.
7) Oxley, J., B. Fildes, B. Corben, and J. Langford. 2006. “Intersection design for older drivers.” Transportation Research Part F:
Traffic Psychology and Behaviour Vol. 9: 335–346.
8) Renge, K. 1998. “Drivers’ hazard and risk perception, confidence in safe driving, and choice of speed.” IATSS Research Vol.
22, No. 103-110.
Practical application projects for reference
Identification of brain regions associated with the central and peripheral visual field and applications for improving traffic safety:
164–167
An educational program for better control of emotions while driving: 168–171
A study on safety measures considering the psychological behavior characteristics of cyclists, from adolescents to the elderly:
172–175

Chapter9

Traffic safety andmedicine
9.1

Traffic accident casualty statistics

Traffic accident casualty statistics issued by the Japanese National Police Agency (NPA) are for on-road
accidents as defined by the Road Traffic Act that resulted in fatality within 24 h of the accident. This statistic is the conventional reference when discussing traffic accident fatalities. Beginning in 1993, to better grasp the number of deaths occurring after that 24-h window and to allow for easier international
comparisons, separate statistics that additionally include deaths occurring between 24 h and 30 days following an accident have also been calculated. NPA statistics for injury from traffic accidents classify
injuries requiring treatment for less than 30 days as minor injuries, and those requiring 30 days or moreof treatment as serious injuries. General injury statistics report a combination of both minor and serious
injuries. In contrast, demographic statistics tally all persons dying within 1 year of a traffic accident,
regardless of the site of the accident. Note that regardless of the period following the accident, medicallyspeaking, all deaths due to involvement in modes of transportation are considered traffic accident
deaths.
Nationwide statistics for 24-h traffic fatalities since 1989 peaked at 11,452 in 1992, and then fell for
13 consecutive years to 9,943 fatalities in 1996, 7,768 in 2003, 4,968 in 2009, and 4,373 in 2013. Fatalities
between 24 h and 30 days folPersons
lowing a traffic accident were
1,176 in 2003, 863 in 2009, and
779 in 2013, this being a similar
reduction to the 24-h traffic
fatalities, being equal to 10–20%
the number of fatalities within
24 h of accidents for that same
year (Fig. 1). The number of traffic accident-related injuries also
fell over 9 consecutive years to

9,000
8,000
7,000
6,000
5,000

Death within 30 days

4,000

Death within 24 h

3,000
2,000
1,000
0

2004

2005

2006

2007

2008

2009

2010

2011

2012

Figure 1. Traffic fatalities

2013

Year

90｜Theory

781,494 in 2013, withapproximately 6% of
injuries being serious
injuries and requiring over 30 days oftreatment (Fig. 2).
This reduction
in casualties is theresult of severale f for t s , i n clu d i ng
legal efforts such as
strengthening laws
against drunk driv-

Persons
1,200,000
1,000,000
800,000
600,000

Injured

400,000

Seriously injured

200,000
0

2004

2005

2006

2007

2008

2009

2010

2011

2012

2013

Year

Figure 2. Injuries due to traffic accidents
Persons
3,500

ing and making seat3,000
belt usage manda2,500
tory, the development
15 or less2,000
of accident-resistant
16–29
road environments,
30–49
1,500
50–64
automobile struc1,000
65 and abovetural developments,
500
improvements in0public transportation
2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Year
Figure 3. Traffic fatalities by age (death within 24 h)facilities and medical
rescue systems, andcomprehensive accident prevention measures such as traffic safety education. Viewing casualty statistics
by age, the ratio of fatalities and injuries among the elderly is relatively high, and the amount of reduction experienced among all age groups was smallest among the elderly; the rate of elderly fatalities isapproximately 6.6 times that of other age groups, and the rate of serious injury is approximately 3 times
as high (Fig. 3).1)
While the number of traffic accident-related fatalities has reduced for all age groups, the ratio ofelderly fatalities overall is increasing since the reduction rate for elderly fatalities is small. To address thisissue, since June 2009 persons aged 75 years or older wishing to renew their driver’s license must
undergo a cognitive function test, and must furthermore undergo a driving course designed for theelderly. Other traffic accident-prevention measures targeting elderly pedestrians will likely be particularly needed.2)

Chapter 9: Traffic safety and medicine｜91

9.2

Damage due to traffic accidents

One feature of personal injury due toautomobiles is that even when injury
externally seems to be minor, internal
damage can be quite severe. Automobile
accident-related fatalities are categorized
into deaths of pedestrians, drivers, andpassengers, and other possible categorizations are for fatalities by motorcyclists
and bicyclists. Each group has characteristic injuries (Table 1).
Injuries to pedestrians are categorized as those occurring due to the initial

Table 1. Traffic accident damage by riding position in terms of
mechanism of injury
1. Pedestrians
Injury due to bumper, hood, windshield
Injury due to being run over (tire marks, abrasion) or dragged
Primary injuries: Injury due to initial impact
Secondary injuries: Injury due to being flung up and colliding
with the vehicle
Tertiary injuries: Injury due to impact with the ground
2. Drivers
Injury due to steering wheels, seatbelts, and air bags
Injury due to dashboards, windshields
Cervical spine injury (whiplash)Lower extremity injury or pelvic fracture due to legs being
extended to depress brake at impact
Injury due to being ejected from vehicle

impact (primary injuries), those due tobeing flung up and subsequently colliding
3. Passengers
Injury due to steering wheels, seatbelts, and air bagswith the vehicle (secondary injuries), andInjury due to dashboards, windshields
those due to impact with the ground (terCervical spine injury (whiplash)
Injury due to being ejected from vehicle
tiary injuries). Pedestrian injuries arehighly dependent on the automobile’s
form and its speed at the time of impact.
For standard passenger vehicles, pedestrian impact with the front bumper will result in lower extremity
injuries at approximately bumper height, but in the case of hoodless cab-type vehicles, primary injuries
will occur in the chest and lumbar regions. Such correspondence between primary injury locations andvehicle collision sites are vital to vehicle identification in hit-and-run accidents. In the case of low-speed(around 20 km/h) accidents, pedestrians are thrown in front of or to the side of vehicles. In the case of
mid-speed (20–60 km/h) accidents, pedestrians tend to be flung up onto the hood or windshield. In
high-speed (60–100 km/h) accidents, pedestrians are flung over the vehicle, and subsequently impact
with the ground. In low-speed accidents where pedestrians are thrown in front of the vehicle, in somecases the pedestrian will be run over by the same vehicle, and when hit by cars at high speed, pedestrians will often sustain severe head injuries due to the subsequent impact with the ground.3) Brain damage
is a very severe injury frequently seen in traffic accidents, and diagnosis and pathology of brain damage
are important issues related to saving the lives of accident victims (Fig. 4).4)
Damage to drivers and passengers occurs when the vehicle collides with other vehicles or roadsidestructures, and resulting in contusions from being hit by objects from within the vehicle. The same canoccur when vehicles roll over or when passengers are ejected from the vehicle. When the steering wheel
impacts the driver’s chest or abdomen, cardiac rupture and other serious injuries can occur. Seatbelts
prevent the head and chest from impacting the windshield and steering wheel, and furthermore prevent
ejection from the vehicle, which can result in serious injury. The usage or non-usage of seatbelts is an

92｜Theory

Extremities Other
2% 1%
Lumbar6%
Abdomen
7%
Chest
22%

Whole
body
6%

important predictor of injury severity. Seatbelt usage isrequired even when airbags are present; rapidly inflating airbags can cause serious contusions to the chest and abdomen if
seatbelts are not worn.
Extent of damage is quantified to objectively study traffic accident damage. In 1971 the U.S. Association for the

Head or face
51%

Advancement of Automotive Medicine created the Abbreviated Injury Scale (AIS) and performed research such as comparisons of treatment prognosis between multiple facilities,
the relationship between collision speed and damage, and dif-Neck
5%
Figure 4. Fatalities by injury site
(2013; death within 30 days; 5,152 persons)

ferences in damage when seatbelts were or were not worn. The
AIS divides the body into seven areas (body surface, head,neck, chest, abdomen and pelvic organs, spine, and extremi-ties), and assigns scores to each area based on damage according to 6 severity levels (1: minor; 2: moderate; 3: serious; 4:
severe; 5: critical; 6: fatal). The largest score is also called maximum AIS. There is also the injury severity
score (ISS), a severity evaluation method for multiple trauma that is calculated based on the AIS. In theISS, the body is divided into six areas (head and neck, face, chest, abdomen, extremities and pelvic
organs, and body surface), and assigns an AIS score of 1–5 to each injury. The ISS score is calculated bytaking the maximal score from each area, and summing the squares of the top three AIS scores. Accordingly, the maximum value is 75. Alternatively, if any single location has an AIS score of 6, the ISS score is
automatically calculated as 75. The ISS score represents severity well and is correlated with death rates,
particularly in the case of multiple trauma patients. Analysis of mechanism of injury through analysis ofthree factors in traffic accidents—personal injury, accident vehicle, and scene of the accident—provides
fundamental data for ensuring the safety of persons, vehicles, and road environments to prevent theoccurrence of accidents (active safety) and reduces damage to passengers and pedestrians following
accidents (passive safety).

9.3

Emergency medical care

9.3.1 Regional characteristics and the importance of immediacy in emergency medicine
Emergency medical care is the keystone of medicine, and is considered by all citizens to be the last bastion in the medicine for care of unexpected acute pathology.
Acute pathology is characterized by progress, regardless of differences in the degree of onset. A
sudden headache may indicate subarachnoid hemorrhage. Chest pain may indicate acute myocardial
infarction. A fall from a high location will likely lead to severe injuries caused by high-energy trauma.
All of these cases require rapid transport to a hospital. Brain aneurysm rupture, which is known to be acause of subarachnoid hemorrhage, has a high probability of fatality due to a second rupture on theChapter 9: Traffic safety and medicine｜93

same day of onset. Acute myocardial infarction can easily lead to a form of arrhythmia called ventricularfibrillation within 4 h of onset. High-energy trauma is highly likely to result in severe injury, and failure
to determine a course of treatment by performing a diagnosis of the injury within 1 h of occurrence has
a statistically significant increase in likelihood of death.5)
Maintaining an emergency care supply system that provides an “anytime, anywhere, anyone” levelof care for such acute pathology is extremely important but at the same time very difficult. In Japan, differences in treatment outcomes for severe trauma have been reported by region and facility. To address
this, Japan Trauma Care and Research developed a course called Japan Advanced Trauma Evaluation
and Care (JATECTM) to demonstrate a protocol for trauma care, and is working toward its implementation through off-the-job participation throughout the country. The JATEC course was originally centered on doctors, but given the importance of team medical care, it was later extended to include nurses.
Year after year, the course has been confirmed to contribute to substantial improvement of death rates
due to trauma.6)
The status of emergency medical care takes on a different meaning between large and small cities.
In many hospitals in large cities there are many specialists capable of providing leading-edge treatment,
but for example in Tokyo, there have been unfortunate incidents of death believed to have been due torefusal of hospitals to admit patients or delays in transporting patients between hospitals. In contrast,
hospitals in smaller cities often concentrate the role of emergency care for an entire region in one location, requiring them to admit patients with both minor and severe injuries, which presents the danger oflosing the ability to function as a hospital. Setting aside the issue of which problem is easier to solve,
given this situation it is necessary to consider the significance of the existence of emergency care within
the framework of the community. Such problems must thus be solved through the combined efforts of
the local hospitals, emergency services, fire brigades, police departments, and governments of each individual region.7)
9.3.2 Current status and problems related to time for emergency medical careTime is of the essence for reducing death and sequela in emergency care, so it is necessary that ambulances reach emergency patients as quickly as possible, that hospital selection is rapidly performed, andthat the time to arrival at the hospital is as short as possible. Nationwide data, however, indicates that thetime to reach patients and the time required for hospital admittance continue to lengthen (Fig. 5). Multiple factors related to these increased delays have been identified at ambulance dispatch points, scenesof injury, and at hospitals, and measures have been taken to address each, but currently, effective solutions have not yet been found.
The Tokyo Fire Department has experienced an increase in the number of ambulance dispatch
incidents, and so has increased its number of emergency crews to meet with increased regional populations and demands for appropriate emergency care (Fig. 6). Nonetheless, the number of dispatches per
ambulance crew has not decreased; indeed, the number has increased from 1,488 in 1963 to 3,183 in
2013. There are a number of factors behind this increase, including increased reliance on ambulances for
relatively minor situations, increased emergency service requests from the elderly, changes in disease94｜Theory

trends, increased elderly
population, and physiological characteristics ofthe elderly. These trends
are similar across Japan,
and due to the increased
elderly population, about
40% of emergency patient transport is now forpatients aged 70 years orolder.
Changes in bloodpressure or state of con-

Minutes
45
40
35
30
25

Time from alert
to arrival on site

20

Time from alert
to hospital admission

15
10
5
0

2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Year

Figure 5. Trends in arrival time and time to hospital admission
1000s of requests
800

sciousness in the elderly, 700
which can rapidly wors- 600
en due to the effects of 500
medication or difficulty 400
Emergency carerequests
in maintaining homeo- 300
stasis, can in many cases 200
b e a l l e v i at e d s i mp l y 100
0through body position
1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013 Yearadjustments or observaFigure 6. Trends in number of emergency care requests in Tokyo
tion over time. In manycases, the situation improves during the wait for an ambulance to arrive, but the ambulance will often be used for transport toa hospital for examination, just in case. Unlike exogenous disease, inferring the prognostics of endogenous disease is considered difficult,3) and this difference is even more pronounced in the elderly. With
the goal of better optimizing ambulance usage, in 2007 the Tokyo Fire Department became the first inJapan to offer a telephone-based triage service for the general public, aiding in the determination ofwhether pathologies are sufficiently acute to warrant requesting emergency services. This service, called“#7119,”8) helped to lower the number of emergency requests in 2008, but by 2013, numbers were again
increasing. This illustrates the difficulty of restraining the number of incidents, given that emergency
medical care is viewed as an administrative service.

9.4

Driving and healthOperating an automobile requires skillful judgment and operation on the part of drivers. It is thus inappropriate to drive while impaired due to the influence of fatigue, illness, alcohol, or drugs.

Chapter 9: Traffic safety and medicine｜95

Illnesses that can affect automobile operation can be broadly classified into two types: chronic illness that is likely to hinder vehicle operation, and acute illness that can cause sudden death of the driver.
The Japanese Road Traffic Act and other enforcement orders classify illnesses that can hinder vehicle
operation as follows: 1) Schizophrenia with symptoms of hallucinations (excluding individuals that do
not exhibit symptoms that prevent any one of the abilities required for safe vehicle operation, such as
perception, prediction, decision-making, and operational control); 2) Epilepsy (excluding individuals inwhom there is no risk of seizure recurrence, those in whom seizure recurrence does not result in movement disorders or impaired consciousness, and those in whom seizure recurrence occurs only during
sleep); 3) Recurrent syncope (defined as disease that results in disturbance of consciousness due to transient ischemia of the whole brain, for which there is a possibility that episodes may recur); 4) Hypoglycemia unawareness (excluding individuals who are able to artificially modulate blood sugar); 5) Manic
depression (including mania and depression, but excluding individuals that do not exhibit symptoms
that prevent any one of the abilities required for safe vehicle operation, such as perception, prediction,
decision-making, and operational control); 6) Sleep disorders with symptoms of severe drowsiness; 7)
Other illnesses that involve symptoms that prevent any one of the abilities required for safe vehicle operation, such as perception, prediction, decision-making, and operational control; and 8) Dementia.
These illnesses can hinder vehicle operation present a risk of injury to others, and thus acquisition
and renewal of driver’s licenses is restricted for affected persons. Operation of automobiles by persons
with chronic disease that causes episodes of impaired consciousness can result in the occurrence of serious accidents. Therefore, the Road Traffic Law establishes that 1) persons acquiring or renewing driver’s
licenses are required to respond to a questionnaire related to symptoms of certain diseases, 2) physicians
who have diagnosed persons as having certain diseases that they feel may increase their chances of being
involved in a serious accident may elect to submit forms stating such, and 3) persons suspected of having certain diseases can immediately have their driver’s license provisionally revoked.9)
Sudden death is defined as the unexpected death of an otherwise healthy individual within 24 h ofonset of an endogenous disease, and is most commonly due to cardiovascular disease such as myocardial infarction, cardiomyopathy, aortic aneurysm rupture, aortic dissection, cerebral aneurysm rupture,and hypertensive cerebral hemorrhage. Such disease can sometimes occur suddenly while driving, butwhile they can result in death of the driver, in most cases the driver is able to retain sufficient functioning to stop the car by the side of the road after onset, and thus they rarely result in the death of passengers or pedestrians. There are, however, cases in which sudden onset results in driver incapacitation,
thus leading to a fatal traffic accident. Early diagnosis of underlying disease during standard healthexaminations and rapid treatment are therefore important for preventing sudden death while driving,which is classified as death by disease instead of by traffic accident. In cases where sudden death whiledriving is suspected, the cause of death is investigated, because distinguishing between such causes andlack of attention is important for elucidation of the cause of the accident and the dignity of the deceased.
Because alcohol impairs judgment and hinders vehicle operation, and can thus lead to traffic accidents, driving under the influence of alcohol is prohibited. In Japan, drunk driving is defined as operating an automobile with a blood alcohol concentration of 0.3 mg/mL or more, or with a breath alcohol

96｜Theory

Table 2. Relation between blood/breath alcohol concentration and drunkenness
Blood
Blood
BreathDrunkenness
concentration concentration concentration(mg/mL)(%)(mg/L)
Stage 0:
0.1–0.5
0.01–0.05
0.05–0.25 Euphoria: Feeling slightly intoxicatedStage 1:
0.5–1.0
0.05–0.1
0.25–0.5 Mild drunkenness: Mild cognitive disturbanceStage 2:
1.0–1.5
0.1–0.15
0.5–0.75 Light drunkenness: Cheerfulness, talkativeness, excitement
Moderate drunkenness: Lowered decision-making, lowered ability
Stage 3:
1.5–2.5
0.15–0.25
0.75–1.25
to walk
Stage 4:
2.5–3.5
0.25–0.35
1.25–1.75 Strong drunkenness: Slurred speech, clouded consciousness
Stage 5:
3.5–4.5
0.35–0.45
1.75–2.25 Stupor: Loss of consciousness, hypothermia
Stage 6:
4.5–
0.45–
2.25–
Coma: Cardiac dysfunction, respiratory paralysis, death

concentration of 0.15 mg/L or more (breath alcohol concentration is taken as approximately 1/2000 thatof blood alcohol concentration). In contrast, driving under the influence of alcohol is defined as driving
in a situation where alcohol consumption may prevent normal automobile operation, regardless of bloodor breath alcohol concentration. The relation between drunkenness and the degree of blood or breath
alcohol concentration is important for determination of driving ability at the time of an accident (Table2). Blood alcohol levels peak 1–2 h following consumption, then exhibit a gradual, linear decline as alcohol is metabolized. Maximum blood concentration increases with the amount of alcohol consumption,
but the rate at which alcohol can be metabolized is fixed (a decrease of 0.16 mg/mL per hour), so large
amounts of alcohol consumption will result in residual blood alcohol persisting over an extended time.
It is therefore sometimes the case that one believes oneself sober the morning after heavy drinking, but
in fact residual blood alcohol results in driving under the influence of alcohol. Note that in cases of hitand-run accidents where alcohol concentrations could not be measured at the time of the accident, concentrations can be still estimated according to a mathematical equation, based on the amount of alcohol
consumed or alcohol concentrations at a later time.10)
Other substances frequently abused in Japan, such as solvents, stimulants, and narcotics, can also
act on the brain to lower decision-making abilities and prevent normal driving, and there have been
accidents where solvents and stimulants have led to traffic accidents. There has been an increase in theabuse of dangerous drugs, and in the future it will likely be necessary to develop tests to screen for theuse of illegal drugs, such as stimulants and dangerous drugs, by drivers involved in traffic accidents.
Thorough implementation of such screenings would likely have a deterrent effect on driving while under
the influence of illegal drugs, which can result in fatal traffic accidents.

9.5

Traffic safety and sleep

9.5.1 Two major factors pertaining to sleep and safe driving
Safe driving requires appropriate perception, decision-making, and control, three operational abilities

Chapter 9: Traffic safety and medicine｜97that are disturbed by drowsiness. Good sleep is essential to preventing drowsiness.11), 12), 13)
A good understanding of accidents due to drowsiness calls for some fundamental backgroundknowledge. Among other things, there are two major sleep-related factors that have an effect. One is thehuman body’s circadian (internal) clock.14) The circadian clock functions to regulate daily rhythms
through various bodily functions such as temperature and hormone control, and its effects on operational ability increase from morning until night. The effects then decrease to a minimum in the earlymorning, after which they begin to rise again (Fig. 7A).
The other factor is the duration of time spent awake.15), 16) Operational ability worsens as the time ofcontinual wakefulness increases (Fig. 7B). Shortening the period of continual wakefulness by sleeping or
napping can thus inhibit worsening of operational ability.
Interaction occurs between the effects of the circadian clock and time spent awake, which determines the actual level of operational ability. As an example, Fig. 7C shows the results of an experimentin which response time was measured after 36 h of being continually awake (participants were asked topress a button as quickly as possible after viewing a light, or other visual stimulation).17) Pressing a button in response to visual stimuli corresponds well to extremely fundamental driving skills, such as braking when seeing a red signal or using the steering wheel to avoid a stopped car. This data makes it easy
to see that driving from late night to early morning or for long periods of time makes accidents more
likely.
Change due to circadian rhythmWorse

10 16 22→4

10 16 22

Change due to time awake

10 16 22

10 16 22

10 16 22B

4

10 16 22 (time of day)
20

C

＋

15

＝

10
5

←

Better0

6 12 18 24 30 36

0

6 12 18

24 30 360

6 12 18

Response errors (times)

Operational ability

A

4

Change due to combination of A and B

0
24 30 36 (Time awake [h])Figure 7. Effects of circadian rhythmicity and time awake on operational ability
The vertical axis represents the number of errors (lapses) in a reaction time test; C: Dots and black lines show measured values, gray lines are fitted according to A
and B

In addition to the circadian clock and time spent awake, the amount and quality of sleep before
driving are also closely related to safety. Not only sleep deprivation before automobile operation, butalso chronically short sleep, increases the risk of traffic accidents. 18), 19) Lowered quality of sleep often
occurs due to environmental conditions such as noise or high temperature,20) work- or family-related
stress,21) disorders such as insomnia or sleep-related breathing disorders,22) or other illnesses including
depression or back pain.23) Such sleep quality-related problems increase the likelihood of traffic accidents.24), 25) Furthermore, the use of medications that can result in drowsiness should be avoided whendriving.26)

98｜Theory

Sleep-related problems may lead to traffic violations that can then cause motor vehicle crashes.
Short sleep duration has been found to increase the frequency of driver inattention,27) and a group of
sleep apnea patients was shown to commit more stopping violations than did a control group.28)
9.5.2 Significance of sleep in traffic safety measures
Traffic safety can be ensured using several approaches. As described above, sleep and sleep-related problems have a large effect on drivers, and thus there is a critical need for establishing effective measures toimprove drivers’ sleep by sharing knowledge regarding proper sleep among drivers and their families
and employers, and also by developing workplace-based and other organizational programs for adequate
sleep.29)

References
1) Traffic Bureau, National Police Agency. 2014. Heisei 25 nen chu no kotsu jiko no hassei jokyo [Traffic accident situation 2013].
(in Japanese)2) Kibayashi, K., R. Shimada, and K. Nakao. 2013. “Temporal and Regional Variations in Accidental Deaths of Elderly People
in Japan.” Medicine, Science and the Law 53: 172–176.
3) Payne-James, J., R. Jones, S. B. Karch, and J. Manlove. 2011. Simpson’s Forensic Medicine. 13th ed. Hodder Arnold.
4) Kibayashi, K., R. Shimada, K. Nakao, and A. Ro. 2012. “Analysis of pituitary lesions in fatal closed head injury.” American
Journal of Forensic Medicine and Pathology 33: 206–210.
5) Cowley, R. A., F. Hudson, E. Scanian, W. Gill, R. J. Lally, W. Long, and A.O. Kuhn. 1973. “An economical and proved helicopter program for transporting the emergency critically ill and injured patient in Maryland.” Journal of Trauma 13, 12:1029–1038.
6) Hondo, K., A. Shiraishi, S. Fujie, D. Saitoh, and Y. Otomo. “In-hospital trauma mortality has decreased in japan possibly due
to trauma education.” Journal of the American College of Surgeons 217, 5: 850–857.
7) Moriya, T., and K. Tanjoh. 2009. “Current status of emergency medical services and role of prehospital care.” IATSS Review
Vol. 34, No. 3: 260–269. (in Japanese)
8) Sakurai, A., N. Morimura, M. Takeda, K. Miura, N. Kiyotake, T. Shiahara, and T. Aruga. 2014. “A retrospective quality assessment of the 7119 call triage system in Tokyo: telephone triage for non-ambulance cases.” Journal of Telemedicine and Telecare. http://doi.org/10.1177/1357633X14536347.
9) Kibayashi, K., and H. Shojo. 2002. “Incipient Alzheimer’s disease as the underlying cause of a motor vehicle crash.” Medicine,
Science and the Law 42: 233–236.
10) Kibayashi, K, T. Sumida, H. Shojo, and M. Hanada. 2007. “Dementing diseases among elderly persons who suffered fatal
accidents: a forensic autopsy study.” American Journal of Forensic Medicine and Pathology 28: 73–79.
11) Mitler, M. M., M. A. Carskadon, C. A. Czeisler, W. C. Dement, D. F. Dinges, and R. C. Graeber. 1988. “Catastrophes, sleep,and public policy: consensus report.” Sleep Vol. 11, No. 1: 100–109.
12) Åkerstedt, T. 2000. “Consensus statement: fatigue and accidents in transport operations.” Journal of Sleep Research Vol. 9, No.
4: 395.
13) Folkard, S., D. A. Lombardi, and P. T. Tucker. 2005. “Shiftwork: safety, sleepiness and sleep.” Industrial Health Vol. 43, No. 1:
20–23.
14) Golombek, D. A., and R. E. Rosenstein. 2010. “Physiology of circadian entrainment.” Physiological Reviews Vol. 90, No. 3:
1063–1102.
15) Cajochen, C., S. B. Khalsa, J. K. Wyatt, C. A. Czeisler, and D. J. Dijk. 1999. “EEG and ocular correlates of circadian melatoninphase and human performance decrements during sleep loss.” American Journal of Physiology Vol. 277, No. 3 Pt. 2:
R640–649.
16) Dawson, D., and K. Reid. 1997. “Fatigue, alcohol and performance impairment.” Nature Vol. 388, No. 6639: 235.
17) Van Dongen, H. P., A. M. Bender, and D. F. Dinges. 2012. “Systematic individual differences in sleep homeostatic and circadian rhythm contributions to neurobehavioral impairment during sleep deprivation.” Accident Analysis & Prevention Vol. 45
Suppl.: 11–16.

Chapter 9: Traffic safety and medicine｜9918) Dawson, D., and K. McCulloch. 2005. “Managing fatigue: it’s about sleep.” Sleep Medicine Reviews Vol. 9, No. 5: 365–380.
19) Dorrian, J., M. Sweeney, and D. Dawson. 2011 “Modeling fatigue-related truck accidents: Prior sleep duration, recency andcontinuity.” Sleep and Biological Rhythms Vol. 9, No. 1: 3–11.
20) Kayaba, M., T. Ihara, H. Kusaka, S. Iizuka, K. Miyamoto, and Y. Honda. 2014. “Association between sleep and residential
environments in the summertime in Japan.” Sleep Medicine Vol. 15, No. 5: 556–564.
21) Takahashi, M., K. Iwasaki, T. Sasaki, T. Kubo, I. Mori, and Y. Otsuka. 2012. “Sleep, fatigue, recovery, and depression after
change in work time control: a one-year follow-up study.” Journal of Occupational and Environmental Medicine Vol. 54, No.
9: 1078–1085.
22) Rosekind, M. R., and Gregory K. B. 2010. “Insomnia risks and costs: health, safety, and quality of life.” American Journal ofManaged Care Vol. 16, No. 8: 617–626.
23) Finan, P. H., and M. T. Smith. 2013. “The comorbidity of insomnia, chronic pain, and depression: Dopamine as a putative
mechanism.” Sleep Medicine Reviews Vol. 17, No. 3: 173–183.
24) Léger, D., V. Bayon, M. M. Ohayon, P. Philip, P. Ement, A. Metlaine, M. Chennaoui, and B. Faraut. 2014. “Insomnia and accidents: cross-sectional study (EQUINOX) on sleep-related home, work and car accidents in 5293 subjects with insomnia
from 10 countries.” Journal of Sleep Research Vol. 23, No. 2: 143–152.
25) Tregear, S., J. Reston, K. Schoelles, and B. Phillips. 2009. “Obstructive sleep apnea and risk of motor vehicle crash: systematic
review and meta-analysis.” Journal of Clinical Sleep Medicine Vol. 5, No. 6: 573–581.
26) Hetland, A., and D. B. Carr. 2014. “Medications and impaired driving.” Annals of Pharmacotherapy Vol. 48, No. 4: 494–506.
27) Anderson, C., and J. A. Horne. 2013. “Driving drowsy also worsens driver distraction.” Sleep Medicine Vol. 14, No. 5:
466–468.
28) Vakulin, A., P. G. Catcheside, C. J. Van Den Heuvel, N. A. Antic, R. D. McEvoy, and S. D. Baulk. 2011. “Increased rate of traffic law infringements during on-road metropolitan driving in obstructive sleep apnea patients.” Sleep and Biological Rhythms
Vol. 9, No. 3: 144–149.
29) Takahashi, M. 2012. “Prioritizing sleep for healthy work schedules.” Journal of Physiological Anthropology Vol. 31, No. 1: 1–8.
Recommended Reading
1) Bloomberg, H., B. Svennblad, K. Michaelsson, L. Byberg, J. Johansson, and R. Gedeborg. “Prehospital trauma life support
training of ambulance caregives and the outcomes of traffic-injury victims in Sweden.” Journal of the American College ofSurgeons 217, 6: 1010–1019.e2.
2) Czeisler, C. A. 2013. “Perspective: casting light on sleep deficiency.” Nature Vol. 497, No. 7450: 13.
3) Takahashi, M. 2014. “Assisting shift workers through sleep and circadian research.” Sleep and Biological Rhythms Vol. 12 (2):85–95. http://doi.org/10.1111/sbr.12065.
4) Williamson, A., R. Friswell, J. Olivier, and R. Grzebieta. 2014. “Are drivers aware of sleepiness and increasing crash risk whiledriving?” Accident Analysis & Prevention 70: 225–234. http://doi.org/10.1016/j.aap.2014.04.007.
5) Ayas, N., R. Skomro, A. Blackman, K. Curren, M. Fitzpatrick, J. Fleetham, C. George, T. Hakemi, P. Hanly, C. Li, et al. 2014.
“Obstructive sleep apnea and driving: A Canadian Thoracic Society and Canadian Sleep Society position paper.” CanadianRespiratory Journal Vol. 21, No. 2: 114–123.
6) Strohl, K. P., D. B. Brown, N. Collop, C. George, R. Grunstein, F. Han, L. Kline, A. Malhotra, A. Pack, B. Phillips, et al. 2013.
“An official American Thoracic Society Clinical Practice Guideline: sleep apnea, sleepiness, and driving risk in noncommercial drivers. An update of a 1994 Statement.” American Journal of Respiratory and Critical Care Medicine Vol. 187, No. 11:
1259–1266.
Practical application projects for reference
Addressing issues associated with prehospital emergency transportation: 176–179
Dissemination and promotion of screening for sleep disorders: 180–183

Chapter10

Laws and policies
pertaining to traffic safety
This chapter focuses on laws and policies pertaining to traffic safety, provides basic information, anddiscusses issues to overcome for better future institutional design and implementation. More specifically,
Section 10.1 provides an overview of the roles of laws and the legal framework for traffic safety, followedby discussions on developments in policies concerning traffic safety (Section 10.2), traffic safety regulation from the perspective of criminal law (Section 10.3), and the relationship between new traffic safety
technologies and legal policy (Section 10.4). Section 10.5 provides a summary of this chapter, reviewing
legal policies on traffic safety in light of recent active legal discussions on risk management.

10.1

The roles of laws and legal framework for traffic safety

10.1.1 Laws and securing transportation and safety: An overview of the relevant laws
and legal framework
Securing safe transportation for the public has been a major responsibility of any country throughout
history. Herbert Krüger (1905–89), a German scholar of public law, considered roads as an essential factor in a country’s existence.1) Today, the importance of international transportation has been rapidly
increasing, and countries have taken various measures to secure safety in international transportation,
signing treaties such as the International Convention for the Safety of Life at Sea (the SOLAS Convention) and the Convention on International Civil Aviation (the Chicago Convention).
In Japan, too, securing means of transportation and its safety is now a national issue as seen inefforts to secure mobility for the transportation-disadvantaged, such as senior citizens, and in countermeasures to dangerous bicycle riding. Since Japan is a nation of laws, its efforts to fulfill its duty in dealing with such issues must be rooted mainly in laws and regulations. In particular, when actions taken inthis process restrict the rights and freedoms of citizens and impose obligations on them, these actions
must be based on laws and regulations (horitsu and jourei).
Let us consider road traffic as an example. The Road Traffic Act (doro kotsu ho) enacted in 1960 isaimed at preventing dangers on the road, promoting the safety of other traffic and its smooth flow, andChapter 10: Laws and policies pertaining to traffic safety｜101

contributing to the prevention of obstacles due to road traffic (Article 1). The act contains provisions on
the ways in which pedestrians and vehicles move, the driver’s license system, and penalties and fines forviolations. The Road Traffic Act is the most important law regarding road traffic rules, and based on thislaw, the National Public Safety Commission and the National Police Agency, as well as prefectural public
safety commissions and police forces, conduct administrative activities related to road traffic safety. 2)
The law governing the construction and maintenance of road networks and the structure of roads is theRoad Act (doro ho). The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has jurisdiction concerning this law, and the national, prefectural, and municipal governments perform theirrespective responsibilities in securing the safety of roads as physical infrastructure. Therefore, if an accident occurs due to a falling object from an overpass or the roof of an aging tunnel, the relevant government implementing the law may be held responsible for failure in road management (in, for example, acompensation lawsuit against the national government). However, in cases of traffic accidents caused by
improper installation of traffic lights or damage caused to a third party due to unnecessary or inappropriate pursuit of a violating vehicle by a police car, the relevant police agency may be held responsible
with regard to its authority or its acts or omissions. The driver’s license system governed by the Road
Traffic Act specifies a general mechanism for checking the aptitude of those who intend to drive an automobile. As for the people and companies whose business involves driving vehicles such as buses andtaxis, the Road Transportation Act (doro unso ho), as a law regulating business operations, provides thebasis for a separate mechanism of safety regulation (operations in the trucking business are regulated by
the Trucking Business Act [kamotsu jidosha unso jigyo ho]). The law requires these business operators,
among other things, to set safety management rules and have operations managers. For example, in
response to the serious accident involving an express tour bus caused by an overworked driver on April
29, 2012, the MLIT revised the interpretation and implementation standards for the Ordinance for
Enforcement of the Road Transportation Act, which led to strengthened regulations including restrictedtravel distances and the presence of a second driver.3)
10.1.2 Problems requiring multifaceted solutions and the division andcomprehensiveness of administrative authority
As the overview presented above suggests, the laws governing transportation and its safety have the following characteristic: matters subject to relevant rules are divided according to the jurisdiction of different agencies (and their departments). In a sense, this division is needed by the administrative agencies
and their activities because agencies have pursued specialization in order to respond to various administrative issues and their increasing difficulty. In addition, issues involving traffic safety do not arise conveniently according to the configuration of government agencies and thus often require cross-agency
measures. For example, responses to the negative health effects of road-related pollution include not
only creation of planting strips and installation of sound barriers by organizations responsible for constructing and managing roads, as well as the construction of underground roads, but also measures thattreat automobile transportation as a source of pollution, such as exhaust gas regulations, road pricing,and road closure in cases of emergency. See, for example, the Supreme Court judgment for the Route 43

102｜Theory

lawsuit (July 7, 1995; Supreme Court Reports [Civil Cases] (Minshu), vol. 49, no. 7, p. 1870), the Tokyo
District Court judgment for the Tokyo air pollution lawsuit (October 29, 2002; Law Cases Reports(Hanreijiho), no. 1885, p. 23), and other judicial precedents regarding road-related pollution.4)
It is therefore important that comprehensive and consistent measures be formulated through talks
among government agencies that have jurisdiction over different laws and through arrangements madeby coordination bodies such as the Cabinet Secretariat and the Cabinet Office. Also, municipal governments, which are closest to the sources of problems and have comprehensive authority over local administrative issues including community development, are crucial actors in regard to legal policy for traffic
safety. To implement measures incorporating the ideas devised by municipal and prefectural governments that have firsthand experiences of problems, in the second phase of Japan’s decentralization
reform, the laws and legal framework concerning roads and traffic safety were reexamined to a certain
extent with respect to the requirements and limitations imposed by the national government, as seen in
the permission of the use of own technical standards by municipal and prefectural governments withregard to the structure of roads, the abolishment of mandatory traffic safety planning by municipal governments, and the requiring of efforts for such planning.5)
With respect to the issue of traffic safety, the role of regulations set by regional and local governments is larger than it was in the past. Although various stakeholders have become involved, it is desirable that local residents increase their participation in the planning of traffic safety measures related tocommunity development.

10.2

Implementation of traffic safety policies

This section discusses information dissemination, quality assurance, and utilization of non-life insurance which, like legal restrictions, play important roles as policy instruments for securing traffic safety.
This section also considers international harmonization of automobile safety standards to show thegrowing importance of having an international perspective in traffic safety issues.
10.2.1 Information dissemination: The Japan New Car Assessment Program
Providing information is becoming an important policy instrument in various fields. A new car assessment program is a policy instrument in which information on the performance of automobile technologies is made public in order to promote development of automobile technologies by automobile manufacturers and proper selection of technologies by automobile users. New car assessment can beconsidered as a type of technological assessment. As a policy instrument, technological assessment supports decision-making through dissemination of information regarding various impacts of technologies.6) These impacts include not only safety risks and economic costs, but also social and cultural
impacts. In this broader context, new car assessment is conducted with a focus on the safety performance of automobile technologies. The Japan New Car Assessment Program started in 1995, and initially emphasis was put on providing information about crash safety performance. Subsequently,

Chapter 10: Laws and policies pertaining to traffic safety｜103

information on the performance of pedestrian protection functions and child safety seats began to beprovided. Today’s new car assessment also covers preventive safety technologies.
10.2.2 Quality assurance: Assessment of transportation safety management
As technologies are rapidly advancing and being utilized in organizations, it is often difficult to ensure
safety solely based on regulations that are distinct from each other. In such situations, there are ways togive rise to quality assurance that is achieved through business operators’ voluntary efforts for improvement. Quality assurance by an organization refers to guaranteeing product quality to its customers bymaintaining in-house communications intended for product quality improvement. For this purpose,organizations are expected to act proactively and autonomously and in a well-organized manner. Thisapproach to quality assurance has been widely used in various fields including nuclear safety, medical
safety, and food safety.
In the transportation sector, with consideration given to accidents such as the JR West Fukuchiyama Line accident of April 2005, the Japanese government began its efforts to introduce a mechanismthat would check the entire quality assurance system of all transportation business operators including
railway operators.7) A committee for examining preventive measures against public transportation accidents attributed to human error was created in June 2005, and an interim report was published inAugust. The report pointed out that to create a climate or culture of safety, it would be important for abusiness operator to create its own safety management system and to make a continual commitment tosafety. The Omnibus Transportation Safety Bill stipulated the creation of a safety management system bybusiness operators and, on the government side, the establishment of a safety monitoring body responsible for different modes of transportation and the creation of a transportation safety management system that would perform, among other things, safety management assessment. The bill also required
business operators to prepare and submit their safety management rules and to appoint a general manager on safety and report the appointment. The safety monitoring body was mandated to assess business
operators’ transportation safety management systems. The results of such assessment are summarized
for different modes of transportation (e.g., railway, automobile, sea transportation, and aviation) and areused as feedback for actual business operations.
10.2.3 Non-life insurance: Compulsory insurance and voluntary insurance
Non-life insurance not only secures compensation to victims of accidents and reduces feelings of insecurity at the societal level, but also has a preventive function in which accidents and damage are curbed
because of insurance premium discounts/surcharges and other measures that adjust to hazards associated with the insured parties or properties.8)
For automobile accidents, the need for comprehensive compensation coverage is high because
many people are potential victims of accidents. Without such coverage, it would have been difficult to
introduce into society the technology called the automobile, which inevitably would produce a certain
number of victims.
In Japan, there are two kinds of automobile insurance: compulsory insurance (automobile liability

104｜Theory

insurance/mutual aid) based on the Automobile Liability Security Act and voluntary insurance (automobile insurance/mutual aid). On the basis of automobile liability insurance and mutual aid, voluntary
private insurance provides extra coverage. There is also the Automobile Liability Security Program inwhich the government provides compensation to victims of accidents caused by uninsured vehicles. The
government initially provided reinsurance for 60% of automobile liability insurance in order to ensurecompensation, but the government reinsurance program was abolished in 2002 due to the improved
business foundation of insurance companies. The deregulation of the insurance industry that began in1998 enabled companies to set their premiums independently, and they started to sell products that offer
premium discounts for cars with high safety performance. As for voluntary insurance, incentive systems
are implemented in which premiums change according to past driving history, and the resulting differences in premiums are expected to curb the number of accidents.
10.2.4 International harmonization of standards: The World Forum for Harmonization of
Vehicle Regulations
Since automobiles are important in trade and direct investment, countries had incentives to internationally harmonize technical standards associated with safety and other factors.9) The United States and theEuropean Union created the Trans-Atlantic Business Dialogue in 1995 in a move toward mutual recognition of standards, and its main theme was harmonizing recognition of automobile-related standards.
Subsequently, discussions were held in a trilateral group that included Japan, and progress was made inindustry-led harmonization.
Against the background of this trend toward harmonization of standards, Working Party 29 of theUnited Nations Economic Commission for Europe, which was a Eurocentric intergovernmental commission, was rediscovered and started to play an important role in internationally harmonizing standards for automobile technologies. In 1999, Working Party 29 began to be called the World Forum for
Harmonization of Vehicle Regulations. While this was happening, progress was made in international
harmonization of individual items: the 1958 Agreement concerning mutual recognition of automobile
technology standard certifications was revised in 1995, and a global agreement was adopted in 1998
among countries including Japan, the United States, and the European Union. For Japan, such international harmonization constituted one aspect of its international industrial policy.

10.3

Criminal regulations regarding traffic safety10)–14)

10.3.1 Characteristics of criminal regulations: comparison of criminal penalties andpublic-order penalties
To secure traffic safety, violators of transportation-related laws and regulations may receive criminal
penalties. In other words, violations of such laws and regulations are not only subject to public-order
penalties (fines), but also considered to constitute a crime. Therefore, there is a system in which such
violations are legally condemned by imposing criminal penalties on the violators (criminals) with theChapter 10: Laws and policies pertaining to traffic safety｜105

aim that the same violations are prevented from recurring.
Similar to criminal penalties, public-order penalties (for disturbing order in the functioning of government administration) are legal sanctions against failure to comply with certain requirements (i.e.,requirements regarding certain acts and omissions that contribute to achievement of traffic safety), butthere are qualitative differences in the extent of sanctions between these two types of penalties. Both ofthem render adverse dispositions to violators, but criminal penalties provide the opportunity for strong
legal condemnation of violators’ actions. Accordingly, violators who receive a criminal penalty will havea criminal record and must accept various disadvantages, such as certain license restrictions, according
to the severity of the criminal offence. For example, people driving an automobile over the speed limit
would just pay a fine if the seriousness of the violation is within a certain range (e.g., a speed less than 30
km/h above the legal speed limit); however, if the violation is more serious (e.g., a speed equal to or
greater than the abovementioned threshold), it would result in a fine as a criminal penalty and in a criminal record (entry in the offender list).
10.3.2 Criminal regulations pertaining to traffic safety(1) Relevant laws and regulations
The criminal regulations pertaining to traffic safety are mainly based on the Road Traffic Act and the
Act Concerning Punishment of Automobile Driving Resulting in Death or Injury (jidosha unten shisho
koi shobatsu ho). The latter is an independent law that was created to define the crime of dangerous driving resulting in death or injury (kiken unten chishisho zai) and the crime of negligence in automobile
driving resulting in death or injury (jidosha unten kashitsu chishisho zai), which had been defined in the
penal code.(1)(2) The Road Traffic Act
Main violations under this law, for which criminal penalties would be imposed, are listed in Table 1.
(3) The Act Concerning Punishment of Automobile Driving Resulting in Death or Injury
Main violations under this law, for which criminal penalties would be imposed, are listed in Table 2.
10.3.3 An example of applying the law
The following is an example of how the various penalties mentioned in Section 10.3.2 are applied.
Suppose Person A drove a car to a bar, and after drinking he tried to drive the same car home.
When he got in the car, he was slightly drunk but remembered that he was sitting in the driver’s seat andstarted the car (that is, normal operation of the vehicle would have potentially been impaired, but was
not difficult). After that, while driving he lost consciousness due to intoxication (that is, normal operation of the vehicle became impossible). He therefore became unable to properly drive the car, and thecar hit and killed a pedestrian. When this occurred, Person A regained consciousness but did not call
(1) The law was enacted in November 2012 and was implemented on May 20, 2013.

106｜Theory

Table 1. Main violations for which criminal penalties would be imposed under the Road Traffic Act
Crime

Typical caseStatutory penalty

Legal basis(2)Failure to drive safely

Inattentive driving, etc.

Imprisonment for up to 3 months, ora fine of up to 50,000 yen

Article 70; Article 119, No. 9

Fatigued driving

Drowsy driving, etc.

Imprisonment for up to 3 years, or afine of up to 500,000 yen

Article 66; Article 117, Section 2-2,
No. 7

Speeding

Violation of the speed limit

Imprisonment for up to 6 months, ora fine of up to 100,000 yen

Article 22; Article 118, No. 1

Driving under the
influence of alcohol

Slightly drunk

Imprisonment for up to 3 years, or afine of up to 500,000 yen

Article 65, Paragraph 1; Article 117,
Section 2-2, No. 3

Providing alcohol

Providing alcoholic beverages to those who
may drive under the influence of alcohol

Imprisonment for up to 2 years, or afine of up to 300,000 yen

Article 65, Paragraph 3; Article 117,
Section 3-2, No. 2

Drunk driving

Drunken staggering

Imprisonment for up to 5 years, or afine of up to 1 million yen

Article 65, Paragraph 1; Article 117,
Section 2, No. 1

Providing alcohol

Providing alcoholic beverages to those who
may engage in drunk driving

Imprisonment for up to 3 years, or afine of up to 500,000 yen

Article 65, Paragraph 3; Article 117,
Section 202, No. 5

Failure to report an
accident

Failure to report an accident to the police

Imprisonment for up to 3 months, ora fine of up to 50,000 yen

Article 72, Paragraph 1, 2nd part;
Article 119, No. 10

Failure to provide aid

Failure to aid the injured

Imprisonment for up to 10 years, ora fine of up to 1 million yen

Article 72, Paragraph 1, 1st part;
Article 117

Table 2. Main violations for which criminal penalties would be imposed under the Act Concerning Punishment ofAutomobile Driving Resulting in Death or Injury
Penalty including that for unlicensed
drivingLegalbasis(3)Imprisonment for up to 15 years

Imprisonment for 6 months to 20
years

Article 2

Impaired operation of
the vehicle, resulting
in death

Imprisonment for 1 year to 20 years

Imprisonment for 1 year to 20 years(no additional penalty)

Article 2

Dangerous driving resulting ininjury (less severe offense)

Potential impairment
of normal operation,
resulting in injury

Imprisonment for up to 12 years

Imprisonment for up to 15 years

Article 3

Dangerous driving resulting indeath (less severe offense)

Potential impairment
of normal operation,
resulting in death

Imprisonment for up to 15 years

Imprisonment for 6 months to 20
years

Article 3

Avoiding detection of theinfluence of alcohol or otherintoxicants in negligent driving
resulting in death or injury

Negligent driving +death or injury + water
intake, etc.

Imprisonment for up to 12 years

Imprisonment for up to 15 years

Article 4

Negligent driving resulting indeath or injury

Negligent driving +death or injury

Imprisonment for up to 7 years, or afine of up to 1 million yen

Imprisonment for up to 10 years

Article 5

Unlicensed driving

Penalty for unlicensed driving added
to the statutory penalty listed above(see the column “Penalty includingthat for unlicensed driving”)

The penalty for driving without alicense varies by crime (as seen in
Article 6
the difference between the entries
in this column and in the left column)

Crime

Typical case

Dangerous driving resulting ininjuryImpaired operation of
the vehicle, resulting
in injury

Dangerous driving resulting in
death

Additional penalty due tounlicensed driving

Statutory penalty(2) The relevant segments listed are those of the Road Traffic Act.
(3) The relevant segments listed are those of the Act Concerning Punishment of Automobile Driving Resulting in Death or Injury.

Chapter 10: Laws and policies pertaining to traffic safety｜107

the police out of fear. He was drinking copious amounts of bottled water at the scene of the accident
when he was arrested by dispatched police officers. After the arrest it became clear that his driver’s
license had already expired.
In this case, Person A is guilty of driving under the influence of alcohol, driving without a license,
failure to report an accident, and failure to provide aid (all of which are crimes under the Road TrafficAct), as well as dangerous driving resulting in death or injury (or a less severe version of it; Article 3 of
the Act Concerning Punishment of Automobile Driving Resulting in Death or Injury; the crime of driving without license under Article 6 of the Act also applies). With regard to the fact that his act of drinking water hindered accurate measurement of blood alcohol level, he is guilty of avoiding detection of theinfluence of alcohol or other intoxicants in negligent driving resulting in death or injury (Article 4 of the
Act).

10.4

New traffic safety technologies and legal policy

This section examines judgments made from a legal policy standpoint with regard to how various newtechnologies that people adopt for increased convenience as participants in road traffic can be incorporated into the system of traffic safety rules. Let us look at a few examples. An example of a technologythat provides assistive power to people who rely on human power to move from one place to another isthe electric wheelchair, which enables those who cannot walk by themselves to move on streets as pedestrians. That is, they are separated from automobiles and share sidewalks with other pedestrians who areon foot. Since electric wheelchairs share space with people on foot, securing safety becomes an issue.
The current system of rules deals with this issue by setting certain standards regarding the speed andshape of electric wheelchairs and permitting those that comply with the standards to share streets withpedestrians (see Supplemental Material 1 on the next page). Also, with regard to electric wheelchairusers, as long as their wheelchairs satisfy these standards, they can operate their wheelchairs without
being examined for their ability and aptitude to do so, unlike in the case of automobiles.(4)These judgments in terms of legal policy are expressed in a provision of the current law stipulatingthat electric wheelchairs are treated as pedestrians for the purpose of applying the law.(5) Important components of the current system of traffic safety rules are a mechanism that distinguishes between the different ways in which roads are used, according to the types of participants in road traffic (e.g., pedestrians, bicycles, and automobiles) and a mechanism that examines the ability and aptitude of those who
operate transportation machines such as automobiles. In both aspects, electric wheelchair users enjoy
the same convenience provided by the law to the pedestrians. Electric-power-assisted bicycles also provide supplemental power to humans riding them, and those that satisfy certain standards are treated as(4) According to the definition in the law, electric wheelchairs are not regarded as automobiles or motorized bicycles (Road Traffic Act,
Article 2, Paragraph 1, Nos. 9 and 10).
(5) Road Traffic Act, Article 2, Paragraph 3.

108｜Theory

Road Traffic Act, Article 2, Paragraph 1, No. 11-3 (definition of wheelchairs for the physically disabled)
It refers to a wheelchair that provides mobility to those with impaired walking due to a physical disability (motorized
wheelchairs must satisfy the standards set forth in the relevant Cabinet Office Ordinance).
Ordinance for Enforcement of the Road Traffic Act, Article 1-4, Paragraph 1 (standards for motorized
wheelchairs for the physically disabled)
With respect to Article 2, Paragraph 1, No. 11-3 of the law, the following standards are set by the relevant Cabinet
Office Ordinance.
1. The size of the wheelchair must be within the following dimensional limits.
a. Length: 120 cm
b. Width: 70 cm
c. Height: 109 cm
2. The structure of the wheelchair must satisfy the following conditions.
a. The motor must be an electric motor.
b. The speed of the wheelchair must not exceed 6 km/h.
c. The wheelchair cannot have any sharp protrusion which can potentially harm pedestrians.
d. The appearance of the wheelchair must be distinct from that of an automobile or motorized bicycle.
Supplemental Material 1. Definition of electric wheelchairs

bicycles along the same reasoning used in the case of electric wheelchairs (see Supplemental Material 2).
In the future, the use of devices that enable assisted walking and utilize relevant robot technologies (i.e.,
personal mobility devices) will emerge as a concrete issue.
Let us now consider technologies that assist drivers of automobiles in perceiving their surroundings, processing information, making judgments, and operating devices, all of which are necessary skills
in driving an automobile. These new technologies are very useful to drivers. The fact that they reduce
the risk of accidents by overriding driver errors is also socially significant. Many of these technologies
have already been commercialized as features available in automobiles. Also, assistive systems for safe
driving are put to practical use as part of efforts to develop intelligent transportation systems. A question then arises how these new technologies should be introduced into the system of traffic safety rules.
It has long been the case in Japan that people can obtain a restricted driver’s license that is only
valid for automatic transmission vehicles. There is also a special driver’s license that people who areunable to drive a regular automobile because of a disability of the arms or legs can obtain if they drive
an automobile equipped with assistive devices enabling proper driving operations. In these cases,
although the range of automobiles that can be legally driven is restricted, people using assistive technologies in performing necessary operations are not distinguished from regular drivers in terms of the freedom to drive an automobile on streets (e.g., where to drive and how to drive) or in terms of the responsibilities associated with participating in road traffic (e.g., the obligation to drive safely).
The current system of traffic safety rules requires drivers to assume many responsibilities, and drivers are subject to criminal or administrative penalties for their mistakes in driving. The driver’s licenseChapter 10: Laws and policies pertaining to traffic safety｜109

Road Traffic Act, Article 2, Paragraph 1, No. 11-2 (definition of bicycles)
A bicycle refers to a vehicle that is equipped with two or more wheels and is operated by human power with pedals
or hand cranks (vehicles running on rails are excluded) but is not a wheelchair for the physically disabled, not avehicle that assists walking, and not a vehicle for infants (bicycles with a motor for supplementing human powerthat satisfy the standards set by the relevant Cabinet Office Ordinance are included).
Ordinance for Enforcement of the Road Traffic Act, Article 1-3 (standards for bicycles with a motor for
supplementing human power)
With respect to Article 2, Paragraph 1, No. 11-2 of the law, the following standards are set by the relevant Cabinet
Office Ordinance.
1. The motor used for supplementing human power must satisfy all of the following conditions.
a. It is an electric motor.
b. When the bicycle is operated at less than 24 km/h, the ratio of human power to the power from the motor
intended to supplement human power must be equal to or less than the value listed for each of the speed
ranges shown in (1) and (2) below.
(1) Less than 10 km/h: 2(2) 10 km/h or more but less than 24 km/h: 2 - [speed (in kilometers per hour) - 10] / 7.
c. When the bicycle is operated at 24 km/h or more, the power from the motor intended to supplementhuman power must not be engaged.
d. The structure of the motor satisfying conditions a to c is such that it is difficult to make modifications
resulting in violation of any of conditions a to c.
2. The function of the motor intended to supplement human power must work smoothly, and the working of thefunction must not hinder safe operation of the bicycle.
Supplemental Material 2. Definition of electric-power-assisted bicycles

system provides a mechanism that excludes those who are not expected to fulfill such responsibilities.
These facts are attributed not only to the way in which the automobiles currently driven are designed—
they are designed to be operated by their drivers—but also to the freedom of movement in road transportation. People are free to choose when to move, where to move, and how to move, and the same
applies to their automobile driving as a means of movement. At the same time, however, people enjoying such freedom are responsible for the adverse outcomes that can potentially result from driving. Also,in road transportation, drivers are numerous, are mutually unknown to each other, and are potentially
dangerous to each other. Therefore, the fact that the drivers have uniform freedoms and uniform responsibilities makes situations in road transportation more predictable and increases people’s trust in roadtransportation as a social function.
As long as drivers’ freedom of movement is a given, the fact that new technologies reduce burden
on drivers does not immediately mean that their responsibilities are reduced. With regard to automateddriving systems, it makes sense, in terms of the legal framework, that relevant discussions are conductedalong similar lines so long as drivers’ freedom of movement is recognized. This framework is

110｜Theory

value-neutral, and we should put various values into practice in a harmonious manner based on it.

10.5

Legal policy concerning risk management

10.5.1 No one saw the danger
In order to secure traffic safety, various risk factors must be removed or controlled. In legal and policy
studies, researchers are exploring ways in which modern risks, as opposed to dangers in the traditional
sense which are qualitatively distinct, are handled, with consideration given to the trends in social system theory since the 1980s. Dangers in the traditional sense refer to those that can be expected based on
empirical rules and can be predicted and handled based on trial and error in experiments and based on
knowledge accumulated through experience. In contrast, risks in the modern context (those associatedwith genetic technology, nuclear technology, etc.) are characterized as follows: there has been little timeto accumulate knowledge through experience; consequences are difficult to predict; and uncertainties
are great. There are some problems in understanding the evolution from traditional dangers to modern
risks in a simple linear manner, but an accident that occurred in 1921 provides an opportunity to consider the relationship between dangers and risks.
BASF, a German company, had a plant that produced ammonia, and since 1913 it had produced
ammonia and nitrogenous fertilizer using a process called atmospheric nitrogen fixation (the Haber–
Bosch process). The fertilizer was piled up out in the open, and parts of the pile that hardened becauseof absorbed moisture were broken up using dynamite before shipment. This way of handling the fertilizer led to a catastrophic explosion on September 21, 1921, leaving 509 people dead, 160 missing, andmore than 1900 injured. The accident later became known as the Oppau explosion. Dynamite was used
repeatedly, about 30,000 times, without problems. Also, no question was raised regarding the way thefertilizer was stored. Moreover, laboratory experiments using samples had shown that nitrogenous fertilizer does not typically explode in the manner it did in the accident. The company, its employees,
neighborhood residents, and even experts did not expect such an accident.15), 16)
10.5.2 Government response to dangers and risks: The classic approach
To deal with dangers that are reasonably predictable, modern administrative laws have adopted certain
approaches to regulations and relevant mechanisms as described below. The starting point is individual
freedom. Individuals can act freely as long as they do not violate the rights and interests of others. The
national government intervenes in order to prevent harm resulting from individuals’ activities. The limits to such intervention are explicitly specified by laws. It is preferred that the government has less andless room for discretionary judgments.
Legislators use different legal mechanisms according to the need for regulation. For example, they
adopt a reporting system if activities subject to regulation are not very dangerous and if it suffices tohave information on these activities. In contrast, if the government needs to make specialized judgments
regarding whether an activity can be permitted, it use a license (permit) system in which the governmentChapter 10: Laws and policies pertaining to traffic safety｜111

conducts reviews and issues licenses (permits) under relevant laws that set abstract licensing standards.
In a license system, the national government and other entities monitor or supervise activities, issue recommendations or orders when dangers or harm arises, and, if no improvement is made, revoke thelicense.
The basic structure of such mechanisms and the ideas supporting it stem from an outdated notionthat legislators and administrators can not only recognize, in a centralized manner, the dangers posed tothe public by regulated enterprises, as well as the need for regulation, but also make specialized judgment. Here, difficulties in collecting information on regulated entities are not taken into account. Today’s
regulatory systems (e.g., the driver’s license system based on the Road Traffic Act) still have such structures across different areas of government administration. The same applies to regulatory reform initiatives and deregulation initiatives, except for those related to outsourcing and extreme cases in which
regulations are totally abolished.
10.5.3 Dealing with modern risks: The need for new organizations and approaches
The limitations of the traditional regulatory system become apparent when considering the risks associated with modern technologies including genetic engineering and nuclear power. It becomes important
to consider not only the practical side including issues like the uneven distribution of information andlimited government resources (human and physical) but also the legal side—how risk management systems can be designed and operated in the face of various uncertainties. The fact that proper risk management requires risk assessment conducted independently has been recognized in various areas (sometimes through painful experiences), and discussions have been held with regard to the ideal types oforganizations for performing risk assessment and approaches to risk assessment.17), 18)
From the standpoint of organizations and approaches for risk assessment, the following considers
the workings of the Japan Transport Safety Board (JTSB) in accident investigations and the issue involving the use of investigation information. In areas associated with traffic safety, some issues can be understood within the framework of traditional dangers, but there are new areas that require a new kind ofrisk assessment. Such new areas include automated driving systems and large-scale long-distance transportation systems utilizing linear-motor trains. Also, it must be considered whether traditional organizations and approaches can still deal with traditional dangers in transportation.
(1) JTSB: Investigation of causes and prevention of recurrence
In the case of transportation-related accidents, the law indirectly attempts to prevent their recurrence by
imposing penalties on those who cause an accident (see Section 10.3 for discussions on criminal liability) and by recognizing the right of victims to claim damages (see Sections 10.1 and 10.2 for discussions
on civil liability). At the same time, mechanisms to directly prevent recurrence of accidents are gradually becoming important. These mechanisms consist of various approaches and organizations that investigate the causes of accidents and propose measures to prevent their recurrence, independently from theissue of penalties and legal liability.
In Japan, the Aircraft Accident Investigation Committee was created in 1974 as a permanent112｜Theory

affiliate body of the then Ministry of Transport to investigate the causes of aircraft accidents including
the mid-air collision between an All Nippon Airways aircraft and a Japan Air Self-Defense Force fighter
jet flying over Shizukuishi and the crash of a Toa Domestic Airlines aircraft in Hakodate, both of which
occurred in 1971. In 2001, the committee was reorganized into the Aircraft and Railway Accident Investigation Committee, with its investigative responsibility expanded to include railway accidents. This
reorganization was a response to the train accident that occurred in Shigaraki in 1991, the 2000 Hibiya
Line accident, and requests from families of the victims in both accidents. In 2008, the JTSB, which is
responsible for investigating causes of aircraft, railway, and maritime accidents, was created as there wasa need to transfer authority over such investigation from the Marine Accident Inquiry Agency (the present-day Japan Marine Accident Tribunal). Put briefly, this need for transfer of authority arose because
the International Maritime Organization decided to add to the SOLAS Convention a code stipulatingthat investigation of causes of maritime accidents be separated from disciplinary functions.
Whereas the traditional accident investigation committee was an affiliate body of the MLIT (“council (shingi kai)” in Article 8 of the National Government Organization Act), the JTSB is an external body
(gaikyoku) of the MLIT (Article 3 of the Act) and thus has greater independence from the ministry.19)
The JTSB has newly granted authority to give recommendations directly to parties linked to causes ofaccidents (Articles 5 and 27 of the Act for Establishment of the Japan Transport Safety Board), to create
its own rules (Article 16 of the Act), and to make decisions on personnel matters concerning secretariat
staff (Article 55 of the National Public Service Act).19)(2) Accident investigation and criminal sanctions
The process of JTSB’s activities aimed at preventing recurrence of accidents is mainly as follows: investigation of the accident site and physical evidence; interviews with parties linked to the cause of the accident; preparation of an accident investigation report; and recommendations and proposals. Relevant
criminal proceedings by the police or prosecutor often take place simultaneously. It is therefore essential
for them to properly perform their respective roles. For example, if materials collected by the JTSB inthe course of its investigation are used in criminal proceedings, it could make parties linked to causes of
the accident hesitate to provide necessary information.
Before the creation of the JTSB, this issue became apparent in a case of a defendant charged withprofessional negligence resulting in death or injury (Nagoya District Court judgment, July 30, 2004;
Hanrei Jiho, no. 1897, p. 144). A summary of the case is as follows. In 1997, a Japan Airlines MD-11(6)preparing for landing over the Shima Peninsula exceeded its planned descent rate, which triggered theautomatic control system. This became one of the reasons for the subsequent repeated vertical shakingof the aircraft’s nose. Because of the shaking, one flight attendant died, and other flight attendants andpassengers were seriously injured. The captain of the aircraft was later charged with professional(6) According to the judgment, the aircraft’s stability in vertical movements was low because the weight is shifted toward the back of theaircraft as the fuel tank was moved to the back to improve fuel economy and because the horizontal stabilizer was small by design. Dueto this low stability, a computer-controlled pilot system was used.

Chapter 10: Laws and policies pertaining to traffic safety｜113

negligence resulting in death or injury. In the first and second trials, the issue was whether the incident
was caused by the automatic control system or by the captain’s error in controlling the aircraft. The prosecutor used as evidence the accident investigation report prepared and published by the Aircraft Accident Investigation Committee, but the defense argued that the use of the report in the criminal suit violates the Chicago Convention and international standards specified in the Annex to the Convention.
Article 5.12 of Annex 13 of the Chicago Convention states that “[t]he State conducting the investigation of an accident or incident shall not make the following records available for purposes other than
accident or incident investigation, unless the appropriate authority for the administration of justice inthat State determines that their disclosure outweighs the adverse domestic and international impact
such action may have on that or any future investigations” and lists as such records “all statements takenfrom persons by the investigation authorities in the course of their investigation.” (7) Regarding this provision, the judgment provides the following explanation. The Annex is neither the Convention itself nor
a convention that is adopted by consensus of the signatories or that is binding on the signatories. However, the Convention has adopted standards through the Annex in order to realize uniform procedures
and, with the system of notification of differences, has required countries that adopt separate measuresincompatible with standards specified in the Annex to notify their intention. Therefore, it is reasonable
to think that countries not submitting a notification of differences are considered to be showing an
intention to comply with the standards set in the Annex.(8) For this reason, in criminal proceedings thecourt needs to take into account restrictions in Article 5.12 of Annex 13 when it examines evidence.
The judgment interprets Article 5.12 as follows. The tenor of the Article shows that it is a provision
restricting disclosure of records listed in it. Also, even though the purpose of accident investigations by
the Aircraft Accident Investigation Committee is to prevent recurrence of similar accidents, the stipulation that in criminal proceedings for aircraft accidents, even the use of already widely available records
must require consideration of its adverse domestic and international impact on current or future investigations puts an excessive restriction on criminal trials. Therefore, it is reasonable to interpret the Article as restriction on disclosure of records as seen in the tenor of the Article.
Based on these views, the court determined that since the accident investigation report had alreadybeen published, it was not subject to the restriction described in the Article and made a judgment basedon the premise that the report could be used as evidence. More specifically, the court regarded the investigation report as an equivalent to a written expert opinion (kanteisho) specified in Article 321, Paragraph 4 of the Code of Criminal Procedure, accepted the report as evidence, and found the captain not
guilty of negligence.(9)(7) The note to Article 5.12 states the following: “Information contained in the records listed above, which includes information given
voluntarily by persons interviewed during the investigation of an accident or incident, could be utilized inappropriately for subsequentdisciplinary, civil, administrative and criminal proceedings. If such information is distributed, it may, in the future, no longer be openly
disclosed to investigators. Lack of access to such information would impede the investigation process and seriously affect flight safety.”(8) At the time of the trial, Japan had not submitted a notification of differences with regard to Article 5.12.
(9) In passing, the issue of how Article 5.12 would be considered in a domestic criminal trial was not discussed in the second trial (Nagoya High Court, January 9, 2007; Hanrei Taimuzu, no. 1235, no. 136; not guilty verdict).

114｜Theory

The above discussion shows that today’s accident investigations must not only be separated from
criminal sanctions, but also be consistent with international rules. The judgment implies that more critical situations can arise with regard to unpublished investigation reports.
10.5.4 Conclusion: Toward a Society where everyone has access to safe transportation
There are various dangers and risks associated with transportation. In addition to the problems of aging
tunnels and commercial operators’ prolonged driving resulting from deregulation which are discussed
in this chapter, attention is currently being paid to reckless driving caused by dangerous (illegal) drugs.
Efforts for securing safety are being made continuously. It is our hope that careful discussions on thetheory of risk will continue between legal and policy scholars and researchers in other fields in order toenable design and implementation of a legal framework for realizing a society with safer transportation
systems.

References
1) Krüger, Herbert. 1969. Marktwirtschaftliche Ordnung und öffentliche Vorhaltung der Verkehrswege. Darmstadt: Hestra Verlag.
2) Sekine, Kenichi, Shigeru Kitamura, Jun Kurata, Yoshiyuki Tsuji, Toru Ogino, Satoru Shimane, and Hayato Takagi, eds. “Dorokotsu no kanri” [Road traffic maintenance]. In Koza keisatsu hou Vol. 3: 148–525. 2014. Tachibana Shobo. (in Japanese)
3) “Special Supplement: Long Driving Hours and Fatigue.” IATSS Review Vol. 38, No. 1, 2013. (in Japanese)4) “Special Supplement: New Developments in the System of Road Laws–towards the Creation of Human-centered Roads.”
IATSS Review Vol. 35, No. 2, 2010. (in Japanese)5) Saito, Makoto. 2011. “Chiho bunken kaikaku to doro kotsu gyosei” [Decentralization reform and administrative road traffic]. IATSS Review Vol. 35, No. 3: 233–238. (in Japanese)6) Shiroyama, Hideaki. 2010. “Tekunoroji asesumento no tembo to kadai” [An overview of technological assessment and its
issues]. Jurist No. 1409: 2–6. (in Japanese)7) Oshima, Keitaro. 2006. “Unyu anzen ni kakaru aratana sukimu no jitsugen: unyu anzen manejimento hyoka no jisshi ni
mukete” [Realization of a new scheme for transportation safety: assessment of transportation safety management]. Transport
Policy Studies’ Review Vol. 9, No. 2: 62–65. (in Japanese)8) Misaki, Shigeki, Hideaki Shiroyama, and Hisakazu Hirose. 2003. “The preventative role of indemnity insurance in promoting public safety: The preliminary analysis of its function.” Sociotechnology research Network Vol. 1: 198–207. (in Japanese)9) Shiroyama, Hideaki. 2004. “Legal System for Safety: Sanctions and learning, role of third parties and international harmonization.” Shiso Vol. 7, No. 963: 140–163. (in Japanese)10) Imai, Takeyoshi. 2007. “Inshu unten taisaku rippo no igi to kadai” [Purpose and issues of legislating countermeasures against
drunken driving]. Jurist Vol. 1342: 128–134. (in Japanese)
11) Imai, Takeyoshi. 2007. “Inshu unten taisaku toshite no bassoku no seibi” [Development of penalties for drunken driving as acountermeasure]. Jurist Vol. 1330: 24–31. (in Japanese)
12) Imai, Takeyoshi. 2005. “Kotsu jihan to sono keijihoteki kisei: kinji no jokyo o fumaete” [Traffic-related crimes and the regulation from the perspective of criminal law: based on the recent situations]. IATSS Review Vol. 30, No. 4: 465–469. (inJapanese)
13) Imai, Takeyoshi. 2014. “Kiken unten chishi shozai o meguru mondai jokyo” [Issues regarding the crime of dangerous driving
resulting in death or injury]. In Kotsu jiko to sekinin noryoku [Traffic accidents and responsibility capacity], edited by Japan
Association of Traffic Law, Kotsuhokenkyu Vol. 42: 129–175. (in Japanese)
14) Imai, Takeyoshi. 2008. “Kotsu jihan no houkisei o meguru gendaiteki kadai” [Today’s issues regarding the regulation of traffic-related crimes]. Crime and Delinquency No. 157: 88–103. (in Japanese)15) Yoshida, Tadao, ed. 1982. Kagaku yakuhin no anzen [Safety of chemical products]. Taisei-shuppan. 4–5. (in Japanese)16) Yoshida, Tadao, ed. 1988. Hannosei kagaku busshitsu to kakohin no anzen [Safety of reactive chemical substances and explosive devices]. Taisei-shuppan. 31–32. (in Japanese)Chapter 10: Laws and policies pertaining to traffic safety｜11517) Hasebe, Yasuo, ed. 2007. Risuku gaku nyumon 3: horitsu kara mita risuku [Introductory risk studies 3: risk from the perspective of law]. Iwanami Shoten. (in Japanese)18) Shiroyama, Hideaki, and Yoichi Nishikawa, eds. 2007. Hou no saikochiku III: kagakugijutsu no hatten to hou [Reconstructionof law III: Development of science and technology, and law]. University of Tokyo Press. (in Japanese)
19) Uga, Katsuya. 2010. “Unyu anzen iinkai no genjo to kadai.” [Current condition of Transport Safety Board and its issues].
Jurist No. 1399: 10-20. (in Japanese)
Recommended Reading
1) Noguchi, Kikumi. 2009. “Norimono no anzen anshin” [Safety and security of vehicles]. In Anzen, anshin no gyosei hougaku[Safe and secure administrative jurisprudence], edited by Noguchi, Kikumi, and Masaharu Koda. Gyosei. (in Japanese)
2) Sekine, Kenichi, Shigeru Kitamura, Jun Kurata, Yoshiyuki Tsuji, Toru Ogino, Satoru Shimane, and Hayato Takagi, eds. 2014.
“Doro kotsu no kanri” [Road traffic maintenance]. In Koza keisatsu hou Vol. 3: 148–525. Tachibana Shobo. (in Japanese)
3) Beck, Ulrich. 1986. Risikogesellschaft. Frankfurt am Main: Suhrkamp Verlag.
4) Calabresi, Guido. 1985. Ideals, Beliefs, Attitudes, and the Law. New York: Syracuse University Press.
5) Hasebe, Yasuo, ed. 2007. Risuku gaku nyumon 3: horitsu kara mita risuku [Introductory risk studies 3: risk from the perspective of law]. Iwanami Shoten. (in Japanese)6) Shiroyama, Hideaki, and Yoichi Nishikawa, eds. 2007. Hou no saikochiku III: kagakugijutsu no hatten to hou [Reconstructionof law III: Development of science and technology, and law]. University of Tokyo Press. (in Japanese)
Practical application projects for reference
Creating installation guidelines for tactile ground surface indicators (braille blocks) for the visually impaired: 184–187
Ensuring urban public transportation mobility for people with intellectual disabilities: 188–191
A study on the level of service for local public transport to secure basic daily life: 192–195
Traffic safety and traffic enforcement: 196–199
Interdisciplinary research on the criminal charge of dangerous driving causing death or serious injury: 200–203
Smoothly promoting urban development for transportation through collaboration between government and local organizations:
204–207

Chapter

11

Sustainable growth—
An economic perspective
11.1

Cost-benefit analysis

11.1.1 The purposes and theoretical foundation of cost-benefit analysis
Cost-benefit analysis (CBA) is applied to evaluate the economic effect of transportation facilities such as
roads and railways and to support decisions regarding whether to take on projects.1) A federal waterway
project by the Tennessee Valley Authority, which was begun during the 1930s as part of the New Deal in
the United States, was the first systematic evaluation using CBA. The purpose is to determine whether asufficient development effect would be realized when investing the large amounts of money required toconstruct dams and other massive projects.
CBA is applied not only to transportation facilities but to a wide range of evaluations for public
investment. The basic idea is to calculate and compare in terms of monetary units the costs required fora project and the benefits derived from it. In the case of transportation facilities, monetary costs include
those required for development (construction), ongoing maintenance, and other costs paid by public
entities. There are also cases where negative effects to society resulting from the project, such as worsening of the environment, are included in the calculation as additional costs or negative benefits.
The main benefits from transportation facilities include benefits from timesaving, benefits fromreduced movement costs (in the case of road development, fuel savings), benefits from improved safety,
and benefits from improved comfort. Due to the nature of transportation facility development, benefits
due to time savings account for a majority of the overall benefits. Several evaluation methods have beendeveloped for costs and benefits such as time, safety (reduced accident risk), and comfort.
11.1.2 Evaluation criteria in CBA
Because of limitation of project budgets (financial resources), CBA is applied not to determine whether
projects should be carried out, but rather to make a relative comparison for selecting between alternatives. There are three main criteria for project evaluation:

Chapter 11: Sustainable growth—An economic perspective｜117(1) Net present value method
Net present value is given by the following equation:
T

T
Bt
Ct
−
−K
∑
t
t
t =0 (1 + i )t =0 (1 + i )NPV = B − C − K = ∑Here, NPV is the net present value, B is the present value of total benefits in base year 0, C is thepresent value of total maintenance costs in base year 0, K is the present value of construction costs inbase year 0, t is the year, T is the evaluation term (durability in years), Bt is the benefits in year t, Ct is themaintenance costs in year t, and i is the social discount rate. In this evaluation method, the larger the
NPV, the better the project.
(2) Benefit-cost ratio method
In this method, the larger the benefit-cost ratio, the better project. Benefit-cost ratio is defined as theratio of the benefits of a project relative to its costs. In practice, two ratios can be used: (B–C)/K, whichis the net benefits per unit of investment (construction costs); and B/(C+K), which is the ratio of grossbenefits to total costs. As both ratios represent cost-benefit ratios, it is necessary to choose in advancewhich ratio is used for the project appraisal.
(3) Internal rate of return method
Internal rate of return represents how much the rate of return from an investment increases, and thelarger the internal rate of return, the better the project. The internal rate of return r is calculated by solving the following equation:
T

Bt∑ (1 + r )
t =0

T

−∑
t
t =0

Ct

(1 + r )t=K

Internal rate of return is the criterion most consistent with economic theory. However, in cases
where huge costs occur at the end of the evaluation period, such as when nuclear power plants aredecommissioned, r can sometimes represent multiple possible solutions. Note that this rarely occurs intransportation improvement projects, so this method is recommended for the project evaluation.
11.1.3 Foreign exchange rate issues
In cases where funds are procured domestically, the evaluation methods described above can be applied
regardless of whether funding will be through taxes or bonds. In cases where funding occurs throughinternational investment, however, variation in future foreign exchange rates must be taken into account.
In developing countries in particular, it is important that project evaluations consider the ability of thenation to repay foreign debt.2), 3)

118｜Theory

11.2

Balanced and unbalanced growth

11.2.1 Theories of balanced and unbalanced growth(1) Nurkse’s balanced growth theory
The scale of a country’s economy is determined by its trading conditions with other countries, in addition to other factors including the three major factors of production (land, private capital, and labor), as
well as the country’s saving rate, inflation rate, social overhead capital, and technology level. There isthus a wide variety of aspects for analysis in economic growth theory, one of which is research regarding
economic growth paths.
Nurkse’s balanced growth theory4) is one perspective regarding the path that a country takes during
economic growth. Nurkse gave a lack of private investment as one cause related to the failure of developing countries to realize economic growth, and proposed balanced growth as a way of inducing private
investment, on the assumption that balanced increases of production would expand markets. This theory is not well supported in recent years.
(2) Hirschman’s unbalanced growth theory
Another approach is Hirschman’s unbalanced growth theory.5) There are various difficult-to-solve problems that impede economic growth in developing countries, and such countries do not possess sufficient
resources or capital to simultaneously solve them all. Accordingly, to pursue rapid economic development, the best strategy is to focus investment of resources and capital on strategic growth industries, andto maintain such a disequilibrium. Such strategic industrial growth would later have positive repercussions for other industries and contribute to nationwide economic growth.
11.2.2 Social overhead capital and private capital
Unbalanced growth theory can be
Private capital
applied to the balance between
Unbalanced growth path emphasizing private capitalsocial overhead capital (public
Binvestment) and private capital(private investment). Figure 1

shows the path of each growthstrategy, with A as a departure

Balanced growth pathpoint and B as a destination. Three
examples of growth paths between
points A and B are shown. The
horizontal axis indicates stock levels of social overhead capital, andthe vertical axis indicates stocklevels of private capital. In eachcase higher stock levels indicate

0A

Unbalanced growth path emphasizing
social overhead capitalSocial overhead capital

Figure 1. Balanced and unbalanced growth paths

Chapter 11: Sustainable growth—An economic perspective｜119higher potential productivity and thus higher potential economic growth.
In Fig. 1, the dotted line at a 45° angle is the path of balanced growth. In other words, investment
occurs in a balanced manner such that marginal productivity is equalized between private and social
overhead capital. In contrast, the curve at the top is a growth path in which private capital takes precedence over social overhead capital, and the curve at the bottom conversely prioritizes social overhead
capital development. The issue at hand is the speed and cost required to move from A to B. Unbalanced
growth theory states that an unbalanced growth path arrives at B more quickly and at a lower cost (specifically, a lower opportunity cost of capital) than the balanced path does.
Yet when considering whether to prioritize private or social overhead capital, it is insufficient toconsider only the opportunity cost of capital. This is because while decision makers behind privatesector investment are private individuals, social overhead capital investment is exclusively a public entity.
This is particularly true in the case of transportation facility development, where even within the same
country the emphasis on private or social overhead capital will vary from region to region.
In cases where economic growth is so high that social overhead capital development cannot keep
up, an unbalanced growth route that emphasizes private capital will be taken. From the viewpoint oftransportation facility development, this is a case of transportation social overhead capital development
aimed at keeping up with emerging demand. In other regions where private economic activities are stagnant, the government often may undertake transportation facility development for regional vitalization,
which means that the government takes an unbalanced growth path that emphasizes social overhead
capital. This is an example of transportation social overhead capital development that precedes economic development. In this case, failure to attain a sufficient regional development effect would result in
failure to reach point B and the development of transportation facilities could be considered wasteful.
11.2.3 Forward and backward linkage effects
There are two types of economic effects resulting from public investment in transportation facilities: forward linkage effects and backward linkage effects.
Forward linkage effects are benefits (economic effects) from public services provided by the facilities developed through public investment. In other words, these are effects in which public investment
results in increased social overhead capital stock, thus increasing potential productivity. The forward
linkage effects of a project are recorded as benefits of the project in CBA.
Backward linkage effects are the economic effects of increased demand for a resource that is devoted to
public investment, in particular economic effects in the regional economy. In other words, public investment activity results in increased demand for materials and labor, thus increasing income to material
and labor suppliers. Backward linkage effects are often emphasized as being important economic effectsof public investment programs for regional economies.

120｜Theory

11.3

Economic policy against traffic congestion6)

11.3.1 What is congestion?
Congestion is the result of a concentration of relatively large demand in comparison to the capacity offacilities or equipment, and causes many monetary and nonmonetary costs that do not arise in cases ofno congestion. In the transportation area, these include problems such as crowding on trains and congestion on road networks. In any case, it is assumed that supply levels cannot be changed in the shortterm and that collective consumption is possible up to a certain level. Exceeding that level results inexternal diseconomies, indicating conditions that hinder the intended use. In this paper, we mainly deal
with road congestion problems that many cities in the world suffer.
11.3.2 Economic understanding of congestion
Roads are a resource for which collective consumption is possible up to a certain level, allowing users todrive smoothly. However, when a road becomes congested, the driving speed on the road decreases,
increasing costs such as time and fuel costs required to reach a destination.
Figure 2 shows such an example, with traffic flow on the horizontal axis and required costs on
the vertical axis. Road capacity F0 is
the upper limit on possible equal
consumption, and when automobiles in excess of this limit enter
into the road, marginal costs begin
to increase. In other words, theinflow of additional traffic resultsin decreased driving speed andCMarginal social cost curve
C
Marginal private cost curve
B

D

ｔ

A

E
Demand curve

0

F0

F*

F’

F

Figure 2. Occurrence of congestion

increased time requirements foreach driver, increasing marginal private costs. All drivers experience this increased cost resulting fromthe inflow of additional traffic in a similar way, so the marginal social cost curve diverges.
Following the concept of a Pigovian tax from microeconomics, this external diseconomy can beinternalized by imposing a tax rate t, allowing attainment of an optimal congestion level F*.
11.3.3 Example of introduction of a congestion charge
Road congestion is a significant problem in many cities throughout the world. Although the aims arevarious, many cities such as Singapore, Oslo, and London have introduced congestion charging to downtown areas. London was the first city in an industrialized nation to attempt this, with a scheme designed
to reduce inner-city traffic.
Beginning with the 1964 Smeed Report, there have been many studies and discussions on introducing a road congestion charge in London, but establishment of the Greater London Authority in 1997

Chapter 11: Sustainable growth—An economic perspective｜121

and the 2000 election of a mayor who supported theidea laid the groundwork for actual implementation.
In 2003, the London Congestion Charging Scheme
was introduced for improving traffic flow. Under
this scheme, automobiles entering areas designatedby Transport for London between 7:00 and 18:00 on
weekdays were subject to a charge of £5 per day. The
charge was incrementally raised, and as July 2014
stands at £11.5 per day. Signs such as the one shownin Fig. 3 are posted at entrances to the congestion

Figure 3. Entrance sign in London indicating thecongestion charge zone(1)charge zone, and cameras record vehicle license
plates to create records of who should be charged. All the money collected as a road congestion charge isdesignated for use toward developing and maintaining public transportation.7)
According to a published fact sheet, the congestion charging scheme has resulted in a 27% reduction in the number of vehicles in the congestion charge zone, as compared to 2002 figures before theintroduction of the scheme. Bicycle usage has increased by 66%, indicating a shift away from the use of
automobiles.

11.4

Economic policy and environmental problems6)

11.4.1 Transportation and environmental problems facing modern society
There are many environmental problems caused by transportation, including air pollution, global warming, noise pollution, and vibration. In particular, many countries are working hard to develop measures
for reducing atmospheric pollutants and greenhouse gas emissions. All modes of transportation increase
environmental load to some extent, but on a per-emissions-unit basis automobiles are particularly
problematic.
Atmospheric pollutants have a direct negative effect on human health, and materials such as nitricoxides, sulfur oxides, and particulate matter are generated in areas with many automobiles. Global
warming is a result of the production of large quantities of greenhouse gases, with carbon dioxide considered to be a particularly large contributor. Carbon dioxide itself does not have a direct effect onhuman health, but it is believed that we are producing it in such large quantities that we are increasing
the temperature of the Earth’s surface, which in the future will lead to large effects such as rising sea levels and changes in vegetation.
11.4.2 Understanding environmental problems from an economic perspective
In economics, environmental problems are treated as the results of external diseconomies that lead to(1) From the Transport for London website

122｜Theory

overuse of a given service. Such overusecreates deadweight loss, so social surplus

C
Marginal social cost curve

is not maximized.
As Fig. 4 shows, a Pigovian tax caninternalize this external diseconomy byimposing a tax rate t that attains an opti-

Marginal private cost curve

mal level F*.

t
Demand curve

11.4.3 Measures for addressing
environmental problems

0

F*

F’

F

As discussed in the section above, enviFigure 4. Environmental diseconomies and Pigovian taxationronmental problems are caused by excess
gaseous and particulate emissions. Measures that can be considered for reducing such emissions fromautomobiles can be categorized as those that (1) improve automobile performance, (2) suppress automobile usage, and (3) promote efficient automobile usage. Respective examples of such measures are (1)lowering the discharge rate of pollutants an automobile releases, (2) suppressing automobile usage
through a switch to public transportation, and (3) reducing the number of vehicles used through more
efficient utilization of automobile space.
A number of policy techniques can be applied to realizing such measures, but economic methods
that utilize market mechanisms can allow for smoothly achieving these goals.
In the case of (1), reducing the acquisition and holding taxes associated with environmentallysound vehicles are effective; consumers would be more likely to select economically sound vehicles thatcarry a lower tax burden, thereby pushing automobile manufacturers to develop more of such vehicles
and improving the average fuel consumption of new vehicles and improving the average performance ofvehicles on the road. In the cases of (2) and (3), as described in Section 11.4.2, additionally imposing
fuel taxes can promote higher efficiency at the usage level.
11.4.4 Economic
instruments targetingthe automobile
environment in Japan
In Japan, a policy called the“greening of automobile-related
taxes” has been implemented
since 2001 with the goal of
improving the environment

Thousands of vehicles

3,500

km/L

3,000

20

2,500

18

2,000
1,500

Average fuel consumption (km/L)

16
14

1,000
500

22

Number of hybrid, natural gas,and electric vehicles

through increased automotive
performance. This policy lowers

0

acquisition and holding taxes for

Figure 5. Performance improvement trends for automobiles in Japan

12
10

Chapter 11: Sustainable growth—An economic perspective｜123

exceptionally environmentally friendly vehicles, while increasing taxes for vehicles with poor environmental performance.
This has resulted in consumers selecting more low-emission vehicles with lower taxes and in manufacturers making efforts to improve environmental performance of vehicles, thereby increasing ownership rates of hybrid, electric, and natural gas vehicles and improving overall per-liter fuel efficiency (Fig.
5). Such efforts have resulted in a trend of reduced carbon dioxide emissions from the transportation
sector in Japan.

11.5

Economic regulations and deregulation

11.5.1 Regulations on transportation services
Transportation operations are generally considered susceptible to public intervention. Regulations canbe roughly divided into “social regulations” and “economic regulations,” with social regulations being
qualitative regulations related to safety and the environment, and economic regulations being quantitative regulations related to effects on market supply and demand. Economic regulations are further categorized as price regulations and entry regulations. The supply and demand of transportation industries
in particular have been adjusted, with public competition inhibited. In recent years, however, there has
been a worldwide movement toward deregulation, with the goal of improved efficiency through competition in transportation markets.
11.5.2 Necessities and limits of regulation
One might ask why transportation markets in particular have long been subjected to economic regulation. One reason is that economies of scale in a given market are believed to lead to natural monopolies.
Economies of scale often occur in industries with large fixed costs, and when companies freely compete,
they bring down the prices, compete on service quality, and create “destructive competition.” When
competitors leave the marketplace and a natural monopoly has arisen, the victor is free to enjoy monopoly benefits and consumers will then be faced with monopoly prices. Furthermore the investments madeby competitors that leave the market become “sunk costs” that cannot be recovered, representing a social
loss.
Transportation markets have many of these features, and the high demand for transportation services would result in large effects, so long-lasting monopolies and oligopolies have been accepted in
exchange for their being the subject of price regulations. Note that price regulations have been applied
under the “full cost principle,” which holds that necessary revenue equates to costs occurring under efficient management plus a fair profit.
However, the full cost principle does not provide operator incentives for cost reduction, and has led
to inefficient management and further increased pricing. According to the theory of contestable markets
presented by Baumol and others since the mid-1970s, this led to changes in public intervention in thetransportation industry.8)

124｜Theory

11.5.3 Contestable market theory
A contestable market is one with free entry and with no cost associated with leaving the market, allowing hit-and-run strategies. When a market is completely contestable, existing companies act efficiently,
for reasons described below.
In the case where an existing company has a monopolistic or oligopolistic market and thus enjoys
excessive profits, new companies can enter the market offering a lower price, thereby capturing all thecustomers and making a profit. In response to this, an existing company offer equivalent or lower prices,
the new company will lose their profits, forcing them out of the market. By the same theory, even in thecase where an existing company has a monopolistic market, one in which entry and exit by new companies does not entail sunk cost, the threat of new participation promotes the setting of efficient prices.
11.5.4 Expansion of deregulation
Taking contestable market theory as a theoretical background, in 1978 the United States deregulated
domestic airline services, and after that, transportation segment deregulation spread around the world.
Examples include bus and airline industries in the United Kingdom, as well as the airline, taxi, andtrucking industries in Japan.
In the mid-1990s, the Japanese airline industry moved from being non-competitive to being competitive, and ease of market entry and pricing deregulation were promoted. The result was an influx of
new operations in the industry, including even new operations by existing airline companies, accompanied by diversification of pricing and services. The Japanese airline industry is still not yet a true contestable market, however, due to congestion at airports such as Tokyo’s Haneda Airport preventing free market entry. In such cases, the role of public entities is still large in regard to issues such as dividing new
airport slots among airline companies.
References
1) Mishan, E. J., and E. Quah. 2007. Cost-Benefit Analysis. 5th edition. Routledge.
2) Brent, R. J. 1998. Cost-Benefit Analysis for Developing Countries. Edward Elgar.
3) Dinwiddy, C. L., and F. J. Teal. 1996. Principles of Cost-Benefit Analysis for Developing Countries. Cambridge University Press.
4) Nurkse, R. 1961. Patterns of Trade and Development, mimeo, 1959. Blackwell.
5) Hirschman, A. O. 1958. The Strategy of Economic Development. Yale University Press.
6) Bamford, C. G. 2006. Transport Economics. Heinemann.
7) Transport for London. 2014. “Transport for London Congestion Charge Factsheet.” Transport for London. Accessed September 25, 2014. https://www.tfl.gov.uk/cdn/static/cms/documents/congestion-charge-factsheet.pdf.
8) Baumol, W. J. 1982. “Contestable Markets: An Uprising in the Theory of Industry Structure.” American Economic Review vol.
72, No. 1.
Recommended Reading
1) Boardman, A., D. Greenberg, A. Vining, and D. Weimer. 2013. Cost-Benefit Analysis: Concepts and Practice. 4th edition.
Pearson.
2) Vickers, J. and G. Yarrow. 1995. Privatization. MIT Press.

A student waiting at 4:30 a.m. for abus in a suburb of Bangkok to go toschool located in the city center1)

Final thoughts

Resilient mobility
society
Before concluding the Theory section, this chapter will explain “traffic resilience” as a concept essential
for transportation during ordinary times as well as during emergencies. Here, three important levels intransportation will be kept in mind: technology, systems, and society.
Besides denoting the ability to recover or stabilize, “resilience” also means flexibility. To define resilience in terms of moving people or objects, a resilient object would be one on a tightrope that, whenever
it is shaken or pushed to the side, will always come back to its original standing position. In tightropewalking, balance can be restored against a certain amount of swaying if there is something like a balancing pole to act as a stabilizer. If the tightrope walker stops, however, the balance maintained while walking may be lost and the rope may start swaying. Sustainability, which is used in contrast to resilience, isconceptualized as the ability to use one’s last step as support in taking one’s next step forward, without
stopping. The basis for sustainability, the ability to take that step forward, could not be formed without
resilience—the stability of ground to stand on Fig. 1. In this sense, instead of defining resilience as aSud
soc dencha ioecon
nge om
ic
Ma
jor d
isas
ters
Unf
acc oresee
iden nts

Stabilization
deviceResilience
The ability to recover
flexibly from external
forces and impacts

Sustainability
Making forward progress
while keeping balance

Figure 1. Resilience and sustainability

126｜Theory

special quality for times of disaster or emergency, resilience should be defined as a prerequisite for accumulating steps forward each day, and realizing a safe and sustainable mobility society.
Below, I introduce the connotations of resilience learned through my own experiences in a developing country in Asia. Factors involved in realizing a resilient mobility society are also discussed.

Non-resilient traffic situations
I visited Bangkok and stayed with a friend of mine in the 1990s. During my visit, there was an incident
where the school bus my friend’s children rode had not arrived by 8:00 p.m., even though it usually
arrived by 5:00 p.m. We were all worried that the bus had been involved in some sort of accident, but itturned out it was just stuck in traffic.
In those days, I was involved in the Advisory Committee of JICA for the Study on Improvement
Plan for Railway Transport in and around the Bangkok Metropolis in consideration of Urban Development in the Kingdom of Thailand (1992–96), which was organized by the Japan International
Cooperation Agency in order to alleviate the huge traffic jams in the city of Bangkok by using the railway system as a cornerstone. Having been appointed as the chair of the project, I was astonished that thecity’s traffic congestion was extraordinary. A survey conducted at the time revealed that the percentageof people who spent more than 8 h a day commuting in the Bangkok Metropolitan Area had reached10%. Although I did not know the term “resilience” at that time, when I learned the word, I came torealize that the traffic congestion in Bangkok had been totally non-resilient.
A group of Japanese and British researchers attempted to remedy the congestion in Bangkok using
traffic signals, but soon ran out of options because of the reality of the situation, where the tail end ofvehicle queues at one traffic signal would enter through the intersection at the next traffic signal. Oncevehicles entered an intersection for a right or left turn, they could no longer move and stayed at an
oblique angle to other traffic lanes. This is gridlock, meaning the paralysis of the grid-like system ofroads. A traffic jam with no moving vehicles spreads through the entire network of intersecting streets.
As soon as a traffic jam started at one intersection, vehicles at the next intersection also came to a stop,and this spatial propagation affected other intersections one by one. From the perspective of the system,a microsociological phenomenon at individual intersections transforms into the macrosociological phenomenon of hypercongestion. The phenomenon then propagates throughout the entire road networkand paralyzes it. This is similar to dysfunction in one area of the body spreading throughout the bodyand incapacitating the entire regulatory network.
In terms of time, hypercongestion is characterized by an increase in travel time and in the size of its
fluctuations because, for example, a certain distance that required 2 h to travel yesterday may require 4 h
today. When considering traffic resilience, it can be said that traffic is resilient if travel time fluctuations
converge within a certain range. However, when fluctuations extend outside of this range and cause thetraffic to become divergent and lose the ability to recover, this can be regarded as non-resilient traffic.
Non-resilient traffic becomes extremely unstable, making prediction of travel times impossible, andFinal thoughts: Resilient mobility society｜127

affects not only the transportation system, but also urban activities and the economy. For example, it
may become impractical to make multiple business appointments for the day, and only one meeting may
be scheduled for the morning or afternoon. I witnessed how the resilience of society was lost because of
the adverse effects of traffic congestion.

Establishment of a multidisciplinary organization to address problems
Around 1992, the State Railway of Thailand (SRT) was in a very weak position. In developing countries
including Thailand, the railway system was considered to be a dirty transportation system used by only
people at the bottom of the social strata. Because of daily delays, railway systems were not trusted andmost government officials involved in decision-making used chauffeur-driven cars and had no interestin railways. Consequently, even when the significance of railway systems was explained at the National
Railway, which should be the center of the railway system, the idea could not reach the decision-making
officials.
The project we undertook aimed to revive the railway system within 200 km of Bangkok. However,
we could not access or use the land under the railways in the central part of the SRT network, which
included 15 km of the Northern Line and 30 km of the Eastern Line, because the land use rights were
held by the Hopewell real estate company, based in Hong Kong. Because of this, we decided to embark
on the following two things. First, to move the project forward, we established a multidisciplinary organization. Instead of attempting to proceed through only the SRT, we made the steering committee aninterdisciplinary body spanning various government ministries, and asked Administrative Vice Minister
Sansern of the National Economic and Social Development Board of Thailand (NESDB) to serve as thecommittee chair and Vice President of the National Railway to serve as the vice committee chair. We
also requested the participation of officials involved in land utilization or transportation, such as thosein the Housing Agency and the Ministry of Transportation.
The NESDB was an organization similar to the then Economic Planning Agency of Japan, yet had
authority equivalent to that of the Department of the Interior. We comprehensively explained to thecommittee members how significant the railway system was. At that time, Bangkok already had a population of 6 million and the entire Bangkok Metropolitan Area had a population of 11 million. Bangkok
was a megacity that needed to use the railway system to resolve the basic issue of transportation demand.
We tried to make the committee members understand that if only roads, but no railways, were used toaddress the problem, the transportation demand would not be controlled unless the majority of the metropolitan area was transformed into roads. Amid these efforts, the Bangkok Post reported the concernof King Bhumibol regarding the massive traffic congestion in Bangkok, and this generated a muchneeded tailwind and changed the minds of the committee members.
In a series of related events, the Office of Commission for the Management of Land Transport(OCMLT) was held in 1993. Although traffic-related issues were originally under the jurisdiction of the
Ministry of Transportation, they were placed under the jurisdiction of the Prime Minister to make all128｜Theory

government ministries responsible for addressing traffic-related issues. Under the new system, an interdisciplinary organization was developed, for which Professor Kumropluk, of Urban Planning at Kasetsart University, became the appointed deputy director. In this way, the organization was entrusted toprofessionals in urban planning who had a holistic view of the entire city, which became advantageous
later on.
Another key to solving the traffic congestion was taking the time to continuously and persistently
make all the committee members understand the usefulness of rail transit systems through the whole
period of the JICA’s study. In 1999, 3 years after the final report meeting for the project in January 1996,
the first Skytrain line commenced operation. The development of intercity train tracks had been a longsought plan of Governor Chamlong and Deputy Governor Winai since the 1990s. We made some materials to illustrate to the passengers of the elevated line that they would be able to look down at the traffic
congestion below before returning home between 6–7 p.m. and enjoying dinner with their families. At
the time, such a lifestyle was absolutely impossible, as it took 4 h to go home after work. However, we
continued to show such a lifestyle as the future lifestyle of Bangkok and continued to draw attention.
Finally, the road to realization was opened when elevation of the Skytrain rails was completed.

Innovative attempts to create novel travel styles, habits, and culture
To increase the acceptance of new transportation technologies and systems, it is important to persuadepeople exhaustively as well as allow them to actually experience the new transportation technology sothey may go on to talk about it. One of my friends, an assistant to the president of Chulalongkorn University, gave great praise to the reduction in her commute time from 1–2 h one way by car to 15 min by
Skytrain.
One of the factors that contributed to the creation of the novel style of travel on Skytrain was theflat fare of 30 baht. There was a debate over whether the fare should be 20 or 30 baht. Some raised a concern that the fare of 30 baht would deter low-income people from taking Skytrains, but ultimately thefare was set at this level. As a result, white-collar workers became the main users, showing that we wereable to attract middle-income people, who would have otherwise bought a car, to commute via the clean
and comfortable railway system. Furthermore, the social status of the users helped to raise the positionof railways in the society. The development of the Skytrain system was followed by the development ofsubways and the Airport Rail Link (maximum velocity, 160 km/h) to Suvarnabhumi Airport, resulting
in a total of 84 km of new urban railways in the 13-year period from 1999 to 2012.
Around the same time as the shift in transportation mode brought about by these measures, theconstruction of urban highways began parallel to the railways. Although the average speed on the streetsin Bangkok was approximately 20 km/h in the mid-1980s, it was reduced to 6 km/h, the same as walking
speed, in 1992. Today, the speed is back to near 16–17 km/h. Last year while speaking with the vicepresident of the public enterprise for the Thai underground subway system, I was pleasantly surprised tohear “two whole hours”, as in, “it took two whole hours to get home from Suvarnabhumi Airport!” AFinal thoughts: Resilient mobility society｜129

travel time that had once been an inconceivably short had come to be seen as unacceptably long.
Three factors played a role in improving the speed on the streets of Bangkok. The first factor was,needless to say, the urban railway systems, including Skytrain, along with the measures such as the faresystem for keeping the infrastructure clean. The second factor was the simultaneous development of theurban highway system. The third was the construction of the outer beltway. The urban highway and railway systems absorbed traffic from the roads, and at the same time, the beltway absorbed the throughtraffic.
In hindsight, traffic resilience was improved by the improvement of systems. At that time, foreign
capital was flowing out of Bangkok into Kuala Lumpur, Jakarta, and Singapore due to the fear of nonproductivity caused by the hypercongestion. However, due to the improvement of the congestion, foreign capital has started to return to Bangkok. In addition, by enhancing the resilience of the transportation system, the economy recovered as well. The return of industry has increased the size of the overall
economic pie, which has gradually increased the distribution of income and thus mean income.
The relationship between transportation systems and society should not be oversimplified.
Although questions remain as to how thoroughly the governments of Thailand and the Bangkok Metropolitan Area considered the effects of this plan, the goal was realized only because of the development of
the interdisciplinary organization that enabled more fruitful discussions.
Following the development of the Skytrain system in 1999, the subway system and the Airport Rail
Link were established one after another. It was fortunate that Professor Kumropluk, who was integral tothe project’s success, became the deputy director of the interdisciplinary organization, and it was also
greatly helpful that the other personnel we supported were able to become the organization’s think-tank
and change the minds of others from the inside.

Resilience and sustainability of the mobility society
Resilience at each time point determines the sustainability of the steps to be made over time. Comparedwith resilience, which is a stage in short-time flows, sustainability is close to the concept of a long-term
stock and is defined as sustained dynamic stability over a long cycle of 20–30 years. This is not to saythat one of them is more important than the other; both are equally essential.
For example, automobile companies are the major players in transportation technology and theiremployees know automobiles very well, but often the companies do not comprehend the overall traffic
situation. This is fatal. It is important to have the proper attitude when considering which frame should
be used to understand traffic-related issues and what common ground is used for this understanding. In
this chapter, mobility society has been examined on three levels: transportation technology, systems, andsociety. However, the key point is the kind of common mindset that the people who develop techniquesand methods use to view the mobility society. It is not simply about social responsibility; breadth isneeded to cross-sectionally share knowledge and awareness. I believe that the founder of the IATSS, Mr.
Soichiro Honda, had keen intuition about transportation-related issues, including how to maintain130｜Theory

resilience and sustainability for the entire mobility society. The IATSS reflects the spirit of its founder
and is of great significance as it continues on as an organization entrusted with these great
responsibilities.
Reference
1) Bangkok Post, September 4, 1993.
Practical application projects for reference
Realization of earthquake disaster crisis management and a society with safe and secure transportation: 208–211

132｜Practice

A land utilization framework and transportation
system for declining population
1. Background and goals
We investigate the question of whether future generations will be able to inherit Japan’s current urban
landscape.
Most of Japan’s current urban landscape was created in the latter half of the twentieth century andparticularly rapid and substantive improvements were made to public-sector social capital such as rivers, roads, ports, airports, and railways. In the latter half of the 1980s, these improvements began to bemade with apparent consideration if they are inheritable into the future under the concept of civic
design.
In contrast, when we turn our eyes to built-up landscape, it has become a common sense that private sector buildings assumed to be replaced in every generation. Japanese housings, even including
those made from concrete, have an average lifespan of only around 30 years. This indicates that they are
regarded as consumable-durable goods to be demolished and rebuilt three times per century. Moreover,almost all buildings are designed in isolation, with no consideration of harmony with their surroundings. As a result, the visual appearance of individual street blocks—which are the units at which collaborative landscape creation can be realized—tends to be somewhat unimpressive and even shabby. Most
cities, therefore, have not been successful in creating urban stock to be inherited to the future
generation.
Another shortcoming is that greenery has not been emphasized in urban areas. Low-rise detachedbuildings have been allowed even near city centers to result in crowded downtown areas with little green
open spaces. Major transportation facilities divide spacious green areas, and low-density built-up areas
spread out to the suburbs. Particularly since the 1970s when increased incomes allowed the average
household to purchase automobiles, urban areas have encroached beyond the reach of railways and further reduced green areas.
Japan currently faces issues of economic maturity and recession accompanying population decline
and aging. This project focuses on whether such unregulated land use are acting to significantly degrade
quality of life in Japanese cities.
In search of hints as to which direction Japan should proceed in the future, we introduce some of
the results of our on-site investigations regarding cooperative land use and transportation systems in

Project Leader: Yoshitsugu Hayashi
Professor and Director, Education and Research Center for Sustainable Co-Development, Graduate School of Environmental Studies,
Nagoya University

A land utilization framework and transportation system for declining population｜133

Western cities where economic development has preceded one step ahead of Japan’s. As a domestic
model, we also introduce the corridor-type land-use system being introduced in Utsunomiya City as anaccompaniment to its light rail transit system. The outcomes of this project have been published in a
book.(1)

2. Research content
2-1. Compact, urban, green (Munich, Germany)
To achieve sustainable economic, social, spatial, andregional development while protecting the environment
and minimizing resource consumption, Munich has
been advocating strategies of compactness, urbanity(fusion of diversity), and greenness (greenery and global
environment) for urban area formation.
Munich has established policies limiting new development to the areas within walking distance of train stations, gradually leading to the realization of compact
urban districts. This has resulted in a concentration oflarge-scale development along railways on the west sideof the central station. Contracts are formed such that

グリーン
Green
belt
市 街areaUrban
地02 44 6 6 8 810 10 １２
12 km

Figure 1. Land-use planning in Munich

profits from development are evenly shared among developers (landowners), railway operators, and the
local government, institutionalizing sufficient infrastructure development through value capture.
In pursuit of realizing urbanity, new development must also devote a certain amount of floor-space
to residential space, not only improving compactness but also creating a city in which diverse people canlive. Furthermore, local policies require a wide range of rent settings, thereby providing a mix of sociallydiverse people and forming a city that can pass on an exceptional regional culture.
Lastly, Munich has policies to realize greenness, such as its regulations requiring the developmentof green areas along railways and accommodating the surrounding urban areas.
2-2. Integration measures for land use and transportation to enhance location efficiency(U.S. cities)
Transit-oriented development (TOD)(2) gave rise to a great movement in the United States in the latter
half of the 1990s. TOD is not simply a method of compact urban development formed around public(1) Hayashi, Yoshitsugu, Kenji Doi, Hirokazu Kato, and International Association of Traffic and Safety Sciences, eds. 2009. Toshi nokuoritei sutokku: Tochi riyo, ryokuchi, kotsu no togo senryaku [Quality Stock of Cities: Integrated strategy of land use, green space andtransportation]. Kajima Institute Publishing. (in Japanese)(2) TOD emphasizes development of public transportation nodes as the axis along which urban areas are formed, and induces development around these nodes. This allows economic activity to occur within walking distance of transportation nodes, placing focus onlifestyle opportunities and enhancing quality of life.

134｜Practicetransportation. Well-known features of TOD
include urban development within walking
distance of transit stations, high residential
density, and high functional diversity, but
underlying this a geographical layout are avariety of systems that aim to improve qualityof life and social justice.
One such system is location-efficientmortgage (LEM),(3) a policy tool for supporting
home acquisition in areas within walking dis-Figure 2. Examples of TOD implementation in Prince
George’s County, Maryland, USA

tance of public transportation by creating benefits given to residents who save personal andpublic transportation costs. This allows escape from over-reliance on automobiles. Discount train passes
are also offered to increase utilization of public transportation.
This has changed the definition of richness from one based on income to another based on time.
The dissemination of TOD schemes among US cities reflect change in citizens’ sense of values. Such achange is also necessary in Japan, particularly when one considers future constraints on public financing, the environment, and consensus formation.
2-3. Intensive land use for transportation networks and corridors (Utsunomiya, Japan)
Realizing TOD necessitates enhancement of the public transportation systems as its axes. Light rail transit systems (LRT) have been attracting international attention as methods for low-cost rapid transit. LRT
systems have been introduced in
Kamikawachi
Takanezawa
ImaichiＰ
Japan in recent years, significantly
changing strategies for urban land
usage.
Utsunomiya, having a population of 500,000, is a core city in thenorthern Tokyo metropolitan areathat has experienced significant
postwar development as an indus-

Technopolis
Center district

Ｐ

Ｔ

KanumaＴ

Utsunomiya Stn.

Ｔ

Ｐ ParkKiyoharadaiＴ

Motegi
MashikoRailway
Shinkansen line

LegendKinugawa

Ｐ

Mibu

Haga
Ichikai
MotegiKiyohara
Industrial

ＰBus

trial city. However, it features anextremely high level of automobile
dependency, which has resulted in
sprawled residential areas in its

LRTＰ

Ishibashi

For Tokyo

至 真岡市
Mooka

Ｔ
Ｐ

Shinkansen line
Railway
LRT
Main bus route
Community bus, demandtype traffic, etc.
Main road
Transit center
Park & Ride parking lot

Figure 3. LRT implementation plan (Plan for Securing Daily Life
Transportation) in Utsunomiya, Japan(3) LEM is a coordinated housing and transportation policy system that promotes the realization of TOD. To create benefits for residing
in areas accessible by public transportation, savings on automobile-related costs such as fuel, parking, and road tolls are calculated on a
by-area basis, and the amount saved is included when determining levels of homebuyer support.

A land utilization framework and transportation system for declining population｜135

suburbs, diffusion of urban functionality, and progressing hollowing out of the city center.
After the planned introduction of LRT has taken place, public transportation service in Utsunomiya
will be divided into four areas based on urban structure, with service provision adopted according to theconditions of each area. Utsunomiya aims to create a public transportation network servicing the entire
region through seamless coordination of the bus network with its core LRT system. In the urban center,automobile traffic will be curbed, while pedestrian and bicycle traffic will be developed and emphasized.
Introduction of LRT will also involve the conversion of major roads into transit malls, securing walkable
spaces in commercial areas to enhance pedestrian movement. At the same time, urban development will
aim to revitalize commercial districts along placed LRT routes by introducing LRT in conjunction while
also carrying out redevelopment projects. Lastly, composite development, such as the creation of an
attractive urban landscape and urban residential areas, will be required in Utsunomiya, in addition to
the city’s planned redevelopment projects.

3. Conclusions
In this project, we refer to the continual foundation of twenty-first century land and cities as a quality
stock that combines building clusters, green areas, and transportation systems. We have presented avision of urban retreat and reformation based around the formation of high-quality building clusters
with a unified look and of green area–public transportation corridors in a book Toshi no kuoritei sutokku[Quality Stock of Cities] (Kajima Institute Publishing).(1) This goes beyond the simple ideal of a compact
city to incorporate universal social goals and a vision featured on local societies, and provides specificmethods for realizing this vision.
Maintaining quality of life in the future will require coordination of integrated urban landscapes oftransportation, buildings, and green areas. This strategy will not be implementable if the future economy
declines too far; thus, this strategy should be taken as an urgent national priority.

4. Future outlook
The creation of quality stock that unifies building groups, green areas, and transportation systems canreverse urban structures, thereby lowering cost of living and improving the environment in the innercity. The result is development of the requirements for compacting and shrinking cities smartly, whichconstitutes necessary activities for stopping the “slumification” of Japanese cities and allowing the survival of the next generation.

136｜Practice

Quality of mobility required forsuper-aged cities
1. Background and goals
To enhance the quality of mobility in cities, it is necessary to construct a hierarchical network consistingof a fast mobility layer that supports rapid transportation between hubs, and a slow mobility layer that
supports low- and medium-speed transportation within hubs and towns. The needs for a safe and comfortable slow mobility layer will likely be particularly important in the context of a super-aged society,and the development of not only individual means of transportation but also the road environments
containing them will be vital. Ultra-compact, low-speed, short-range vehicles have been developed inrecent years to meet these needs, and some locations in the United States and elsewhere are using space
opened up by “road diets” (reducing the number/width of automobile lanes) to create travel space forultra-compact vehicles and bicycles. Such cases show a sense of road space utilization that is being fostered by a new mode of transportation developing between pedestrians, cyclists, and automobiles. Thiscan be taken as a suggestion of the possibilities for co-development of transportation methods, space,and infrastructure in a super-aged society.
In a project this year, we analyzed changes in values related to quality of mobility. Then we carriedout a pilot survey to use as a basis for anticipating future needs for slow mobility transportation methods, road spaces, and system development.
1-1. The viewpoint of this research
The idea of “slow mobility” used in this project is a new mode positioned between walking and otherforms of transportation (Fig. 1). Slow mobility is a medium- to slow-speed transportation method that
supports walking and emphasizes ease of getting off vehicles, rather than getting into them. Furthermore, it promotes human exchange and can therefore be viewed as a social system that supports andimproves regional vitality and quality of life. As Fig. 2 shows, the concept of “co-mobility” is defined
here as the combining of community and mobility by tying together not only places but people as well.
The ultra-compact vehicles that hold promise for use in slow mobility can be grouped under current law into four types: walking aid devices, bicycles, mopeds, and mini-cars. In this project, we focus
on the use of electric assist bicycles and moped-type micro-electric vehicles (hereinafter, micro-EVs).

Project Leader: Kenji Doi
Professor, Department of Global Architecture, Graduate School of Engineering, Osaka University

Quality of mobility required for super-aged cities｜137

Automobiles

s
ycle

Tax
is

orc
Mot

Regional qualityof life

es
Bus

Bic
ycl
es

Walking

Regional vitality

Conditions for slow mobility
Supports walking
Rather than being easy
to get on, is easy to get off

Interaction ofplacesHealth, security, andattractivenessConnects places

Co-mobility

Railways

Figure 1. Positioning of slow mobility
in urban transportation

Sense ofplace

Interaction ofpeopleMeeting places
Sense ofsolidarity

Figure 2. The co-mobility concept

2. Research content
2-1. Pilot survey in Mino, Gifu
The city of Mino (pop. 23,000) in Gifu Prefecture has long aimed
at town planning that supports cycling, but cycling has notcaught on due to its hilly terrain and the advancing age of its residents. In this study, we proposed a co-mobility strategy for
Mino’s slow life and cycling city concepts, and performed a pilot
survey aimed at its realization.
In the study, electric assist bicycles and micro-EVs wereloaned to participants. GPS tracking and participant journaling
were used for monitoring daytime and nighttime usage to investigate attitude changes, behavior, and the potential for lifestylechanges. The focus of the experiment was not to promote slow
mobility, but to investigate how subjects would select transporta-

Figure 3. Micro-EV decorated in
Mino-produced Japanese papertion modes when presented with five options (walking, cycling,riding electric assist bicycles, using micro-EVs, or driving automobiles), and to examining changes in
out-of-home behavior patterns.
The results of the experiment confirmed that offering these five modes of transportation resulted ina substantial widening of choices, thereby resulting in more frequent opportunities for out-of-homeactivity and a lowered reliance on automobiles. For example, the frequency of using personal mobility
vehicles such as micro-EVs and electric assist bicycles for commuting or business activities reached thesame combined values as that for automobiles. This raises the possibility that increased spread of personal mobility vehicles might lead to changes in mobility styles in regional cities that are currently experiencing over-reliance on personal car ownership.
Comparing usage frequencies of the five modes by distance traveled (Fig. 4), it is apparent thatmicro-EVs and electric assist bicycles were frequently used within a few kilometers distance, and thusthat developing environments of usage space within that range is key to the spread of personal mobility.
To hear the voices of also from a wider range of residents instead of just the experimental subjects,

138｜Practicea workshop was held during the pilot
survey, which provided an opportu-

100%
80%
Usage share

60%

Walking40%

Micro-EV + electric assist bicycles
Cars

20%

m

m

m
5–
6k

m
2–
3k

4–
5k

m
1–
2k

3–
4k

m
0–
1k

0%
Distance

Figure 4. Usage of transportation modes by distance in the pilot survey

nity for government and citizens tocome together to think of ways inwhich existing roads could be used
to expand the usage range andopportunities for personal mobility.
Various opinions were shared, suchas the need for reconsidering not
only transportation methods but also

the structure of cities and road infrastructure, as well as the need for reducing the number of automobile lanes (“road dieting”) to allow
space for personal mobility. We also proposed community buses and other specific forms of co-mobility
that provide meeting places to residents, connecting methods of public transportation and personaltransportation.
2-2. Pilot survey in Takamatsu, Kagawa
A running test was then performed in downtown Takamatsu city, in which a road diet was implemented
to create bicycle lanes, with the goal of investigating the influence of slow mobility on in-town travels.
Takamatsu was selected for this experiment because Mino has few commercial or public welfare facilities in its city center, complicating measurement of the effects on travels, and furthermore because it
would have been difficult to create slow mobility running spaces within the timeframe of the study.
In the experiment bicycle lanes were positioned as “slow mobility” lanes, and we verified the ease,safety, and potential for co-existence when micro-EVs shared lanes with bicycles (Fig. 5). The results
were as follows:(1) Bicycles and micro-EVs can travel together without conflict at speeds up to around 20 km/h.
(2) Implementation of simple road diets such as the establishment of slow mobility lanes lowered

No dedicated lane

Dedicated lane
Figure 5. The slow mobility lane experiment in Takamatsu City

Quality of mobility required for super-aged cities｜139

automobile running speeds by 3–8 km/h, reducing the speed difference between vehicle types.
(3) Safety was improved in areas where slow mobility lanes were established (i.e., where road dieting was implemented) over areas where they were not.

3. Conclusions
From the results of our investigation of changes in values regarding quality of mobility and from ourcomprehensive investigation of super-aged society-related factors, including activity needs and desires
for improvement to transportation, we found a definite trend toward safety, health, and the environment, and furthermore found that such value changes manifested needs for road diets, speed reduction,and slow, personal forms of mobility. The results of pilot surveys suggest that providing such new methods of mobility has the potential to change mobility styles in regional cities with a limited selection oftransportation modes, and they confirm the utility of slow mobility lanes as a way of developing sharedrunning space.

4. Future outlook
Developing countries in Asia and other regions require methods of traffic reduction on the premise of
traffic with a variety of vehicle types, including motorcycles. The co-mobility strategies proposed in thisproject, which combines road dieting, speed reduction, and slow, personal forms of transportation, arelikely to provide important clues regarding methods for safe, sustainable transportation in other countries with various traffic situations.

140｜PracticeUrban development from parking lots
considering inner-city parking density
1. Background and goals
Automobiles are now a vital means of transportation for the elderly and persons with disabilities, to theextent that in rural parts of Japan, there are over 0.8 automobiles for person. Every automobile requires
around 15 m2 of parking space, both at the point of departure and at the destination; this is approximately the same amount of space per person in an average Japanese residence. As a consequence, parking spaces in many cities currently occupy approximately 20–30% of the inner-city surface area. In atypical planned city, parks occupy approximately 3% of the surface area and roads approximately 25%.
Accordingly, the area required for parking cannot be ignored in urban planning.

2. Research content
In this project, emphasis is placed on three “D”s and one “M.” The first “D” is “density”, which refers to
how many parking spaces are needed in inner cities. The second “D” is for “disposition,” which refers towhere parking lots should be placed. The third “D” is for “design,” which refers to specifically what kindof parking lots should be provided. The “M” in this study is “management”, which refers to how to manage parking lots. Each of these four aspects must be carefully considered. This paper presents an overview of research regarding density, the most fundamental of the four points described above.
2-1. Level of parking needed in urban areas
To investigate the required scale of parking lots needed in inner-city areas, we performed on-site investigations in Japan, the United States, United Kingdom and Germany (Fig. 1). We found that the cities
with the most parking spaces available were Houston and Dallas in the United States, which had over
200 spaces/ha. The locations with the least parking were central London and Westminster.
As for Japanese cities, downtown Yokohama, Shibuya, Yokosuka, Odawara, Shinjuku andTachikawa have approximately 50–70 spaces/ha. There were slightly more in Chiba, Kofu and Saga,
which had approximately 75–80 spaces/ha, and relatively new towns located some distance from Tokyo
such as Chiba New Town and Tsukuba New Town had around 100 spaces/ha, thanks to the numerous
large-scale parking facilities in those areas. Note that most locations have approximately 60–70
spaces/ha, which is thought to be because local government ordinances regarding parking spaces inJapan mandate a nearly identical level.
Project Leader: Takayuki Kishii
Professor, Department of Civil Engineering, College of Science and Technology, Nihon University

Urban development from parking lots considering inner-city parking density｜141

250

United States
Germany
United Kingdom
ThailandJapan
Japan (Kofu, Saga)

Parking density (spaces/ha)

200

212

216

156

150
120
110
97

100

48

50
30

53

59

60

60

60

67

68

73

73

75

76

78

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w
To
wn
Po
rtl
an
d
Ba
ng
ko
k
Da
lla
s
Ho
us
to
n

0

Figure 1. Parking density
Japan: Designated parking development districts;
USA: Inner-city business improvement districts; Europe: Inner loop areas(Locations that clearly seem to be privately owned garages are excluded)

2-2. Comparison of local government regulations regarding parking spaces
The primary reason for the situation in Japan is established by local government ordinances regarding
parking spaces. Table 1 shows an international comparison of similar local government regulations inother countries. Houston, which has the largest number of parking spaces, has established requirements
for a minimum number of available spaces. The parking requirements in downtown Houston are on parwith those of suburban shopping centers (around 200 spaces/ha), and furthermore specify that at least
75% of parking spaces should be provided on site, meaning that there are ample parking spaces even in
inner-city areas.
Among the areas studied, London has the fewest parking spaces. It places an upper limit on thenumber of parking spaces that can be created. On the other hand, Japan has established lower limits like
Houston, so while there is some variation between industrial and commercial areas, requirements generally mandate 30–60 spaces/ha. Other cities examined, such as Portland, Cambridge and Frankfurt,
have local government regulations regarding parking spaces that fall somewhere between those of
Houston and Japan.
2-3. Parking situation in overseas cities
Differences in the laws and standards of various countries have a strong effect on their parking circumstances. We therefore next compared two cities closely associated with this project and introduce theirmain features below.

142｜PracticeTable 1. Comparison of local government regulations pertaining to parking availability standards(offices, commercial)

Houston(At least 75% on site)

Portland(Core Area, converted as NFA = 0.6

Lower
limit

OfficesCommercial

269 spaces/ha
431–538 spaces/ha

Upper
limit

OfficesCommercial

75 spaces/ha
180–358 spaces/ha

Upper
limit

OfficesWithin CPZ
Commercial 100 spaces/ha + disabledparking
Disabled parking only

Outside CPZ
250 spaces/ha + disabled parking
200 spaces/ha

Upper
limit

OfficesCommercial

286 spaces/ha
333–666 spaces/ha

GFA)

Cambridge(Within the inner-city controlled
parking zone (CPZ))

Frankfurt (FF)(Inner city, 90% cash payment)

Japan

Lower
limit

30–60 spaces/haLondon

Upper
limit

7 spaces/ha

Houston, Texas
Houston is the fourth largest city in the United States. Most of its downtown is contained within a 2×2
km area. Within that area are approximately 100,000 parking spaces, for a density of 216 spaces/ha. Thisis approximately the same level of parking service found in large-scale suburban retail stores. There are
90 multilevel parking garages with approximately 800 parking spaces each. There are also approximately
300 surface lots.
Portland, Oregon
Portland is a public transportation-oriented city with an approximately 2×1 km downtown area sandwiched between a river and an expressway. Similar to Houston, the streets in inner-city Portland are
generally in a grid pattern, as are streets in many American cities that were planned out during the pioneer days. As a result, roads alone account for approximately 40% of land use in the downtown area. The
average parking density is approximately 120 spaces/ha, a density far higher than that of Japan, despite
the city’s image as being highly oriented toward public transportation.

3. Conclusions
Looking at the parking situation of major cities in Japan and overseas, the density of parking spaces inhighly automobile-oriented societies is approximately 200 spaces/ha, but in cities with highly developed
public transportation a density of around 60 spaces/ha is sufficient. Between those extremes, public
transportation-oriented American cities and local cities in Japan seem to have around 90–120 spaces/ha.

Urban development from parking lots considering inner-city parking density｜143

However, effort is required to maintain the density at these levels, despite the fact that the results ofderiving a relational equation for standards of local government regulations regarding parking spaceand parking density show that insofar as standards are adhered to in local Japanese cities, this density is
maintained. This is because when parking space availability follows demand, the density soon increases
to 150 spaces/ha. In such cases, half of inner-city areas become devoted to parking and buildings consequently seem to exist in a sea of parking lots. Our hope is that this project will contribute to preventing
such an outcome through the development of attractive, functional urban spaces.

4. Future outlook
In the major cities of Japan, even when accounting for illegal parking, there is a surplus of inner-cityparking spaces. This indicates the need for a more flexible approach to local government regulations
regarding parking spaces (revising basic units, establishing mechanisms for utilization of parking spaces
in remote locations, providing alternative parking through cost-burden sharing, etc.) and proactive
aggregation of existing parking lots. We also believe there is a need to consider drastic changes to laws
pertaining to parking lots, such as by adding provisions that place upper limits on the number ofrequired on-site parking spaces. The handling of parking spaces has a large effect on inner-city land use
and thus will require greater attention in the future.

144｜Practice

Practical optimal signal control emphasizing
pedestrian road crossing realities
1. Background and goals
Currently, pedestrians do not sufficiently understand the meaning of the signals at pedestrian crossings,
and as a result, actual pedestrian behavior is not necessarily the same as that assumed by traffic laws.
This has been noted as one factor accounting for pedestrians not completely crossing the road by thetime crossing signals turn red, affecting traffic safety and smoothness by causing complications withvehicles turning left or right.
This study is a report of an actual road experiment in which we investigate and analyze changes inpedestrian road-crossing behavior after mounting auxiliary equipment to a traffic signal that allows
pedestrians to clearly understand the amount of time remaining to cross the road.
The experiment first evaluated the effect of displays indicating time remaining for road crossing byanalyzing videos of an actual crosswalk. We then performed an experiment in which music by the composer Keiichiro Shibuya was played during road crossings as a method of promoting behavioral change
in pedestrian psychology.

2. Research content
2-1. The effect of installing crossing signals with countdown displays
We installed crossing signals with countdown displays as shown in Fig. 1 at actual pedestrian crossings,
and evaluated their effect in a pilot survey (Table 1).
Figure 2 shows changes in the ratio of pedestrians who did not complete road crossing by the time
Table 1. Evaluation by pilot survey (2005)
Item

Figure 1. Pedestrian crossing
signal with countdown display

Description

Experimental
intersections

Tokyo: Ginza 2-chome, Ginza 5-chome, Omori
Yokohama: Honcho 1-chome, MM2

Experimental period

9 December 2005 (Friday) - (about 2 months)

Survey andobservation period

Before the experiment: 18, 25, 28 November 2005
During the experiment: 14, 16, 19 December 2005

Investigation methods

Videos: 3000–8000 pedestrians at each intersection
Surveys: About 100 pedestrians at each intersection

Project Leader: Masahiko Katakura
Professor Emeritus, Tokyo Metropolitan University

Practical optimal signal control emphasizing pedestrian road crossing realities｜145

Residual rate [%]Beforeexperiments

35
30

Pedestrian green (PG)

Duringexperiments

25
20

Pedestrian
flashing
green (PF) Pedestrian red

15

Green

10
5
0

Ginza
2-chomeGinza
5-chome

Honcho1-chome

MM2

Figure 2. Effects of countdown display

the signal turned red (the residual rate) at eachcrossing with a countdown display. In all cases, weverified a reduction in the residual rate ranging
from a few percent to as much as 10%.

Flashing
Time traversed in 1 m/s
Figure 3. Green completion and green flashingcompletion methods

Crossing speed (m/sec)

3.5

Green completion method(during experiment)
Figure 3 shows the results for two types of
2.5
Green completion methodcountdown, a “green completion method” that
(before experiment)
1.5
shows the decreasing amount of remaining timeand a “green flashing completion method” that
0.5
shows the end of the crossing period. Both had-30 -25 -20 -15 -10 -5
05
Crossing
start
time
(sec)
Red start time
approximately equal effects in reducing the residual rate. However, as shown in Fig. 4, the green
Figure 4. Change in crossing speed
completion method saw a rapid increase in pedestrian crossing speed during the latter half of the crossing, indicating the possibility that pedestrians feelrushed. In contrast, there is no significant difference in speed between the former and latter half ofcrossing when using the green flashing completion method. We presume that this is due to a reductionin the number of pedestrians who started crossing later than they should; therefore, we consider thegreen flashing completion method to be superior.
The results of a survey indicated that with the exception of young people (age 13 to 24 years), over
80% of pedestrians who understood the meaning of the countdown display found it helpful. We also
found that placing the countdown display and the pedestrian crossing icon on separate panels (Fig. 1)
increased the recognition rate of the display among pedestrians, as compared to when the icon and display were shown together.
In 2006, we experimentally installed these crossing signals at four intersections (Ginza 5-chome,
MM2, Ginza 4-chome, and Tsurumi Keisatsusho-mae) for pedestrian crossings ranging from 13 to 38 m
in length, conducted a questionnaire, and performed video observations of approximately 16,000 pedestrians. Results of the questionnaire performed at the MM2 and Ginza 4-chome intersections were largely
positive in terms of the subjective evaluations by pedestrians. However, a statistically significant reduction in the number of pedestrians not completing road crossing by the time the signal turned red wasseen only under the green flashing completion method at the Ginza 4-chome intersection; no effect was146｜Practice

Crossing distance, 38 m (Tsurumi Keisatsusho-mae)

Average walking speed (m/sec)
3.5

Crossing distance, 24 m (Ginza 4-chome)

3.0

Crossing distance, 22 m (MM2)

2.5

1.0

-0.50

Pedestrian red start2-2. The effect of installing

0.5

Density: 0.0 to 0.2 people/m2-1.00

of the crossing, in the second half ofthe crossing (Fig. 5).

1.5

Gauge decrease start-1.50

increase in pedestrian walking speed,which was proportional to the length

2.0

Crossing distance, 13 m (Ginza 5-chome)

verified at the other intersections. Yet,
we were able to confirm a significant

0.00

crossing signals with
audible cues
We installed crossing signals with

0.0

Crossing start time

audible cues, which played music
when the signal was green, to investi-

Figure 5. Crossing distance and average crossing speed(during green flashing completion)gate whether the installation changed pedestrian crossing behavior by psychologically promoting an
increased crossing speed when there was little time remaining to cross, and by preventing pedestrians
from initiating crossing when the green signal was flashing. The music played was composed by
Keiichiro Shibuya, an established Japanese musician.
The three compositions respectively aimed at promoting a comfortable walking pace, increasing
crossing speed, and warning pedestrians to prevent intrusion into the crossing. The trumpet-type speakers that can be installed into pedestrian crossing signals are very limited in the range of frequencies andwaveforms they can produce, so compositions that would be easily remembered and not tiresome underthese conditions had to be produced. In other words, the compositions could not simply be sinusoidal
waves such as the loud tone played when a television station is off the air, but rather had to successfully
employ square waves for attacks and reverberations to present a rich sound that could be clearly heard.
Table 2 shows an overview of theTable 2. Overview of investigation and the acquired data
investigation and the obtained data. As
Observation
PeopleTable 3 shows, the residual rates over all
Music
Video datemeasurement times were 18.7% withoutmusic, but fell to 13.9% when the music
was played, representing a statistically significant decrease. We found no differencein the time that pedestrians initiated crossing after the light turned green based on
the presence or absence of music; however,there was a difference in the time thatpedestrians completed crossing whenmusic was played. This indicates that themusic decreased the residual rates. As Fig.
6 indicates, this is due to an increased

locationcrossing

Ginza
4-chomeNone
Yes

30 October 2007 (Tuesday)
18 March 2008 (Tuesday)

1929
1804

Table 3. Residual rate and remaining time
Music

None

Yes

Crossing count [people]

1929

1804

Residual amount [people]

361

251

Residual rate [%]

18.7

13.9

Average remaining time [sec]

5.3

4.4

Maximum remaining time [sec]

16.3

18.8

Significance0.037

Practical optimal signal control emphasizing pedestrian road crossing realities｜147

3.0

50%

2.5

40%
35%

2.0

30%
1.5

25%
20%

Without music

1.0

15%

With music
Critical crossing speed

0.5

10%

Percentage of all people crossing [%] (vertical bar)

Average walking speed [m/sec] (broken line)

45%

5%
0.0

0%
-40

-36

-32

-28

-24

-20

-16

-12

-8

-4

0

Crossing start time (0 = PR start time)

Figure 6. Average walking speed at crossing start timecrossing speed. Furthermore, we found that overall, the presence of music prevented approximately 40
people from prematurely starting to cross. We verified a similar effect in an investigation of an intersection at Shin-Yokohama 2-chome.

3. Conclusions
The pieces of music by Mr. Shibuya that were used in the present study were composed with the goal ofbeing easy to remember and hum along to, and were clear, distinctive, and easily heard over the soundof traffic. It is likely that pedestrian crossing signals that play such music are not only accepted more easily by pedestrians, but also exhibit tangible effects of reduced residual rate and increased walking speed,providing an effective improvement to current crosswalk walking behavior.

4. Future outlook
This research indicated that pedestrian crossing signals equipped with appropriate music-playing functionality can lead to proper pedestrian crossing behavior. We hope that future studies will verify theeffectiveness of crossing signals with audible music cues under a variety of road and traffic conditions
and in various acoustic environments, and that the installation of such equipment at many intersections
will aid efforts to improve pedestrian safety and smooth traffic.

148｜PracticeSignificant reduction of cycle length via a
two-stage crossing system
1. Background and goals
The cycle lengths (1) of signals at large
intersections in Japan are much longer••

than those in Europe. This can irritatepedestrians, who must wait a long time
for crossing signals to change at intersections. In addition to intersection traffic
demand, the amount of time that pedestrians require to cross intersections has alarge effect on determining cycle lengths.
One method to reduce cycle lengths currently attracting attention is the introduction of two-stage crossings, where acentral island in the middle of a crosswalk is established and pedestrian crossing signals allow crossing independently
to either side of the island (Fig. 1, 2).
In this project, we performed a pilot
survey for reducing cycle lengths throughthe introduction of two-stage crossings.
We first accumulated research throughon-site investigations and simulation
analysis. Based on this, and with the support of road and traffic administrators,•

A central island is established in the crossing
A pedestrian crossing signal is added tothe central island
A design and control method where pedestrians
can wait (as opposed to “are made to wait”) in

the central island
Slower-walking pedestrians can wait
safely in the central island• Allows signal cycle length reduction• Pedestrian signal displays can be divided•

at the central island

Figure 1. What is a two-stage crossing?

Two-stage通常
display division

In the two-stage crossing method, a green signal is displayed in regions where cars turning right cannot passThis increases the space and time available for pedestrians in crosswalks,
increasing pedestrian passage rates
2

Figure 2. Two-stage crossings and signal display division

we installed two-stage crossings at the Kasumigaseki 2-chome intersection in downtown Tokyo, Japan.

Project Leader: Hitoshi Ieda
Professor, Graduate School of Engineering, The University of Tokyo / National Graduate Institute for Policy Studies(1) Signal cycle length: The time for the light on a traffic signal to cycle through green, yellow, red, and back to green. At large intersections in Japan, the signal cycle length is normally from 120 to 150 seconds.

Significant reduction of cycle length via a two-stage crossing system｜149

2. Research content
In this project we (1) planned and implemented a public
relations strategy, (2) performed a pilot survey and investigation, and (3) verified the effects of the experiment.
2-1. Planning and implementation of a public
relations strategy
At first glance it might seem that two-stage crossings areeven more inconvenient for pedestrians because the central

3

Figure 3. The public relations logo
構内の３箇所に説明パネルを展示

island increases the number of times they must wait for signals, among other reasons. We therefore performed various
strategic public relations activities so that users would better
understand the intent of two-stage crossings.
Specifically, we created the “Easy Crossing Project
KASUMIGA SEKI” campaign (Fig. 3), and (1) installed
explanatory panels in the Kasumigaseki subway station (Fig.
4), (2) distributed leaflets to government agencies, public
offices, and pedestrians in the area, (3) created a website foranswering questions and collecting opinions, and (4) advertised to the mailing lists of various organizations.
2-2. Implementation of the pilot survey
and investigation
The pilot survey was performed starting on 13
January 2009 from 10:00 to 15:00 on weekdays
for one month. To ensure complete safety, we stationed a traffic guide in the central island whohelped guide pedestrians (Fig. 5).
We began the experiment using a cycle
length of 75 seconds (approximately one-half thenormal time of 140 seconds), but as it became

Figure 4. Explanatory panels weredisplayed at three locations in the station

Ministry of
Finance

Ministry ofForeign Affairs

Ministry ofAgriculture,
Forestry and
Fisheries

Ministry of Economy,
Trade and Industry

Before theexperimentDuring theexperiment

Divided signals

apparent that this caused pedestrians crossing in
the counterclockwise (CCW) direction to rush,
we extended the cycle length to 100 seconds from
9 February. Note that for the duration of theexperiment, the cycle lengths at surrounding
intersections were set to 150 seconds.
We conducted the following two investigations to measure the effects of the experiment:

Placement of traffic guides Utilizing the central island

Figure 5. The pilot survey

5

150｜Practice(1) Video survey: We videotaped the crossing, and from this we measured factors such as pedestrian wait times, walking speed, how much pedestrians ignored signals, and situations when pedestrians and automobiles came into conflict.
(2) Questionnaire survey: we conducted a questionnaire survey to determine pedestrian psychology at crossings and degree of acceptance of the new crossing method.
2-3. Verification of the effect(1) Results of the video survey
Video analysis of pedestrian
behavior yielded the following
results (Table 1). Note that in theanalysis we weighted the spacing
between arrival times of individual pedestrians, and calculated
each index as a normalized uniform arrival distribution withconstant density.

Table 1. Analysis results (comparison with a 140-second cycle length)
Measurement item

Two-stage crossing Two-stage crossing(75 seconds)(100 seconds)(1) Average pedestrian wait time

CW: 53% decrease
CCW: 18% decrease

CW: 54% decrease
CCW: 6% decrease(2) Average walking speed

CW:
6% increase
CCW: 26% increase

CW:
CCW:

(3) Pedestrians in crossing after signal
changes to red

CW:
3% decrease
CCW: 61% increase

CW:
8% decrease
CCW: 30% increase(3)’ 95th percentile walking time after
signal changes to red

CW: 67% decrease
CCW: 20% increase

CW: 74% decrease
CCW: 12% decrease(4) Pedestrians in central waiting island

CW:
0%
CCW: 34%

CW:
0%
CCW: 28%

3% increase
9% increase(a) Changes in pedestrian wait times
We found that average pedestrian wait times decreased in all scenarios. Specifically, with a cycle lengthof 75 seconds (C75) the wait time for pedestrians crossing in the clockwise direction (CW) was
decreased by 53% and that for pedestrians crossing in the CCW direction was decreased by 18%. With acycle length of 100 seconds (C100), the CW decrease was 54% and the CCW decrease was 6%.
(b) Changes in walking speed
We next examined average pedestrian walking speed and found that with C75 there was a 6% CW
increase and a particularly high 26% CCW increase. With C100, there was a significantly smaller
increase in walking speed in both directions of just 3% CW and 9% CCW.
(c) Changes in the ratio of pedestrians remaining in the crosswalk and in pedestrian walking time after
signal change
We also compared the ratio of pedestrians remaining in the crosswalk when the signal became red,and found that while there was a 3% CW decrease with C75, there was a very large 61% CCW
increase. The CCW increase was lowered to 30% with C100. This is still not a low number, but when
we compare 95th percentile values of walking time after signal change for pedestrians remaining in
the crosswalk, we found that although with C75 there was a 20% CCW increase, with C100 there wasa 12% CCW decrease. This indicates that with C100 pedestrians are clearing out of the crosswalk
faster than with C75. When we interviewed the traffic guides regarding this, they reported that many

Significant reduction of cycle length via a two-stage crossing system｜151

CCW-walking pedestrians ignored signals when the cycle length was 75 seconds, but that this was not
a problem at 100 seconds.
(2) Questionnaire survey results
Responses to the questions “Were you able to cross with less waiting time than at other intersections?”
and “Were you able to cross without hurrying?” showed trends similar to those found as a result of video
analysis. Responses to the question “Do you think that crosswalks with a central waiting island and separate crossing signals like those used in this experiment should be applied to various other intersections?” were around 70% positive for pedestrians crossing in each direction, indicating a high level ofpedestrian acceptance of two-stage crossings. However, slightly less than 40% of respondents reported
difficulty understanding how to cross the two-stage crossings, indicating that this is a problem that must
be addressed.

3. Conclusions
Results of the analysis of the pilot survey performed in this project indicate that cycle length reduction
via two-stage crossings is an extremely effective measure for reducing automobile and pedestrian wait
times and irritation. Considering that nearly 70% of pedestrians had positive feelings toward this experiment, we believe that there is a high probability that the introduction of two-stage crossings in Japan
will be accepted to reduce cycle times. We note, however, that negative opinions related to pedestrian
confusion were expressed regarding the new crossings. Some pedestrians would try to cross them in theusual manner, not noticing the change in signals.
In the future, it will be necessary to accumulate experience at a variety of intersections to discovermethods by which two-stage crossings can be better understood, such as by changing crossing structure,adjusting the position and size of signals, changing how remaining time and wait times are displayed, or
providing road lighting and voice guidance.

4. Future outlook
Since the implementation of this project, both road and traffic administrators have gained an understanding of the effectiveness of two-stage crossings, and the implementation of these systems will beconsidered at some locations. However, the true effect of cycle length reduction via the introduction of
two-stage crossings will only be seen after the verification of network effects through their introduction
at multiple locations. It will therefore be essential in the future to select locations where this method canbe applied as a network, and to perform trial implementation in those areas. As we head toward theTokyo Olympic Games in 2020, we must ensure that road intersections in Japan do not pose an international embarrassment, and that we continue to make changes for their increasingly comfortable use byboth pedestrians and automobiles.

152｜Practice

A study on the practical deployment andpromotion of safe and ecological roundabouts
1. Background and goals
Countless accidents involving head-on collisions and vehicles turning against traffic occur at road intersections, regardless of whether traffic signals are in place. Even when installed as a safety measure, traffic
signals do not always prevent accidents from occurring when the signals change or when drivers ignore
them. Therefore, in some cases, signalization does not provide a fundamental solution to the problem.
When installed at intersections with low traffic volume, traffic signals can even cause problems such as
delays and increased environmental load. To search for solutions to these issues, the current project aims
toward the practical deployment of modern roundabouts in Japan. As part of these efforts, the H188
Project was launched in 2009, with the following goals.
1) To conduct field operational tests in cooperation with government organizations, thereby collecting a variety of empirical data associated with introducing roundabouts to Japan and preparing an environment for their full-scale introduction.
2) To collect data on user behavior before and after the introduction of roundabouts at intersections, thereby accumulating empirical data for the advancement of technical findings related tothe planning and design of roundabouts in Japan. Furthermore, to conduct quantitative evaluation of the effects of roundabouts by comparison of data before and after their introduction.
3) To perform ongoing promotional activities such as workshops and seminars for the implementation of roundabouts.
4) To propose specific plans, designs and technologies related to roundabouts, and to participate intechnical planning of field operational tests. Through this, to accumulate and summarize experience with cases of roundabout conversion.

2. Research content
2-1. Analysis of user behavior through a mock roundabout on testing grounds
In the H188 Project of 2009, a mock modern roundabout was established at the Tomakomai Test Trackof the Civil Engineering Research Institute for Cold Region, and technical empirical data were collected
on user behavior related to designs and operational methods such as structural geometries, road signs,
and markings. These data were then used to perform analysis of safety and efficiency, enabling the
Project Leader: Hideki Nakamura
Professor, Department of Environmental Engineering and Architecture, Graduate School of Environmental Studies, Nagoya University

A study on the practical deployment and promotion of safe and ecological roundabouts｜153

acquisition of structural and operational knowledge.
2-2. Field operational road test at a roundabout in Azuma-cho, Iida City
In the H2292 project, the project team cooperated with Iida City in Nagano Prefecture and installed
road markings and various safety devices in an existing rotary intersection in the Azuma-cho district,without changing the intersection’s physical structure. Over the 42 days between November 1 andDecember 12, 2010, a field operational test was performed to verify the effects of structural improvements to an actual roundabout incorporating the latest design ideas (Fig. 1). There was a high degree ofsupport from local authorities and residents regarding the structure and operation of the modern
roundabout developed on the basis of the most recent technical knowledge. This furthermore allowed
for verification of the safety and traffic-smoothing features of modern roundabouts on actual Japaneseroads.

(a) Before the test (Photo by Iida City)(b) After the test (Photo by Highway Planning, Inc.)

Figure 1. The roundabout on which field operational tests were performed in 2010; Azuma-cho, Iida City,
Nagano Prefecture

2-3. Field operational test of a pedestrian detection system implementing light-emitting
road studs in Azuma-cho
Because the 2010 field operational test was evaluated highly, Iida City decided not to revert the roundabout to its previous layout for the next year, and the roundabout was left in generally the same condition as in the field operational test. In 2011, various improvements to the intersection were made, such

154｜Practice

as modifying the location of crosswalks and installing structures at corners where semi-permanent roadcones had been previously installed during the field operational test. Immediate relocation of somecrosswalks was difficult for a variety of reasons, and as a result in some locations the distance between
the circulatory roadway and crosswalks increased. For these locations in particular there were concerns
about pedestrian safety. Therefore, with the cooperation of Iida City and the ITS Laboratory at the
National Institute for Land and Infrastructure Management, the H2303 project was conducted. In thisproject, a system of light-emitting road studs was installed at the crosswalks of roundabout entries/exits
for pedestrian detection in Azuma-cho, and an experiment was performed to verify the system’s safety
and functionality. The results confirmed that there was improved pedestrian safety during road crossing,and the system received many positive evaluations from users.
2-4. Japan’s first conversion of a signalized intersection to a modern roundabout in
Towa-cho, Iida City
As a result of the various field operational tests regarding the proposals and verifications performed in“A study on the practical deployment and promotion of safe and ecological roundabouts (H188/H2292/
H2303),” conducted between 2009 and 2011 in cooperation with related government agencies and local
residents, in 2012 a signalized intersection in the Towa-cho district in Iida City was converted to a modern roundabout (Fig. 2). This was a groundbreaking initiative that marked the first time that traffic signals had been removed and an intersection converted into a roundabout in Japan, making it anextremely valuable case study. In the H2420 project “A study on social implementation and promotionof roundabouts,” which started in 2012, a technical investigation of this conversion was performed, anddata from before the conversion were collected. Furthermore, methods were investigated for convertingintersections into roundabouts while still allowing traffic in operation, and experiences during the construction and operation were recorded. On March 24, 2013, a modern roundabout that incorporated thelatest technologies investigated and proposed by this project was finally opened in Towa-cho. The(a) Before construction (2012)(b) Completion (March 2013)

Figure 2. Conversion of a signalized intersection to a modern roundabout; Towa-cho, Iida City, Nagano Prefecture(Photo by Iida Cable Television)

A study on the practical deployment and promotion of safe and ecological roundabouts｜155

roundabout featured a central island with a stepped apron construction, splitter islands at entries/exits,
and a two-stage crosswalk, all Japan firsts.
2-5. Pre- and post-conversion comparison of the roundabout in Towa-cho
In the H2534 project, user behavior was compared before and after the conversion of the Towa-chointersection to a modern roundabout. The results confirmed significant reductions in average vehicle
delays and average pedestrian travel times following the conversion to a roundabout. When the intersection was signalized, intersection entry speeds and vehicle pass-through speeds were high and varied
greatly, but following the conversion to a roundabout, entry speeds were verified to be lower and morestable. A much lower level of danger was verified for collisions between vehicles, especially those turning against traffic.
2-6. Roundabout planning, technical proposals for field operational tests, androundabout promotion
Since its start, this project has continued to work toward the planning and design of roundabout conversions throughout Japan, as well as toward proposals, support, and promotion for further field operational tests. In the process, the project has attempted to grasp both citizens’ needs and practical businessneeds, and as a result was selected by the Ministry of Land, Infrastructure, Transport and Tourism toperform further operational tests in Karuizawa-cho in Nagano Prefecture, Yaizu City in Shizuoka Prefecture, and Moriyama City in Shiga Prefecture. Roundabout conversions were successfully implemented through these operational tests and large effects were verified. During the fiscal year ending inMarch 2015, additional roundabouts will be implemented at unsignalized intersections in the cities of
Suzaka and Azumino in Nagano Prefecture. We have continued to conduct seminars throughout Japanto deepen understanding of roundabouts, and in particular drew many attendees and much attention to
our “Roundabout Summit” at Iida City in January, 2014. At that summit, formation of a “Roundabout
Promotion Council” was declared, comprising the heads of seven regional governments.

3. Conclusions
While at first it took a long time to obtain understanding of roundabouts in Japan, the present research
and activities have helped widely position roundabouts as a vital part of safe city planning among government agencies, engineers, and area residents. This has led to serious consideration of the introduction of roundabouts throughout the country, and with the amendments to the Road Traffic Law in June
2013, there has been no small amount of attention brought to the national level. In the future it will benecessary to continue on with these efforts to promote the dissemination of appropriate technologies
and to continue the collection and analysis of data related to the currently ongoing cases.

156｜Practice

A study on the role and limitations ofmotorcycles as a means of urban transport inSoutheast Asia
1. Background and goals
Motorcycle ownership and use has advanced rapidly in Southeast Asian regions in recent years, making
motorcycles a major mode of urban transport. Because cities in developed countries have not previously
experienced such a phenomenon, the positioning of motorcycles with regards to traffic planning, designof transportation facilities, and transport operation is unclear, and focus has instead been placed on thenegative aspects of motorcycles, such as increases in traffic accidents. However, motorcycles are compact, highly maneuverable, and have a relatively low environmental impact; thus, they may be a potentially beneficial mode of urban transportation by clarifying their positioning.
Given this situation, this project investigated the actual conditions of motorcycle usage from a variety of viewpoints and elucidated the issue. Specifically, we investigated subjects such as trends in motorcycle dissemination, the effects of motorcycles on traffic flow, traffic operation at intersections according
to the motorcycle ratio, usage of motorcycles as taxis and delivery vehicles, and efforts toward increasing
motorcycle safety. Through on-site investigations, analysis of statistical data, and interviews with expertsin Thailand, Cambodia, and Vietnam, we were able to obtain much new knowledge.
As a representative example, below we present our findings resulting from investigations on actual
traffic operation at intersections according to motorcycle ratios. Based on our findings, we make a proposal for efficient traffic operation at intersections and analyze the effects of conversion from motorcycles to four-wheeled vehicles on transport volumes.

2. Research content
2-1. Investigation of traffic operation at intersections according to motorcycle ratio and a
proposal for efficient operation
Intersections are operated in a variety of ways according to the ratio of motorcycles to overall traffic volume. We recorded videos to perform a traffic survey in Bangkok, Chiang Mai, and Phnom Penh, threecities with different motorcycle ratios and different methods for traffic operation at intersections. We
performed a quantitative evaluation of each intersection’s traffic capacity(1) and investigated the
Project Leader: Atsushi Fukuda
Professor, Department of Transportation Systems Engineering, College of Science and Technology, Nihon University(1) Intersection traffic capacity: At a single-path portion of a road, capacity is taken to be the number of vehicles that can pass throughthat location in one hour. At intersections, however, traffic passes through from different directions, reducing the number of vehicles thatcan pass. It is therefore important to determine intersection capacities.

A study on the role and limitations of motorcycles as a means of urban transport in Southeast Asia｜157

Motorcycle-onlylaneMotorcycle signal
waiting area

Standard：Motorcycle：Passenger
vehicleFigure 1. Three types of intersection configurations

dard intersections with intersections that have a designated area
for motorcycles to wait for traffic
signal changes, the latter have thenegative effect of pushing back thestop line for four-wheeled vehicles,
delaying their start times. However, there was a positive effect inthat allowing motorcycles to collect at the front of signal wait areas
reduced the number of motorcycles running between cars. We thus
found that in situations where
there is a low motorcycle ratio,

Saturated flow rate (four-wheeled vehicles only)intersection configurations that were most efficient for traffic flow control according to the variations inmotorcycle ratio.
We found that an increased number of motorcycles traveling alongside four-wheeled vehicles at astandard intersection can impede traffic of four-wheeled vehicles. In contrast, we found that lanesplitting motorcycles did not have an effect on the operation of four-wheeled vehicles.
Therefore, comparing stan(pcu/lane/h)1850
Standard

Bangkok

Chiang Mai

Phnom Penh

Motorcycle signal waiting area

1800
Motorcycle-only lane

1750
1700
1650

0

0.2

0.4

0.6

Motorcycle ratio

There is an appropriate method according to the motorcycle ratio
for traffic operation at intersections.
Saturated flow rate on the vertical axis refers to the maximum number of automobiles that can flow into
an intersection without travel interruption during a green light. This is used as the base value for finding
intersection capacity.

Figure 2. Changes in intersection capacity due to motorcycle ratio

158｜Practicestandard intersections may allow for more efficient traffic flow, but the opposite may be the case withhigher ratios. We observed an effect due to establishing motorcycle-priority lanes and to the narrowed
lanes for four-wheeled vehicles. This indicates that the optimal intersection configuration may differ
according to motorcycle ratios.
2-2. Impact on transport volumes due to conversion from motorcycles to four-wheeledvehiclesThere is an assumption that increased economic development will promote four-wheeled vehicle usage,
thus lowering motorcycle usage ratios in cities where these ratios are currently high. We therefore analyzed the potential effects of this conversion from the viewpoint of transport volume.
In Bangkok, each motorcycle carries on average 1.2 people, while each automobile carries on average about 1.5. Under the assumption that changes in the motorcycle ratio will not have a large impact on
the average number of riders per motorcycle or four-wheeled vehicle, we calculated changes in cross-Saturated flow rate

sectional throughput (the number of persons passing through an intersection lane per hour) for various
motorcycle ratios. Note that when performing these calculations we assumed optimal intersection configuration for the motorcycle ratio.
We could ascertain that decreased
pcu/lane/h
6000
motorcycle ratios resulted in a decreased
number of persons passing through inter5000
Motorcycle
sections, and that such reductions were4000
larger with higher motorcycle ratios. The
3000
current motorcycle ratio in Phnom Penh
Four-wheeled vehicle
2000
is approximately 0.7 and that in Bangkok
1000
is approximately 0.3. This indicates that
Phnom Penh in particular will experience
0
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
serious traffic congestion should fourMotorcycle ratio

wheeled vehicles become more popular.
However, this also means that appropriate
traffic operation for the utilization of motorcycles may increase transport capacity.
Figure 3. Changes in intersection capacity due to motorcycle ratio

3. Conclusions
The various analyses performed in this project indicate that motorcycles are a highly space-efficientmeans of transportation. We believe that the development of motorcycle-based taxis and messenger services in Southeast Asia is a result of motorcycles’ mobility making them well suited as a supplementalmeans of small-scale goods distribution and trunk route transport.
Increased demands for transportation result in increased traffic volume. However, trying to accommodate for this volume by focusing on only four-wheeled vehicles will increase private marginal costs (2)and road usage costs. This translates into decreased total social benefit. In contrast, utilization of space-A study on the role and limitations of motorcycles as a means of urban transport in Southeast Asia｜159

efficient motorcycles can decrease private marginal costs, thereby increasing benefit and allowing more
comfortable road usage.
Motorcycle ownership is currently declining in Japan, but intelligent utilization of motorcycles inSoutheast Asian cities may help prevent the worsening of road conditions that accompanies development of automotive societies. However, attaining this utilization will necessitate the solving of many
problems. The over-capacity motorcycle-riding that is frequently seen in Southeast Asia is dangerous,
and there is a need for education to improve driving etiquette. As indicated above, there is also a needfor appropriate road maintenance and traffic control better suited to motorcycle operation. Thus, implementing these changes will require not only traffic engineering and traffic planning, but also urban planning efforts.

4. Future outlook
In Japan, there are numerous studies regarding the utilization of ultra-compact vehicles that are larger
than motorcycles but smaller than small automobiles. How best to position the role of such personalvehicles—including motorcycles—as a part of urban transport, and how to connect them with public
transportation, are important issues not only for Southeast Asian cities but also for cities throughout theworld. In the future, it will be necessary to explore the roles and limitations of such vehicles from a variety of viewpoints regarding environmental and spatial efficiency and traffic safety issues, leading toward
the development of an ideal traffic system.

(2) Private marginal cost: An increased number of automobiles results in congestion and lower traveling speeds. Private marginal cost isa generalized cost referring to the amount of worsened congestion resulting from the increase of a single car (Social marginal cost: Under
these conditions of increased number of automobiles, worsened congestion results in increased costs due to congestion not only to theadded car, but to other cars as well. Social marginal cost refers to this amount of increase).

160｜Practice

Practical application of a public involvementtype system for planning and evaluating roadtraffic safety measures
1. Background and goals
In 1997, the year this project started, about 10,000 people each year died in road traffic accidents inJapan. After the beginning of the twenty-first century, this number significantly decreased, but there arestill an excessive number of road traffic accident-related fatalities. Even though fatality rates have been
cut in half, the present need for further reduction remains unchanged.
Developing increasingly sophisticated road traffic safety measures for further reduction of traffic
accidents will require not only governmental policies, but public involvement as well. This project aims
at constructing public involvement-based road traffic safety policies and evaluation systems, using theseas tools to conduct pilot surveys, and verifying their effects.

2. Research content
This project consists of four pillars, based on which
local governments can reduce road traffic accidents
by half over the medium term:
1. Objective data assessment of road traffic accidents and “hiyarihatto experiences”(1)2. Information exchange among citizens, andbetween citizens and local governments
3. Training and utilization of experts
4. Quantitative evaluation of the effects of roadtraffic safety measures
To put this into practice, we developed a roadtraffic accident reduction system for local governments that utilizes Web-based GIS and the Internet,

Understanding
accident
circumstances

Citizen road users
Postevaluation

Information
disclosure

Needs

Information
provision
Government

Measureimplementation

Supportsystems
Data
Information
gathering collection

Determining
accident factors

Specialized
knowledge
Academics
and experts

Planning
measures

Figure 1. Road traffic accident reduction system
for local governments

and applied this system to the city of Kamagaya,
Chiba Prefecture, as a case model. The system is composed of four subsystems, allowing for implemen-

Project Leader: Hirokazu Akahane
Professor, Department of Architecture and Civil Engineering, Faculty of Engineering, Chiba Institute of Technology(1) “Hiyarihatto experiences”: Named after a Japanese term referring to a close call, hiyarihatto experiences are subjective reports by road
users who experience feelings of fright and danger on roads.

Practical application of a public involvement-type system for planning and evaluating road traffic safety measures｜161

tation of road traffic safety measures according to the PDCA cycle.(2)(1) Road traffic safety measure support subsystem

Utilizing a road traffic accident database as its core, this system allows foradvanced GIS (3) -based aggregation,
searching, and spatial analysis of accident data. Using the hiyarihatto map
creation system, which will be
described in the following section, theroad traffic safety measure support system is capable of integrating accident
data with hiyarihatto experience reports
from road users and district residents.

Hiyarihatto
experience
database

GIS
Map display ofhiyarihatto experience data
Locations with many

Integrated
reported accidents andmanagement of hiyarihatto experience reports
both data types

Map database
Road traffic
accident
database

Map display of road traffic
accident data
Types of accidents at specific locations

Figure 2. GIS integration of data regarding accidents and hiyarihatto
experiences

The system thus allows extraction of locations with road traffic safety problems, making it possible
to organize information in various ways, such as by type of accident and by conditions under which
accidents occur.
(2) Road traffic safety information web-based subsystem

This subsystem is composed of ahiyarihatto map creation system
and a road traffic safety information website. The hiyarihatto map
creation system allows road users
and area residents to participate
via reporting their hiyarihatto
experiences using a website managed by local governments, whichuses this information to generate

Web-accessible
database server• Accident data input• Accident analysis andproposed measures

Internet[Measure support system]
Synchronous server

Traffic engineer

LAN[Hiyarihatto experience reporting system]
Database

Citizens• Hiyarihatto experience
reports• Viewing accident andmeasures informationa hiyarihatto map. The road traffic
Figure 3. Road traffic safety information web-based subsystemsafety information website has
information related to traffic safety policies managed by local governments, and such collection of information from road users and area residents along with information presentation and dissemination by(2) PDCA cycle: A method of continual operational process management performed by repeatedly Planning, Doing, Checking, and Acting.
(3) GIS: Geographic information system. This refers to technologies for comprehensively managing and processing data with associatedpositioning information (spatial data) and presenting that data visually, allowing for advanced analysis and rapid decision making(Source: http://www.gsi.go.jp/GIS/whatisgis.html).

162｜Practice

local governments enables the sharing of traffic safety information between local governments andcitizens.
(3) Road traffic safety measures examination subsystem

This subsystem uses investigation and analysis of locations
extracted from the road traffic
safety measures support subs y s t e m a s c a n d i d at e s f or
installing measures, allowing
for scientific identification of
accident factors and subsequent prioritization of safetymeasures. This mechanism
employs not only traditional
forms of public involvement,such as questionnaires andWorkshopAnalysis and consideration content
Extract locations with manymarked spots and factors
causing accidents(1) Road traffic accidents(2) Questionnaire on
hiyarihatto experiences(3) Traffic volume
investigation(4) Road conditions• Local residents(10 residents’associations)• Elementary and juniorhigh schools (2)(Faculty and PTA)

Provision of expertise
Consideration of safety measures’content

Awareness of issues, evaluation• Clubs for the elderly (1)• City Hall

Experimental implementationof speed humps and roadnarrowers (Pilot survey)• Academics and experts(Kamagaya Police
Department)

Propose comprehensive safety measures(Plan for device deployment)(Consideration of traffic regulation)

4

Figure 4. Framework of road traffic safety system measures in the Higashi-

briefings, but also workshops
hatsutomi district
and pilot surveys that allow
citizens to be directly involved in the examination and implementation of measures.
(4) Road traffic safety measures implementation evaluation subsystem

based on the subsystem’s evaluations. Two forms of evaluation

tion before and after measure
implementation, according to
the aforementioned road traffic
safety measure support and

Evaluation index

Evaluation index value• Influx of throughtraffic into the district• Vehicle speed is too
fast• Location speed• Number of vehicles
passing through• Road users• Awareness of residents
in the area of devices• Ratio of vehicles travelingat 30 km/h or faster• Difference in volume ofthrough traffic• Safety improvements• Measures evaluation

Surveyimplementation

Effects analysis

Measure proposal andimplementation• Installation of speed
humps at intersections• Colored paving at
intersections(Objective) (Subjective)

can be performed: objective
evaluations based on quantitative comparison of the situa-

Accident factors(Objective) (Subjective)

This subsystem evaluates theeffects of implemented traffic
safety measures and provides
feedback, allowing further
improvements to b e made• Location speed survey• License tag survey• Probe investigation• Questionnaire survey• Web-based survey• 26% decrease in the ratioof vehicles traveling at
30 km/h or faster• Through traffic reducedby 14%• 56% recognized speed
decrease• 75% approved of measures

Feedback
Figure 5. Measure effect evaluation subsystem (speed reduction measures)

road traffic safety information
web-based subsystem, and subjective evaluations based on collecting and sorting road user and area resident opinions regarding roadPractical application of a public involvement-type system for planning and evaluating road traffic safety measures｜163

traffic safety measures, according to theroad traffic safety information website.

Speed control measures in the Higashi-hatsutomi district

From 2001 to 2002 in Kamagaya, we initiated a pilot survey and evaluated theeffects regarding measures for intersections with high accident rates, and verified
an approximate 60% reduction in traffic
accidents. Encouraged by these results, in

Speed humps at intersections

2004 we performed a pilot survey on comprehensive safety measures regarding
through-traffic on residential roads in
Kamagaya’s Higashi-hatsutomi 4-chome

Specificmeasures対策内容
Speed
humps at intersections[10 locations]
交差点ハンプ【10 箇所】
Coloredpaving at intersections
locations]
交差点カラー舗装【5[5箇所】

district, which covers an area of approxiFigure 6. Installing speed humps, etc. at intersections
mately 64 ha containing 1,800 households.
(Higashi-hatsutomi district)
Based on information sharing and consensus building at a workshop hosted by local government representatives, the local city hall, and experts,
the district implemented measures such as installing speed humps at ten intersections, resulting in an
approximately 56% accident reduction. Furthermore, the number of reported sudden hiyarihatto experiences and locations fell by 77% and 65%, respectively. Based on these experiences and results in Kamagaya, we created and verified our workflow and developed a training program for users.

3. Conclusions
We have transferred the system from Kamagaya to the neighboring cities of Ichikawa and Shirai, whichhave approximately four times and one half the population of Kamagaya, respectively, with the goal ofclarifying challenges to system construction and operation. This has helped verify the versatility andeffectiveness of the “Kamagaya Scheme.” We have also realized multilingualization of the system throughthe use of Internet-based translation services such as application service providers, and have begun
operation of the system in Penang, Malaysia.

4. Future outlook
Dissemination and continuation of the “Kamagaya Scheme” will require (1) the hosting of seminars foragencies responsible for traffic safety policy implementation, (2) implementing workshops related tosafety technologies and administrative practices for road traffic safety engineers, (3) supporting implementation and operation of the scheme, and (4) supplementing the various databases used in the schemeand promoting sharing between local governments. We believe that doing this will make our system anincreasingly useful tool for countries to collaboratively share experiences and accumulate data relating
to road traffic safety measures.

164｜Practice

Identification of brain regions associated withthe central and peripheral visual field andapplications for improving traffic safety
1. Background and goals
The perception and cognition of pedestrians appearing in the peripheral vision of drivers, and vice versa,
is essential to traffic safety. Therefore, studies of cognitive processing in central and peripheral vision areurgently needed to reduce traffic accidents.
The aim of this study was to make recommendations for the realization of traffic safety by revealing
the visual attributes that play important roles in human cognition and behavior.
1-1. Main study point
Three factors were the focus of this study: elderly individuals, intersections, and night-time.
Elderly individuals:
Intersections:Night-time:

the proportion of elderly individuals in fatal traffic accidents continues toincrease.
according to the study of traffic fatalities by road type, approximately half
the fatalities happen at the time of crossing streets or intersections.
the number of traffic fatalities peaks from dusk on into night-time.

The probability of traffic accidents will increase further when these factors are concurrently
present.
To investigate the correlation between the three factors and human visual function, special attention was paid to peripheral vision, because proper perception and cognition of pedestrians (automobiles) in the peripheral vision by drivers, and vice versa, will definitely improve traffic safety.
The functional properties of peripheral vision in humans have been investigated from the perspective of cognitive psychology but have yet to be fully elucidated. In addition, little information is available
on the central processing of visual information originating in the peripheral visual fields. In this study,
we therefore performed cognitive psychological experiments to investigate dynamic vision and theeffects of aging as well as neurological experiments to quantitate the cortical representation of peripheral
vision using functional magnetic resonance imaging (fMRI). The properties of a wide field of view andtraffic safety were also investigated.

Project Leader: Jinglong Wu
Professor, Graduate School of Natural Science and Technology, Okayama University

Identification of brain regions associated with the central and peripheral visual field and applications for improving traffic safety｜165

2. Research content
2-1. fMRI study on the physiological characteristics of a wide field of viewAfter developing a wide-field stimulus presentation device that operates under the MRI (high magnetic
field) environment, fMRI was performed to reveal functional differences between central and peripheral
vision.
First, retinotopic mapping (functional mapping of the visual cortex)(1)and quantitative analysis of central
and peripheral vision were performed.
Conventionally, it has been possible toexamine only up to 60 degrees ofvisual angle due to the limitations ofBrainMRI撮像領域
area scanned in MRI
MRI session
MRI実験風景

4040度
degrees 8080度
degrees

120120度
degrees

temporal resolution in fMRI. Therefore, to perform this experiment, wedeveloped a new stimulus presentation
Stimulationof central and peripheral vision
中心・周辺視野の刺激
device that enables the mapping of up
Figure 1. Imaging device and technique for cortical representation of
to 120 degrees of visual field. As athe visual field
result, we could confirm that a diffuse
area adjacent to the occipital lobe was the brain region involved in the processing of peripheral vision.
Use of the device, with its wider field of visual stimulation, further revealed that this diffuse area wasmore extensive than previously studies have reported.
Quantitative analysis showed that the size of the brain area involved in information processing
decreases as the visual field nears the far periphery. Furthermore, the study of the temporal frequency
response properties of central and peripheral vision showed that the maximum response was elicited bya temporal stimulation frequency of 4 Hz when the eccentricity was 20 degrees (central visual field) (1)and by temporal frequencies of 4–8 Hz when the eccentricity was 40 degrees (2), but only small differences were observed in the responses to individual frequencies when the eccentricity was 60 degrees(peripheral visual field) (3).
2-2. Cognitive psychological study on the characteristics of wide field of view
A conventional manual device to measure dynamic visual field was automated to quantitatively analyze
the dependency of dynamic visual field on brightness and color. Differences in dynamic visual field
between young and elderly individuals were also measured and analyzed. Further, we modified the light(1) Retinotopy: Using a similar principle as in cameras, light information from an object is projected onto the retina, where it is converted into electrical signals by photoreceptors. In this process, spatial information in the retina is maintained in the visual cortex in thebrain. For example, information from the center of the retina is sent to the posterior of the visual cortex, while more anterior regions of
the visual cortex process information originating from more peripheral locations of the retina. Such reconstruction of spatial information in the retina by the visual cortex is called retinotopy.

166｜Practicesource in the measurement
device, which allowed us to

Measurement of dynamic
visual field

Setting the direction of visual targets
12 longitudinal directions

quantitate the dependency ofdynamic visual field on bright-

135°

45°
30°

150°

ness and color, and to investigate how aging affects the165°

dependency.
Dynamic visual field isdefined as a visual range within

15°
5°

180°

345°

195°
210°

which humans are able todiscriminate a moving object.
Dynamic visual field is particularly important when driving or

120° 115° 90° 75° 60°

330°
315°

225°
240° 255° 270° 285° 300°

Figure 2. Development and use of a dynamic visual fieldmeasurement device

crossing streets. In this study, the Goldmann perimeter was remodeled to be functionally flexible andmore accurate. Underestimation of dynamic visual field by subjects is a serious problem, especially whenstudies involve fast-moving visual targets or elderly individuals with slow reaction speeds. In this study,
we therefore measured the response time of subjects under different condition to correct for thisunderestimation.
Subjects were 5 individuals aged 20–23 years, 9 individuals aged 50–64 years, 4 elderly individuals
aged 65–74 years, and 4 elderly individuals aged 75–80 years. Subjects were instructed to stare at thecenter of the screen and push a button as soon as they notice a target moving inward from the peripheryat a given constant speed. Results indicated that dynamic visual field was relatively wider in younger
individuals than in elderly individuals. With regard to speed dependency, all age groups had a tendency
to decrease slightly as the speed of the target increased. The visual field in elderly individuals aged 75–80
years was approximately half the visual field in individuals in their 20s, revealing a marked effect ofaging. However, dynamic visual field was not lost evenly in an age-dependent manner, and dynamic
visual field instead varied greatly among individuals.
2-3. Investigation of the association between wide field of view and traffic safety
We plan to apply the findings of this study to improve traffic safety and recommend the revision of roadsign installation criteria and of regulation for traffic safety education aimed at elderly people.

Identification of brain regions associated with the central and peripheral visual field and applications for improving traffic safety｜167

Visual characteristics in elderly individuals
and traffic accidents
Peripheral visual informationin traffic environments
Road traffic information
Various hazardous events

Functional limitations in vision
Cortical representation of peripheral vision
Effects of aging on vision
Loss of dynamic vision
Effects of aging on cognitive function
Delay in information processing, action-taking, and related processes

Reduced traffic information from peripheral vision
Ignored traffic laws Delayed risk avoidance

Recommendations toimprove traffic safety■Establishment of senior-friendly traffic
environments■Road designs and automotive equipment parts
that take account of peripheral visual acuity
and cognitive function■Avoiding unseen situations■Making things easily visible■Supporting invisible parts■Traffic safety education of elderly individuals■Incorporation of visual field testing into official
driver’s training sessions

Traffic accident
Figure 3. Recommendations to improve traffic safety based on the relation between visual characteristics
in elderly individuals and traffic accidents

3. Conclusions
Through the investigation of central and peripheral vision in humans, we were able to reveal under whatcircumstances peripheral visual acuity was compromised. The effect of aging on dynamic visual field
was substantial, particularly among elderly individuals aged 75–80 years because of severely impaired
cognition of moving objects in peripheral vision.
In retinotopic mapping, the central information processing area for peripheral vision was narrowcompared with central vision. Furthermore, the study of brain activity in response to temporal frequencies showed that the maximum response was elicited by a temporal stimulation frequency of 4 Hz whenthe eccentricity was 20 degrees (central visual field) (1) and by temporal frequencies of 4–8 Hz when theeccentricity was 40 degrees (2), but only small differences were observed in the responses to individual
frequencies when the eccentricity was 60 degrees (peripheral visual field) (3).

4. Future outlook
When moving on a street (including driving), we sense and process environmental signals before taking
proper actions. To act safely, it is necessary to accurately execute the 3 stages of information processing—perception, cognition, and action—and as the organ that governs these functions, the brain should
be investigated to reduce traffic accidents. In this study, to recommend traffic safety measures, special
attention was paid to intersections and to elderly individuals, who are highly associated with traffic accidents, to investigate the brain function involved in wide-field visual acuity and the effects of aging on
dynamic vision. It is important to continue basic research with emphasis on the central mechanisms
involved in perception, cognition, and action in order to reduce the number of traffic accidents in the
future.

168｜PracticeAn educational program for better control ofemotions while driving
1. Background and goals
Negative emotions such as
irritation, impatience, andanger have been frequently
indicated as causal factors in
accidents in various studies
on human factors. However,this issue tends to be treatedas an inattention error by thedriver or as a legal violation,and is rarely directly taken up
as an educational theme. In
this study, we address thisissue as a topic for driver edu-

Structure of theeducational program
Step 1: Introduction
Step 2: Self-evaluation
Step 3: Understanding stress theory
Step 4: Learning coping strategies
Step 5: Goals

Self-understanding
Enriching individual
resources

90 minutes

Figure 1. Overview of the educational program
cation. The goal of the project
was to develop an educational
program for better control of emotions and examine the effectiveness of the program (Fig. 1).
Emotional control is one of the most important skills required for safe driving and plays a domi-

nant role in other safe driving skills such as vehicle maneuvering and hazard perception according to ahierarchical model of driver behavior. However, it is difficult for a third party to determine what shouldbe learned in an educational program because emotional control skills are highly dependent on individual characteristics. The most important pedagogical point is to help learners understand their own emotional tendencies and to proactively develop emotional control strategies best suited to the individual.
This project aimed at providing opportunities for such learning, by developing an educational programfor improving emotional control skills.

Project Leader: Kazuhisa Ogawa
Professor, Teacher Training Center, Tohoku Institute of Technology

An educational program for better control of emotions while driving｜169

2. Research content
2-1. Methods
The research project consisted of two surveys. The participants in the surveys were 102 professional
drivers (average age 37.38 years) employed by transport and delivery service companies. The first survey
was conducted before and after implementation of the educational program to analyze changes in driving behavior using driving recorders attached to vehicles that the participants operated during daily
work. We also measured changes in participants’ awareness (stress reaction and feelings of self-efficacy)
before and after the program. We also conducted simple interviews one month after the program toinvestigate awareness changes following program participation. The second survey investigated onlychanges in awareness before and after participation in the educational program.
We used three question-

Not very well

Not well at all

DifficultSomewhat difficult

Somewhat easy

Easy

used to identify which parts ofSomewhat welldegree to which the participant
thought the emotion applied
was taken as a measure of stress
reaction (Fig. 2). We also asked
participants to rate whether
they have been able to easily
cope with their emotional state,
and used this as a measure ofself-efficacy.
Questionnaire II was forevaluating the educational program. This questionnaire was

Response B
How easy or difficult is it foryou to cope with thesecircumstances well?

Very wellnaires. Questionnaire I presented examples of emotional
states during driving, and the

Response A
How well do the following
statements describe your feelings
under the given circumstances?

1

Drivers who don’t thank me
when I yield to them are rude.

4

3

2

1

4

3

2

1

2

I suddenly become irritable when
I get caught in traffic when I’m busy.

4

3

2

1

4

3

2

1

3

When I’m trying to make a turn against
oncoming traffic but can’t find an opening,
I get very anxious due to the line of cars
piling up behind me.

4

3

2

1

4

3

2

1

Figure 2. Part of questionnaire I

the program participants founduseful and to get information about their overall impressions regarding the program. We used the resultsof this questionnaire to evaluate acceptance of the educational program.
Questionnaire III was produced based on the Big Five theory(1) and was used to assess the personality traits of the participants.

(1) A recent theory for explaining personality. This theory categorizes the various personality traits into five dimensions: extroversion,
neuroticism, openness to experience, conscientiousness, and agreeableness.

170｜Practice2-2. Results(1) Changes in stress reaction and self-efficacy
We calculated a scalingscore for eight items of

ticipation in the educational program. Higherscores indicate a stronger
stress reaction and stronger

4

Average rating valueior. We converted this toaverage per-item scores andanalyzed changes after par-Average rating value

questionnaire I regarding
anger toward others’ behav-

4

3

2

3

2

Stress reaction
Self-efficacy
1Stress reaction
Self-efficacy
1

Before education After education

Anger at the behavior of others

Before education After education

Impatience due to time pressure

feelings of self-efficacy. As
Figure 3. Changes in stress reaction and self-efficacy following education
shown in Figure 3, stress
reaction was reduced after
program participation and feelings of self-efficacy were improved.
A similar analysis was performed on five items related to feeling rushed under the pressure of time,and rating scores were compared before and after program participation. For impatience, we also foundeffects of reduced stress reaction and increased feelings of self-efficacy after the program.
Analyzing the relation between age and changes in awareness indicated that age in particular was afactor that influenced feelings of impatience after the program. Both young participants (aged 30 years
or younger) and middle-aged participants (aged 31 years or older) indicated reduced stress reaction andimproved feelings of self-efficacy after the program, but the change was greater for the young
participants.
Analysis of the relationship between changes in awareness and personality traits of the participants
indicated no association with stress reaction. Regarding feelings of self-efficacy, however, a significant
interaction was found between feelings of anger and extroversion. We divided participants into twogroups of higher and lower extroversion scores. We found that changes in feelings of self-efficacy werelarger among the participants with higher extroversion scores. In other words, it was suggested that participants who tend to direct mental energy outward found it easier to cope with their anger toward otherroad users after the program.
(2) Participants’ evaluation of the educational program
Questionnaire II contained 17 question items posed as a 4-point Likert scale. Participants evaluated theprogram favorably: Over 80% of participants gave positive responses (“4: Agree” or “3: Somewhat
agree”) for all question items.

An educational program for better control of emotions while driving｜171(3) Changes in driving behavior
No statistically significant changes were found regarding driving behavior of the participants following
the program.

3. Conclusions
Participation in the educational program resulted in reduced stress reaction regarding feelings of anger
and impatience. Such changes in awareness were particularly noticeable among young drivers. Also,
highly extroverted drivers showed particular improvement in feelings of self-efficacy to control anger.
Evaluation of the education program indicated high acceptance overall. However, no definite changes indriving behavior were observed.
In the future, it will be necessary to develop more sensitive measurement indicators for changes indriving behavior. A possible measurement method is to observe specific behaviors such as visual checking and stopping at an intersection when a stressful event occurs on the road. Another problem to besolved is the development of follow-up training to sustain the improvement in emotional control skills.
It is possible that the educational effects found in this study are only temporary changes. Finally, dissemination of this emotional control educational program requires development of a manual. We hope
to develop specific educational measures for organizing and resolving the many psychological problems
that drivers face.

4. Future outlook
In addition to continued verification of the educational effects, instructor training is a major issue
related to dissemination of this educational program. Traditional educational styles in which instructors
attempt to instill knowledge in learners are not suited to deriving self-understanding. In the future, itwill be necessary to plan instructor training workshops that provide learner-oriented instructional
methods such as coaching techniques.

172｜Practice

A study on safety measures considering thepsychological behavior characteristics ofcyclists, from adolescents to the elderly
1. Background and goals
Compared with Western countries, Japan has a higher rate of bicycle accidents. In 2009, bicycle accidents caused 14.1% of traffic fatalities and 17.1% of traffic injuries. Preventing bicycle and pedestrian
accidents has become an essential issue to address for further reducing the rate of traffic accidents in the
future. Regarding bicycle accidents, young people, junior high school students in particular, accounted
for nearly 70% of injuries, while the elderly accounted for 60% of fatalities. There is thus a need for
determining the causes of these accidents and planning measures to prevent them.
This project therefore explores the possibilities for effective educational programs and awarenessactivities targeting cyclists, and gives recommendations for improving bicycle safety, including thoserelated to road environments and social systems.

2. Research content
2-1. Conducting an educational program for junior high school students
In FY 2010 and 2011, we conducted an
educational program at two junior highschools in Suzuka City, Mie Prefecture.
Students participated in voluntary group
work to create hiyarihatto maps,(1) investigate problems, and make specific proposals for improvement plans (Fig. 1).
As a result of these efforts, wefound that students 1) plan routes toavoid major roads and large intersections that invoke psychological feelingsof danger, 2) do not have sufficient space
to walk or cycle due to narrowness of

Figure 1. Example of created traffic hiyarihatto map

Project Leader: Kazumi Renge
Professor, Department of Psychology, Faculty of Psychology, Tezukayama University(1) A hiyarihatto map, named after a Japanese term for a close call, is a map that indicates areas in which participants feel a sense of
danger.

A study on safety measures considering the psychological behavior characteristics of cyclists, from adolescents to the elderly｜173

streets, 3) hold the misunderstanding that the same traffic rules apply to pedestrians and cyclists, and 4)
engage in what subjectively seems to be danger avoidance behavior, but instead puts them in more dangerous circumstances.
There were many cases where students shared problem awareness through actively developing discussions, resulting in specific opinions about what students themselves can do in regard to not only
improving the traffic environment but also performing safety confirmation behaviors that do not rely on
their senses, ensuring proper understanding of bicycle traffic rules, and finding safer routes for commuting to school.
2-2. Survey of bicycle behavior among the elderly and development of education
programs
Previous research has shown that elderly adults who do not have a driver’s license are far more likely to
be involved in accidents than those who do. We conducted a study to elucidate differences in behavior
characteristics between elderly adults with a driver’s license and those without. We performed an investigation of cycling behavior at the Nara driving school in Nara Prefecture on October 4, 2010 and October 17, 2011. The participants were aged 62 to 94 years, comprising 21 individuals who had a driver’s
license and 27 who did not.
Gyro sensors were used to count the number of times participants looked left and right,
and to measure viewing angles and viewing
times. An external camera was also used tocount the number of times participants looked
left and right. A small helmet-mounted camera
was used to monitor running positions (Fig. 2).
Participants walked and cycled through anintersection with poor visibility and throughan experimental course with parked cars.
A general tendency was found in all participants for a lower frequency of safety checks

Figure 2. Gyro sensors mounted on the head and knee

when riding bicycles compared with walking, as was a tendency for riding in the middle of the road.
These tendencies were particularly pronounced in participants who did not have a driver’s license. We
therefore consider it necessary to focus on non-license holders when conducting instruction and training of elderly cyclists.
2-3. Image-based experiment on cycling environment
Bicycles are legally considered to be vehicles and therefore as a rule must travel on streets not sidewalks. However, there has been insufficient investigation of under what conditions cyclists actuallyadhere to this principle. It would be preferable to establish bicycle lanes, but there are many cases where
the road width is insufficient to make that practical. One possible solution is road indicators with bicycle

174｜Practice

You are currently traveling along a road
Road conditions
Lane width

Number of lanes

Automobile traffic

3.5–4.75 m (mid.)2

1–3 cars/min (mid.)

Sidewalk width

Pedestrian traffic

Signage indicating bicycle
traffic allowed on sidewalk

4 m or more (wide)

6 people/h (low)NoneSidewalk conditions

marks(2) to promote road usage by cyclists.
We therefore performed an image-based experiment to grasp the effect of spatial development on theuse of bicycle lanes and road markings from the perspective of both cyclists and automobile drivers (Fig. 3, 4). To
better grasp general trends in bicycling behavior, we performed a preliminary investigation targeting 32 university students in January 2012, and then in March 2012
conducted an Internet-based survey involving 216 participants (aged 20–74 years, 107 men, 109 women).
For the experiment we created static images of avirtual road space under different conditions, showed
participants each image, and asked questions. In the caseof bicycle viewpoints, we asked participants to tell us
where they would ride and their reasons for doing so. In
the case of automobile viewpoints, we presented a bicycle
traveling in front of the automobile, and asked participants where they would pass by it and at what
speed.
Also, knowledge likely has an effect on the decision to ride bicycles on the street or the sidewalk, so
we divided participants into four groups and provided each with varying levels of information regarding
traffic rules, traffic signs, and road indicators, thereby creating differences in knowledge. We also divided
participants according to sex and driver’s license status and investigated the relevance of these factors.
In the image-based experiments from the bicycle viewpoint, 66% of participants said they would
travel on the road if a bicycle lane was present, indicating the effectiveness of bicycle lanes in promoting
road usage. In contrast, the presence of on-road bicycle markings had nearly no effect on preference forroad usage.
Figure 3. Example image of a virtual road spacefrom a bicycle viewpoint

There was an association between participant
knowledge and road use selection, with groups presented with less information indicating a lower prefer-

Situation #11

ence for roads. Regarding sex and the presence orabsence of a driver’s license, male license holders andfemale non-license holders indicated an increased preference for roads.
In the image-based experiments from automobile
viewpoints, the presence of signage for bicycle lanes had
no effect on crossing behavior at large intersections, butbicycle lanes resulted in a trend for increased distance

Figure 4. Example image of a virtual road spacefrom an automobile viewpoint(2) Bicycle marks: Road surface markings placed at regular intervals to indicate where cyclists should ride.

A study on safety measures considering the psychological behavior characteristics of cyclists, from adolescents to the elderly｜175

from the road edge. While the presence of bicycle lanes worsened crossing behavior at smaller intersections by increasing distance from the road edge, the presence of bicycle signage indicated the same trend
as in the case of no signage for riding closer to the road edge.

3. Conclusions
Based on the above results, we provide recommendations as follows.
For young people, there is a need for education and activities that emphasize motivation. We also
consider skill evaluation contests and the use of automotive simulators along with voluntary group work
activities to be important. For the elderly, it is necessary to develop living environments and to devote
substantial efforts toward elderly non-license holders. Finally, it is necessary to improve the cycling environment through the development and operation of bicycle lanes.
It is important that these measures be considered as guidelines for improving cycling safety. While
this project has attempted to take on such issues in a practical manner, there is a need for continued
separate studies toward their implementation.

4. Future outlook
The Road Traffic Act of 2013 calls for stricter enforcement of bicycles traveling on roads near the edge.
To promote both the development of road traffic environments, improved knowledge of the law andsafety among cyclists, and improved driving skills, school-based education and community safety training programs should be implemented nationwide. Such development of cyclist training measures andimprovement of the road traffic environment can likely be further implemented toward safety measures
for automobile and scooter operators in developing countries.

176｜Practice

Addressing issues associated with prehospitalemergency transportation
1. Background and goals
We all take advantage of the 119 emergency ambulance services in the event of unexpected injury or
acute illness. In Tokyo, it takes as much as 6 min 38 sec on average (as of 2012) for an ambulance toarrive on scene after mobilization. Moreover, on-scene time continues to increase every year, potentiallydelaying treatment of high acuity illness, such as cardiovascular diseases and stroke, and causing permanent damage or serious complications. These issues may turn rescue activities that would have saved
lives into fatalities.
Although various factors, including patient- and community-specific factors and changes in social
structures, are involved in prolonging on-scene time, no previous study has examined the entire range
of factors at once, making it difficult to address the problem. Cities that provide broad-based criticalcare activities in densely populated areas, such as the Tokyo and Osaka metropolitan areas, are likely toface problems associated with longer emergency service time, whereas Fukuoka City and other smaller
cities tend to provide critical care activities smoothly within a given area.
The aims of this study are (1) to reveal issues associated with prehospital ambulance transportationby using objective floating car data on ambulance transportation to develop effective measures and (2)to investigate the case where injured or diseased patients are transported from hospital to hospital due
to each one refusing to accept them by comparing differences in emergency care services between cities
with and without such problems. Findings from these studies will allow us to recommend solutions toperforming effective prehospital critical care activities in much broader areas in the future.

2. Research content
2-1. Comparisons of critical care activities among cities of different sizes
To reveal the differences in critical care activities among cities of different sizes, we analyzed actual care
activities provided in Tokyo , Fukuoka City, Fukuoka Prefecture, and Kamagaya City, Chiba Prefecture(Fig. 1). Although the size of Fukuoka City is somewhere between that of Tokyo and Kamagaya City,
individual emergency response teams in Fukuoka City are responsible for a larger population and awider area. Travel time between dispatch and arrival on scene was shortest with Kamagaya City. However, Fukuoka City had the shortest on-scene time, which was 6 min 25 sec shorter than on-scene time
Project Leader: Takashi Moriya
Professor, Emergency Department, Saitama Medical Center, Jichi Medical University

Addressing issues associated with prehospital emergency transportation｜177

Returning to
the station

7’23

Patient handover
to hospital

11’08

6’06

Arrival at
hospital

Transportation

Arrival on scene

Dispatch

Receipt of callFukuoka City

(1’08)

30 min(target time)

13’15

27’11
65’03

Reference: Fukuokashi shobo nenpo heisei 18 nen [Fire-Fighting Annual Report 2006], General Affairs Division, Fukuoka Fire Prevention Bureau

27’06

7’06

Returning to
the station

3’30 13’36

Patient handover
to hospital

Arrival at
hospital

Transportation

Arrival on scene

Dispatch

Receipt of callKamagaya City

(1’35)

16’30

67’48
Emergency activity record collected between November 2004–February 2005, and floating car data collected between November 2004–February 2005

9’39

26’26

Returning to
the station

17’33

Patient handover
to hospital

Arrival at
hospital

Transportation

Arrival on scene

Dispatch

Receipt of call

Tokyo

6’10

18’58

78’45
Reference: Heisei 18 nen kyukyu katsudo no gaiyo [Outlines of Emergency Activities in 2006], Emergency Management Division

Figure 1. Comparisons of current critical care activities provided in Fukuoka City, Kamagaya City, and Tokyo
The target time between dispatch and arrival at hospital is 30 min.

required in Tokyo. Tokyo also had the longest transportation time.
2-2. Current situations in critical care activity provided to high acuity patients duringtransportation
Analysis of emergency care service data collected at the Critical Care Center of Nihon University Itabashi Hospital,(1) Tokyo, revealed that (1) transportation time is excessively long in certain areas, (2)rapid transportation is prevented by narrow streets and railroad crossings where gates remain lowered
for an extended time, and (3) there are only a small number of secondary emergency care facilities
equipped and designated for providing care to moderate acuity patients in Tokyo. This results in patients
having to be transported to tertiary emergency care medical facilities, which provide care to high acuity
patients requiring admission to an intensive care unit, because their conditions deteriorated while the(1) The Critical Care Center of Nihon University Itabashi Hospital is a tertiary emergency care facility for treating patients facing criticalsituations. Patients in less serious condition, but who still require inpatient treatment or emergency surgery, are treated at secondary
emergency care medical facilities.

178｜Practice

The distance between tertiary emergency care medical
facilities is relatively far in Western Tokyo
Transported to Nihon University Itabashi Hospital ispreceded because transportation time is easily predicted

National Defense Medical
College Hospital
Approximately 14.0 km

Western Tokyo

Itabashi Ward

Teikyo University
Hospital

Use of the expressway
is necessary

emergency response teams
were traveling from hospital tohospital in search of an appropriate destination (Fig. 2).

Kita Ward

Approximately 10.5 km

Showa General
Hospital Approximately 8.5 km

KodairaCity

Nerima Ward

Nihon University
Itabashi Hospital

Approximately 8.5 km

Toshima Ward

Railroad crossings and other traffic
factors may affect transportation time

Nakano Ward
Musashino City Approximately 6.5 km
Suginami Ward
Tertiary emergency care

Japanese Red Cross Musashino Hospital

medical facilities

The distance to a tertiary emergency care facility is a straight distance from Shakujii Park, which is located almost mid-way between the Oizumi and Shakujii districts.

Figure 2. Problems associated with the area covered by individual tertiary
emergency care medical facilities

2-3. Example of cities that operate a smooth emergency care system
In contrast, some cities provide efficient emergency care services. For example, Fukuoka City utilizes a
Global Positioning System to locate an emergency response team, which displays the address to shorten
the time to locate the scene,
FAST: a system used to control traffic signals to prioritize an approaching ambulance
utilizes information on trafficand other emergency vehicles and to prevent traffic accidents involving thosevehicles at intersections.
and hospitals’ preparedness to
Development of the standard FAST system
accept emergency patients, andrelocates emergency response
teams if they are unevenly distributed in a given area toreduce travel time, on-scenetime, and transportation time.
Kanazawa City has incorporated a traffic signal preemption system for emergency
vehicles (Fast Emergency Vehicle Preemption System (FAST))
to streamline the city’s emergency services (Fig. 3). In the

Medical institution

Improvement of patient survival rate due to rapid transportation

Optical beaconFiredepartment

Traffic control center

Accident prevention

Preemption of
traffic signals
Traffic signal preemption
to extend green lights or
shorten red lights for
emergency vehicles

Optical beacon
Optical beacon

Scene of the accident
Reference: Shobo no ugoki [Current Developments in Fire and Disaster Management], No. 440, Fire and Disaster Management Agency, November 2007

Figure 3. Fast Emergency Vehicle Preemption Systems (FAST) in
Kanazawa City

areas where the FAST system isin place, the speed of emergency vehicles has been improved, travel and transportation time has beenshortened, and the emergency service area covered by each response team has been expanded.

国際交通安全学会ハン��ックe150213入稿用.indd 178

15.2.17 1:23:35 PM

Addressing issues associated with prehospital emergency transportation｜179

3. Conclusions
A close association between fire departments, on-scene emergency response teams, and hospitals is the
key to proper critical care activities. To improve the rate of life-saving emergency services, it is of paramount importance to shorten and tighten the links between the three divisions in the critical care triangle (Fig. 4). This can be achieved by shortening time for travel, on-scene prehospital care, and transportation. In search of solutions, we investigated the current situations and challenges of critical care
activities provided in three cities.

Arriving
on scene•Deciding route•Continuing observation

Emergency
scene Leaving
scene•Patient handover to hospital;
reporting to physician about
patient’s condition,
prehospital care provided,and observation in ambulance•Submission of a patientdelivery confirmation form

•Deciding route

ion

me

t
rta

spo
tim

lishment of a proper emergency management system or

On-scene timenTra

to locate the scene and toarrive on scene can be effectively shortened by the estab-•Assessment and prehospitalcare by emergency response team
•Determination of a destination
hospital

ivin
g ti

The findings of this study
showed that the time requiredArreby the incorporation of FAST,
and that emergency transport
Dispatch
Arriving
at hospitaltime can be reduced by approFire
Receipt ofLeaving
Arriving at
Return time hospitalemergency
Hospitalfire station
department
call
priately placing regional secPatient handover
Waiting for•Identification of scene emergency call
•Returning to fire station time at hospital
ondary emergency medical•Preparation of
ambulance
facilities. Successful criticalFigure 4. Critical care triangle
care activities cannot be
achieved only by establishing
information systems or by streamlining emergency hospitals. It is important to develop a critical caresystem that is appropriate for the size of each community to build close working relationships and foster
highly sophisticated collaboration between emergency management centers, emergency response teams,
and physicians.
Issues that need to be addressed include the incorporation of the command and control system, theinvestigation of effective wide-based emergency services, and the determination of how the FAST system would improve emergency transportation. Furthermore, it is important to develop measures in theevent of hospitals’ refusal to accept emergency patients in order to improve hospital acceptance rates.

4. Future outlook
The prolongation of time required for emergency care response and transportation is a serious problem
even in local cities. On-scene time is also anticipated to increase due to the expansion of prehospitalcare. It is therefore important to establish an effective multidisciplinary cooperation system between
physicians, nurses, administrators, the police, the fire department, emergency services, and thegovernment.

180｜Practice

Dissemination and promotion of screening forsleep disorders
1. Background and goals
Sleep apnea syndrome (SAS)(1) is a pathological condition characterized by intermittent episodes of loudsnoring and a pause in breathing (i.e., apnea) due to upper airway obstruction by the tongue sliding into
the back of the throat. This results in shallow sleep and insufficient oxygen supply to the brain, so individuals with SAS are unable to obtain sufficient sleep, experience excessive daytime sleepiness, and easily fall asleep, resulting in low concentration and a high incidence of accidents due to careless driving
and falling asleep at the wheel.
Several million people are estimated to have SAS in Japan. Even though continuous positive airway
pressure (CPAP)(2) therapy has been established to treat SAS, only about 300,000 patients are currently
treated by CPAP. This is in part because sleepiness due to SAS can be easily mistaken as an age-related
chronic fatigue symptom, and also because many individuals with SAS do not readily feel sleepy after
living with chronic sleep loss for years and therefore do not consult a physician, leaving SAS untreated.
Against this background, a first step would be to establish a system to screen individuals with SAS who
require further treatment. However, it is impossible to impose the burden of comprehensive testing on
every person who is suspected of having SAS because a definitive diagnosis of SAS requires elaborate
and costly overnight testing at a specialized medical facility. For this reason, a simple screening system isrequired to narrow down those individuals who need comprehensive testing. This study aims to develop
and disseminate an SAS screening test and promote the treatment of SAS.

2. Research content
2-1. Special seminar on sleep-disordered breathing
In 2012, at the Nara Trucking Association, the International Association of Traffic and Safety Sciences
hosted a special seminar entitled “Sleep-Disordered Breathing and Health Problems among Truck Drivers” and provided comprehensive information about SAS to trucking business owners, health

Project Leader: Takeshi Tanigawa
Professor, Department of Public Health, Graduate School of Medicine, Juntendo University(1) Sleep apnea syndrome (SAS): a disease characterized by episodes of apnea during sleep. Apnea is defined as a pause in breathing thatlasts more than 10 seconds. SAS is diagnosed when apnea occurs more than 5 times in 1 hour or 30 times in 7 hours during sleep.
(2) Continuous positive airway pressure (CPAP): a method used to prevent airway obstruction by sending pressurized air (positive airway pressure) via a tube to a mask worn on the nose in order to compress the soft tissues surrounding the root of the tongue and thereby
open the airway.

Dissemination and promotion of screening for sleep disorders｜181

100.0%

100.0%

90.0%

90.0%

23.0%

80.0%
70.0%
60.0%
50.0%

77.0%

40.0%
30.0%

80.0%

All subjects (100%)
responded with“useful” !

60.0%

Change in awareness of
SAS was reported by
96.4% of the subjects.

50.0%
40.0%

60.0%

30.0%

20.0%

20.0%

10.0%

10.0%

0.0%

36.4%

70.0%

0.0%

Very usefulSomewhat useful

Was there any change in your awareness of SAS?
A lot

Figure 1. Impact of the special seminar

A little

Figure 2. Change in awareness of sleep apnea
syndrome

supervisors, and truck drivers. A survey conducted after the meeting revealed that the meeting was an
excellent learning experience for the attendees (Figs. 1, 2).
2-2. Administration of a screening test
After the seminar, attendees were recruited for an SAS
screening test, and the openings for 200 test subjects werefilled in just 3 days, revealing high levels of interest in SAS
among meeting attendees.
In this study, a flow sensor, used as a simple tool tomonitor breathing and screen for SAS, was mounted overthe nose and mouth to examine for apnea and hypopnea
during sleep based on the degree and frequency of changes
in air flow (Fig. 3). The notable feature of this testing is thatSAS screening can be performed at home using a small takehome device with a little burden on the subject.

Figure 3. Simple diagnosis with a flow
sensorIn addition to the use of a flow sensor, a self-administered questionnaire survey was performed in order to look for a correlation between SAS and perceived
sleep quality. This questionnaire is the Japanese version of the Sleep Disorders Screening Survey used at
Harvard University in the United States and employs the Epworth Sleepiness Scale as a measure of daytime sleepiness and also asks about subjects’ sleep and driving patterns.
2-3. Results(1) Subjects
The survey results showed that 48 subjects (24%) were living with moderate to severe sleep-disorderedbreathing. The severity of respiratory disturbance was positively correlated with the degree of obesity
but not with other factors, such as age, smoking or drinking habits, blood pressure, and neckcircumference.

182｜Practice(2) Association between subjects’ experiences and sleep-disordered breathing
Many subjects with a high respiratory disturbance index had suspected in the back of their mind thatthey had SAS or narcolepsy. Moreover, a relatively large number of subjects had been informed about
their apnea or snoring even by someone who was in the next room. Respiratory disturbance index was
not significantly correlated with the sleepiness scale score.
(3) Sleepiness and severe sleep-disordered breathing
The findings of this study revealed that more than 90% of the subjects with sleep-disordered breathing
did not actually experience intense daytime sleepiness.
2-4. Comprehensive testing
Diagnostic criteria for SAS are based on polysomnography (PSG) (3) testing. PSG evaluates
the quality and amount of sleep by using

PSG involves electroencephalography as the major component,
electrooculography, electrocardiography, and the measurements of breathing
patterns, peripheral blood oxygen saturation, and body posture. PSG requires
a special examination room, a technician trained in PSG, and skills in data
recording and analysis.

numerous sensors and electrodes to measure air
flow in the nose and mouth, snoring, arterial
oxygen saturation, breathing motion in thechest and abdomen, and posture (Fig. 4). A special examination room and a technician trainedin PSG are needed to conduct PSG, and therefore, it is not only costly but also time-consumFigure 4. Overnight PSG: a time-consuming and costly
definitive diagnostic method for SAS
ing and a large burden on patients.
Although 13 subjects were suspected ofhaving severe SAS according to the screening test
SAS screening of 200 subjects
conducted by the Nara Trucking Association, only 2of them subsequently underwent PSG (Fig. 5). Thisoutcome stands in sharp contrast to the high levels ofinterest in SAS shown by the subjects prior to thescreening test, most likely reflecting the large burden
imposed by PSG.

3. Conclusion
In this study, a special seminar was offered to trucking business owners, health supervisors, and truck
drivers affiliated with the Nara Trucking Association,

Screening test results
2 subjects (1%)
Grade A:
26 subjects (13%)
Grade B:
76 subjects (38%)
Grade C:
35 subjects (18%)
Grade D:

Grade E:

Unable to grade:
Cancellation:

13 subjects (6.5%)
40 subjects (20%)
8 subjects (4%)

Outpatient Sleep Clinic, Tenri Municipal Medical Center
Number of contacts:
4 subjects (2%)
Appointment for PSG:
2 subjects (1%)
PSG performed:
2 subjects (1%)

Figure 5. Approach taken by the Nara Trucking
Association(3) Overnight polysomnography (PSG): an overnight screening test performed on admission to a special examination room to examine
sleep patterns by using electroencephalography, electrooculography, and electromyography of the mentalis, as well as breathing patterns
by collecting data on airflow through the mouth and nose and the movement of the chest and abdomen. PSG is used to determine theseverity of SAS and the appropriate treatment.

Dissemination and promotion of screening for sleep disorders｜183

followed by a questionnaire survey and screening test administered to approximately 200 truck drivers.
In this way, we attempted to establish a system with the following flow: awareness-raising about SAS
screening → screening test → comprehensive examination and treatment.
With regard to the correlation between sleep-disordered breathing and daytime sleepiness, morethan 90% of the present subjects with moderate to severe sleep-disordered breathing answered that they
did not experience daytime sleepiness. This clearly indicates that subjective tests are not enough toscreen for SAS, and therefore, more objective screening tests, such as the flow sensor method, are needed
to detect individuals with undiagnosed SAS. This study also suggests that society as a whole needs to beaware of SAS because some aspects of the disease cannot be addressed by individuals who have SAS.

4. Future outlook
The awareness-raising activity presented in this study is an example that can be applied to any region
across Japan. Our goals are to develop and disseminate an effective SAS screening system and to reduce
the number of traffic accidents via the promotion of early detection and early treatment of sleep-disordered breathing. In collaboration with the relevant administrative agencies, we will also recommend
approaches for the early detection of sleep disorders for which awareness among drivers is low.

184｜Practice

Creating installation guidelines for tactile
ground surface indicators (braille blocks) for thevisually impaired
1. Background and goals
Tactile ground surface indicators for the visually impaired, also known as braille blocks, were invented
in Japan in 1965. Since then, braille blocks have been installed not just in Japan but throughout theworld. It is gratifying to see the growing number of installations, but because they have spread without
clear installation guidelines and methods in place, there are currently a number of installations aroundthe world that are dangerous, pose barriers to other pedestrians, or do not serve their intended function.
Another problem is that braille blocks are being manufactured according to the unique rules of various
regions, so there is a lack of design uniformity. There are even cases within Japan where specific areas
are installing blocks according to local rules. This situation has made clear the necessity of establishinginstallation guidelines that can be used both in Japan and overseas for braille blocks to be utilized byvisually impaired persons. The goal of this project is to elucidate problems related to the installation of
braille blocks currently in use, prior to the establishment of such guidelines.
Braille blocks (formally, tactile ground surface
点字ブロック（正式名称：視覚障害者誘導用ブロック）
indicators for visually impaired persons)

Directional block
Indicates the direction in whichusers can move.
Warning block
Indicates locations where careshould be taken. Examples
include before crosswalks, stairs,
branch points, guidance plates,and obstacles.

London, UK

Brussels, Belgium

Figure 1. A directional block anda warning block
Kuala Lumpur, Malaysia

San Francisco, USA

Figure 2. Dissimilar braille blocks

Project Leader: Katsumi Tokuda
Professor, Faculty of Medicine, University of Tsukuba

Creating installation guidelines for tactile ground surface indicators (braille blocks) for the visually impaired｜185

2. Research content
Evaluation experiments were performed with visually impaired participants who are the intended users
of braille blocks, and areas needing improvement were summarized. Questionnaires and interviews werealso conducted to investigate the impact of braille blocks on other pedestrians (in particular wheelchairusers, the elderly, stroller users, young children, etc.) and to elucidate needed improvements.
2-1. Evaluation experiments with visually impaired participants

Example of an overly narrow warning block(Nagasaki City)
Example where no warning block has
been installed at a crosswalk entrance(Sapporo City)

Example where no warning block is installed at anintersection of directional blocks (Saga City)

Example of erroneous installation
positioning (Nisshin City, Aichi
Prefecture)

Example where no warning block is
installed at an intersection of
directional blocks (Toyama City)

Figure 3. Inappropriate placements of warning blocks

The evaluation experiments with visually impaired participants were conducted in order to investigate
the matters that only users can evaluate, such as the placement of warning blocks before obstructions,the angle of warning blocks placed before changes in the direction of continuous directional blocks,
dangers posed by blocks and rules used in only certain locales, and the necessity of installing directional
blocks that indicate directions in front of intersections. Most experiments were performed using temporary braille block installations on the University of Tsukuba campus, but in some special cases experiments were performed at actual installation sites.
The following results were obtained. (1) Warning blocks should be installed in cases where thedirection of directional blocks will bend with an interior angle of 135° or less. (2) Ministry of Land,
Infrastructure, Transport and Tourism guidelines specifying that warning blocks should be installed 30

186｜Practice

cm in front of potential hazards are appropriate. (3) Some blocks used in accordance with local rules areincapable of providing appropriate warnings. In particular, situations where warning blocks conforming
to JIS standards are mixed with directional blocks conforming to local rules are extremely dangerous,
and urgently require improvement.
2-2. Braille blocks as a barrier to wheelchair users and other pedestrians
Interviews and questionnaires were conducted with pedestrians for whom braille blocks may pose a barrier, such as wheelchair users, the elderly, stroller users, and those with small children.
In a survey of wheelchair users, 72% responded that they regard braille blocks as a barrier. In a survey of walking aid users, 85% reported that it is difficult to pass over braille blocks. One respondent
reported trying to avoid braille blocks as much as possible, but in some locations, tiles are so pervasivethat they are impossible to avoid.
Most stroller users (82%) reported the stroller getting caught up on braille blocks. There were also
reports that the vibrations caused by passing over braille blocks are strong enough to wake a sleeping
child. In a survey of guardians of small children, 50% reported cases of children stumbling and tripping
over braille blocks. One respondent reported a case where a two-year-old child tripped on braille blocks,
resulting in a large bump on the child’s head.
The above indicates the necessity of methods for installing braille blocks that do not pose a barrier
to other pedestrians.

3. Conclusions
On the basis of the results presented above, we have created Japanese and international editions of the
Guidebook for the Proper Installation of Tactile Ground Surface Indicators (Braille Blocks): Common
Installation Errors as a supplement to the installation guidelines from the Ministry of Land, Infrastructure, Transport and Tourism. We have also held information sessions at approximately 40 domestic
institutions and facilities, as well as 15 overseas institutions.
In the future, we will more widely distribute the guidebook that we created, along with additional
explanations as necessary. We hope to continue working toward further optimization of braille blocks,
both in Japan and abroad.

Creating installation guidelines for tactile ground surface indicators (braille blocks) for the visually impaired｜187

Installation rules for directional blocks• Directional blocks should be installed in locations where there are no potential hazards within
30 cm to the sides or overhead.
• Directional blocks should allow for easy recognition of indicated movement directions.
• Directional blocks should guide users to necessary locations.
• Directional blocks should maintain continuity.
• Warning blocks should not be installed before bends with an interior angle of 135° or more.
• Tiles should be of sufficient surface area to allow tactile recognition through shoe soles.

Installation rules for warning blocks• Warning blocks should be installed in locations sufficient to allow users to stop before obstructions (30 cm in front of obstructions)• Warning blocks should clearly indicate path branches.
• Warning blocks should allow easy recognition of the meaning of the warning.
• Tiles should be of sufficient surface area to allow tactile recognition through shoe soles.

An example of an installation improvement given in the guidebook
Directional blocks must maintain continuity. Manholes are a common reason for interrupting
the continuity of directional blocks. In such situations, directional blocks should also be installed
on top of the manhole.
[An example of an installation improvement]

4. Future outlook
As of April 2014, we have completed field investigations in 101 countries and regions. Braille blocks
have been installed in many countries and regions, but we identified many errors in those installations.
We have presented this information through reports and oral presentations at various international conferences. We have also responded to requests for advice regarding braille block installations in several
countries, including Turkey and Israel. In the future, we hope to make whatever efforts we can toward
worldwide unification of installation methods for braille blocks. Our book Tenji burokku [Braille blocks],
which is based on the results of our activities at the IATSS and follow-up research, won the 2013 Mitsui
Sumitomo Insurance Welfare Foundation Award.

188｜PracticeEnsuring urban public transportation mobility
for people with intellectual disabilities
1. Background and goals
As of the end of 2006 there were around 550,000 persons diagnosed with intellectual disabilities inJapan, accounting for approximately 0.4% of the population.
The Law for Buildings Accessible to and Usable by the Elderly and Physically Disabled Person andthe earlier version of the Transportation Barrier-Free Law were combined into the Law for Promoting
Easy Mobility for the Aged and the Disabled Person, which went into effect in December 2006.
Due to these policies, various handbooks and guidelines related to human response and facilities
development have been published, but in many cases these resources remain unknown to transportation
operators in the field. This has led to insufficient addressing of issues related to persons with intellectual
disabilities.
Against such a background, this project was formed and research began in 2011 with the goal of
examining policies related to international trends in ensuring mobility for persons with intellectual disabilities, and thereby uncovering issues needing to be addressed in Japan.

2. Research content
2-1. International case study 1: SITES (Curitiba, Brazil)
The SITES handicapped student bus system, started in Curitiba, Brazil in 1983, uses standard buses
incorporated into an established transit
system. In that system, buses from various
locations in the city arrive at a connecting terminal in the northeast downtown≪The SITES system≫

Students with a variety ofdisabilities board bus
Students attending
the same school

area at a time. Students board buses at thestop closest to their home and head forthe connecting terminal. Students from

SITES
Terminal
School

all schools use the buses and students
with a variety of handicaps share the same
system. At the connecting terminal, they
can change to buses heading for their

SchoolChanging buses from home to busesheading to school

Figure 1. The SITES system

Project Leader: Fumihiko Nakamura
Professor and Dean, Institute of Urban Innovation, Yokohama National University

Ensuring urban public transportation mobility for people with intellectual disabilities｜189

individual schools.
Interviews were conducted with intellectually disabled students changing buses at the SITES terminal, as well as personnel, such as bus drivers and accompanying guides. This resulted in new findings,
including that there was little trouble related to changing buses and that the system presented a platform
for exchange that leads to increased sociability in participants.
2-2. International case study 2: The MogLi project (Germany)
MogLi is a research project supported by theGerman Federal Ministry of Education andResearch related to mobility for the intellectually handicapped. The project targets special
needs schools in the town of Nordhorn andtheir students. The project began an experimental attempt to utilize chartered buses forstudents, in which bus operators and local
police serve as guides. After verification experiments were complete, the system was put into
place, and guided busing is now performed ona regular basis.

Figure 2. Explaining how to ride the bus to school

2-3. Domestic experiment 1: Stop mark display experimentInstalling stop marks for students is ineffective without accompanying education regarding the meaningof those signs; unknowing students will simply pass by without heeding them. We therefore performed
an experiment in which student-oriented stop marks were installed in the vicinity of target schools forthree months, and during a field trip, the meaning of the signs were explained to students. This experiment had two goals: elucidating the effect of pre-education including field trip-based class instruction
regarding stop marks to students at special needs schools, as well as finding issues related to class
instruction on stop marks.
The experiment targeted elementary and junior high students
who commute by school bus, not high school students who wereable to travel to school on their own.
We were able to see results in post-interviews with school personnel, but for only a few months after the experiment, and thus
were not able to observe improvement of students’ understanding
beyond that. However, we expect that continued education will
result in students’ increased learning of traffic rules.

Figure 3. A stop mark2-4. Domestic experiment 2: Commuting to school by city bus
With the goal of elucidating the effects of educating city bus guidance involving transportation operators

190｜Practiceand issues related to performing such education, on January 10, 2013 we performed an experiment withthe cooperation of the Seya Yogo School (Yogo being a Japanese term used in special needs education) in
Yokohama, Kanagawa Prefecture, related to bus guidance that targeted students at that school. The contents of instruction are shown in Table 1.
Table 1. Contents of instruction regarding city buses

Item

Method in the experiment

Safety inExternal
Getting on and off the bus
safetyManners

Explanation of blind spots
Lining up at the bus stop
Reading destination displays(destination, route number)
Reading in-bus electronic displays(stop name)Showing dangerous spots at an actual bus stop
Lining up before actually boarding the bus
Creating a destination (route number) game to explain which busesshould not be ridden

Description of the stop button

Verbal description (including when to press), followed by one student
pressing button
Explanation of bus passes and prepaid cards, experience showing bus
passes to driver, and using card reader for prepaid cards
Verbal cautioning
Verbal cautioning to hold on to handrails and straps
Verbal cautioning; actually performing getting on the bus in turn
University student volunteers perform the role of injured persons.
University student volunteers perform the role of general passenger;
describe sitting in an empty seat

How to show tickets and bus passes
When to stand up
Points to follow while standing in the bus
Taking turns getting on the bus
Explanation of priority seating
How to sit (when someone else isalready sitting)
Not making noise, not running

Verbal description while watching the board display

Verbal cautioning

Interviews conducted after the experiment indicated that students hearing explanations by uniformed bus drivers or transportation operators had a greater impact than did those delivered by educators or guardians, allowing listeners to better retain the presented information and to recall it when conducting busing guidance.
2-5. Domestic experiment 3: Commuting to school by automated guided transit
It is possible that students who are able to travel to school on their own via public transportation also
use automated guided transit. We therefore conducted a similar experiment to examine whether students at a domestic special needs school could commute to school via line A on one such automatedmetro. The experiment was conducted on February 19, 2013 with 26 student participants. The contents
of instruction are shown in Table 2.
In post-interviews conducted with Yogo school educators, the following comments were noted:• The difficulty level was low, since students are already able to get to school by themselves. For
other students who are not able to get to school by themselves; however, experiential demonstrations would likely be required over verbal explanations.
• Students would likely better understand explanations given in stopped cars or in the station,rather than on moving cars.

Ensuring urban public transportation mobility for people with intellectual disabilities｜191

Table 2. Contents of instruction regarding automated metro
Outside Getting on In-car
safetyand off safety

Item

Explanation and teaching methods

Cautions about platform doors

Verbal cautioning about running to board cars, getting caught in doors, etc.

Manners

Verifying arrival time
Verbal confirmation of which station different lines are heading for
Explanation and confirmation of prepaid card reader locations
Verbal instruction to give depleted prepaid cards to parents and teachers(How to use ticket vending machines)
to be recharged
Points to follow when standing from seats Verbal cautioning
Points to follow while standing in the car Verbal caution to hold on to handrails and straps
Verbal cautioning; actually performing getting on the car in turn
Taking turns getting on the car
Verbal cautioning to not make noise, and to not run; verification of waiting in line.
Waiting on the platform
University student volunteers perform the role of injured person
Description of priority seating
University student volunteers perform the role of general passenger; describe
How to sit(when someone else is already sitting) sitting in an empty seat
Verbal cautioning to not make noise, not run
How to spend time in the car

Reading electronic displays
Description of arrival platforms
Passing through ticket gates

Other

Handling emergencies

Description of the intercom call, confirmation of the location of station staff

3. Conclusions
This project addressed issues in commuting to special needs schools by examining case studies overseas
and by performing verification experiments in Japan based on those overseas findings.
Working to further support the mobility of intellectually handicapped persons in the future will
not be possible without the support of not only schools, but also transportation operators, road management personnel, and transportation managers. A future topic is therefore the awareness building activities and the development of systems for promoting common understanding among transportation
officials.

4. Future outlook
We hope that the results of this research lead to deeper communications between schools for students
with intellectual disabilities throughout Japan and area transportation operators, the further expansionof various verification experiments, and furthered accumulation of knowledge.

192｜Practice

A study on the level of service for local public
transport to secure basic daily life
1. Background and objective
Maintaining public transport services is not an easy task for local community, especially in rural areas.
Residents who are unable to use private cars feel difficulty in taking opportunities for the minimum
activities necessary for daily life, such as commuting to work or school, visiting shops, and going to thehospital. Faced with financial constraints, a question of where and to what extent public transport services should be secured and maintained is a significant concern for those responsible for local transport
policy.
To determine the level of service for public transport that should be secured, it is necessary todefine an ideal state of the local community and clarify the role of transport to achieve it. However, nosufficient methodology to this end has been established.
Accordingly, this project was implemented to create a method for determining the level of service
for public transport that a local community should secure and to develop a methodology by which toformulate a local public transport plan as the basis of these services.

2. Methodology and field study
2-1. Significance of local public transport planning and necessity of planning
methodology
The number of users of public transport has decreased along with the progress of motorization, andpublic bus services are no longer profitable in regions where car usage has become widespread. The factthat services essential to society are not sufficiently provided when left to private businesses suggeststhat local public transport should be regarded as social infrastructure.
What changes when securing and maintaining local public transport are treated as improvementsof social infrastructure? The change is the resulting necessity of planning. For example, planning is
implemented when developing social infrastructure, such as river and road improvements. The reason
for implementing this planning is to demonstrate that the scheduled improvement will be efficient andeffective, and to build social consensus, because the improvement of social infrastructure will be carriedout by a public entity and funded by taxes. In other words, this is planning with a public intent. However, while there are business plans for local public transport decided by companies, almost no transport
Project Leader: Hideyuki Kita
Professor, Division of Civil Engineering, Graduate School of Engineering, Kobe University

A study on the level of service for local public transport to secure basic daily life｜193

plans are decided as social infrastructure improvement plans. One possible reason for this is a lack ofplanning methodology. Herein lies the significance of constructing a planning methodology by which toestablish the level of service for local public transport in this project.
2-2. Framework
When determining the level of service for public transport, the level that should be secured cannot be
decided unilaterally. Stipulations such as operating a certain minimum number of buses per day are notmeaningful per se. Instead, the basic index is the amount of opportunities for activities that can be
secured via the operating buses. Furthermore, in the event that the municipality improves the public
transport service, the improvements need to be based on the decision of residents as both taxpayers andusers of public transport. The budget constraints of the municipality are limited according to the tax
burden of the residents, and so the administration should determine the kind of public services that arenecessary and the level of increase in tax burden that residents would permit in return, reflecting this in
the budget. In this project, we established a review framework for the local public transport plan asshown in Fig. 1, recognizing the importance of the idea that residents select the combination of opportunities for activities to be secured and the associated tax burden.

Users
Opportunities for daily life activities
Activity times
Quality of opportunities for activities

Non-users

Provider (municipality/business)
Review of alternative plans• Route plans• Timetables• Vehicles/service format, etc.

Inherent value, potential
value of use, etc.

Amount of willingness to pay

Selection

Menu of services and burdens

Figure 1. Review framework for the local public transport plan

2-3. Planning methodology for local
public transport

Local public transport master plan

(1) Overall structure
Local public transport planning is the selec-

Local public transport plan decision-making processtion and proposal of the most desirable public
transport system for the region. To this end,

Local public transport plan content structure

three stages are necessary: (1) demonstrate the

Figure 2. Overall structure of the local public transport plan

194｜Practice

way of thinking by which the desired public
transport system is selected, (2) select adesired public transport system, and (3) present the outcome of the selection. In this project, we proposed a planning system comprising the three elements shown in Fig. 2.
(2) Local public transport master plan
The local public transport master plan is thedeclaration of the intent to create a local public transport plan. Table 1 shows the necessityof planning and shows the stance of themunicipality formulating and promoting theplan as policy.
(3) Decision-making process and structureof local public transport plan content
The process for deciding the local public
transport plan is systematically organized sothat all details that must be considered to formulate a better plan are presented. Here, it isnecessary to list proposals for consideration in
full and have the local residents select the best
proposal according to the relationshipbetween the benefit returned and the tax burden. The organization of the content of thelocal public transport plan (Table 2) presents a
structure for when the results of the investigation carried out based on the decision-making
process and the service provision plan selected
are summarized as a local public transport
plan. We therefore consider this to illustrate
one of the standard forms of the local public
transport plan.

Table 1. Local public transport master plan
1. Identification of the structure of exchanges among people in
the local community
2. Image of a mobility plan for the people in the local
community
3. Basic policy for securing public transport
4. Public body's declaration to promote public transport policy
5. Policy for the effective administration of public transport
services
6. Appeal for the mobilization (cooperation) of local residents
7. Basic stance toward local public transport planning
Table 2. Structure of public transport plan content
1. Background to the plan
2. Verification of the local public transport master plan
3. Decision and zoning of service provision standards
3.1 Framework of the plan
3.2 Local characteristics
3.3 Structure of the region and basic structure of the public
transport network
3.4 Opportunities for activities that should be secured
3.5 Service provision standards for each zone
4. Service provision plan
4.1 Transport services
4.2 Form of services
4.3 Route network plan
4.4 Region-specific service plans
4.5 Fare/local tax burden
4.6 Service costs/improvement of efficiency
5. Public procurement plan
5.1 Estimation and classification of profitable/unprofitable
routes
5.2 Selection of administration format
5.3 Selection of transport operator
6. Public commitment

2-4. Field study
To verify whether the planning methodology proposed in this project is effective and suitable for practical application, and to identify issues and points for improvement, a field study was carried out in
Hirakawa City, Aomori Prefecture. The research group provided expertise and gave technical advice to a

A study on the level of service for local public transport to secure basic daily life｜195

local colloquium, and the region offered progress and investigation results to the research group. At thecolloquium, alternative plans were presented for the number of buses and the timetables necessary fordaily life, the number of services operable within the limits of the subsidy, and the resulting passenger
fares. A discussion was then held among the residents, who elected for a combination of a 200 yen fareand an increased number of services in comparison to the present 100 yen fare and 5 services. They
went on to propose the scheduling of school buses and other such development.
In this way, the residents themselves were able to select the public transport services to provide
opportunities for activities, confirming that the review framework was applicable, at least in this context.
From the achievement of more favorable conditions for the residents than before and the greater abilityof the municipality to provide public transport that meets the needs of the residents within the limits offinancial constraints, the effectiveness of the review framework was also confirmed.

3. Conclusions
In the event of the municipality participating in the provision of public transport services, the municipality cannot unilaterally determine the level of service that should be secured, and it is only possible toselect the level of service by deciding a local transport plan. Through research, we proposed the construction of a methodology for local public transport planning and a method for selecting the level ofservice. It was then confirmed that these were effective and suitable for application in practice. Based onthese results, the research team is compiling guidelines for local public transport planning.
After the Act on Revitalization and Rehabilitation of Local Public Transport Systems was enactedin October 2007, many municipalities began formulating public transport plans. Future tasks are
improving the methodology proposed in this project through implementation and applying it broadly. It
may also be necessary to go beyond the provision of public transport, and to consider a comprehensive
support strategy that incorporates the policies of various administrative departments.

196｜Practice

Traffic safety and traffic enforcement

1. Background and goals
In 2012, the number of traffic accidents in Japan decreased for the eighth consecutive year to around
660,000. These accidents resulted in 4,411 fatalities, a reduction to approximately 30% of the peak in
1970. Although the downward trend in injuries continues, this year there have already been 820,000
people involved in traffic accidents, so accident prevention remains a significant problem. In particular,
there is a need for further efforts to eradicate fatal accidents due to drunk driving.
In the past, traffic enforcement efforts have had some level of success in preventing traffic accidents.
However, there seems to be no end to drivers who do not obey traffic rules. Cracking down on traffic
violations and strengthening penalties can resort in a short-term reduction of traffic accidents, but theytend to return to their previous levels with the passage of time.
This study aims to provide a quantitative measure of the effect of traffic enforcement on reducing
traffic accidents, and examines possible measures.
1-1. Research viewpoint and method
The embodiment of traffic enforcement has regional characteristics. For example, in large metropolitan
areas there are often efforts to control parking violations and vehicle access violations, both of whichmost frequently occur in densely populated areas. By contrast, in less densely populated rural areas,
efforts tend to be directed toward speed limit enforcement. There are also seasonal variations, such as
speed limit enforcement being more concentrated during the summer in regions that receive heavy
snow in winter. We therefore performed an analysis from the viewpoint of the regional characteristics ofviolators and violation enforcement.

2. Research content
2-1. Relation between traffic enforcement and traffic accidents
This section discusses whether traffic enforcement is effective in reducing traffic accidents. To give an
example, a relational diagram is presented showing the number of traffic enforcement incidents per day
and the number of traffic accidents per 1 million population in Tochigi Prefecture (Fig. 1). There werevery few traffic enforcement incidents (e.g., 100 incidents per day or less) on days such as the New Year’s
Project Leader: Akinori Morimoto
Professor, Faculty of Science and Engineering, Waseda University

Traffic safety and traffic enforcement｜197

Number of traffic accidents (accidents/day)holidays when little traffic was on
the roads, and there were few traffic accidents on such days. Becauseof the existence of such atypicaldays, simply determining the correl at ion co ef f icient b et we en
enforcement and accidents would
likely not give a clear relation.
However, we also found atendency for the maximal numberof traffic accidents to decrease as

Average number of traffic incidents per day: 408
Average number of traffic accidents per day: 52

90

Decreased upper bound (95th percentile)

80
70
60

Average value

50
40
30

0

100

200

300

400

500

600

700

800

900

1000

1100

Number of traffic incidents per 1 million population (incidents/day)Figure 1. Relation between number of traffic enforcement incidents
and number of accidents in Tochigi Prefecture

the number traffic enforcement
incidents increases. The relational

diagram clearly shows that the upper bound (95th percentile) on the number of traffic accidents is
reduced as the number of traffic enforcement incidents increases. This tendency was the same in Okinawa Prefecture and Akita Prefecture. These results suggest that traffic enforcement has the effect of
decreasing the number of frequent traffic accidents.
2-2. Violation history of first parties in traffic accidents
Next, the focus is turned to first parties in traffic accidents—the pedestrian or driver of the vehicle whobear the greatest responsibility for the accident—and the first party’s history of past violations is
considered.
Figure 2 shows of the
Number of violations
2
5
6 or more
4
1
3(%)
types of traffic violations for25
which the first parties in acciApproximately 23% of first parties in accidents had at least
dents occurring in 2009 were20
one violations for speeding in the previous five years
cited during the five-year period15

2004–2009. The violation histories show that 64% of male and
45% of female first parties had

105

some type of traffic violation on
se

ob
ile

Dr

ph
on
eu

ing

ed
ar
ea
ict

es
tr

un
kd
riv

M

on

ivi
ng

Dr

No
nu

e-

Sp
ee
din
g
se
of
se
at
be
lts
Fa
ilu
re
Ign
to
sto
or
ing
p
tra
ffi
cs
ign
Pa
al
rki
ng
vio
Dr
ivi
lat
ng
ion
a wr

on
g
wa wa
ys yo
tre n
in
et
r

0

Figure 2. Violation history of first parties in accidents for the previous
five years

record from the previous five
years. Compared with second
parties, the first parties had ahigher violation rate for all typesof violations. This seems to indicate that the driving etiquette ofdrivers who bear primary

responsibility for accidents is worse than that of others involved in the accidents.

198｜Practice2-3. Regional trends in violations and their causes
To better understand theregional characteristics ofserious traffic violations, we
examined cities and prefectures with particularly highSignificantly higher

Average: 6.12%

Significantly lower
Shimane: 13.84%

rates of repeated willful violations, such as ignoring traffic
signals, speeding, and drunk
driving (Fig. 3). Particularly
notable were ignored traffic
lights in Osaka and drunk
driving rates in Okinawa. We

Hokkaido: 12.62%

Osaka: 16.22%

Ignoring traffic signal(3 or more)
Speeding(3 or more)
Drunk driving(2 or more)（％）

High drunk driving arrest rate
Okinawa: 1.13%

14.724 ave＋3σ〜
11.857 ave＋2σ〜
8.990 ave＋σ〜
6.123 ave〜
3.256 ave−σ〜0.389 ave−2σ〜

Figure 3. Percentage of repeated violations by first parties in traffic accidents

discussed the latter finding
with the Okinawa prefectural
police, who gave the following reasons for the high rates of drunk driving:• Okinawan drinking culture: starting to drink at late hours, the popularity of awamori (a local
beverage with a particularly high alcohol content), and the custom of passing drinks around.
• High reliance on automobiles because of lacking public transportation infrastructure and theprevalence of parking lots at drinking establishments.
To cope with this situation, efforts to combat drunk driving are concentrated between 2:00 and 6:00
a.m., when most accidents due to driving under the influence of alcohol occur. Moreover, since about
five years ago, early-morning operations have been conducted to prevent driving with an alcohol
hangover.
Such drunk driving enforcement efforts require significant time, and in recent years have become
inefficient. There are limits to how much effort can be exerted, so ways to further reduce accidents is a
topic requiring further study.
2-4. Planning efforts based on numbers of traffic accidents and violations
As a simple method for investigating the effect of traffic enforcement, we created a plot showing thenumber of traffic accidents and number of traffic enforcement incidents.
Figure 4 shows the relation between the number of traffic accidents and the number of traffic
enforcement incidents by police station jurisdiction for individual town areas. The area covered isdivided into four zones (1–4), based on the average number of citations issued and average number oftraffic accidents.
Zone 3 has a low number of both citations and accidents. We therefore consider this area to besatisfactorily maintaining the status quo. Zone 4 has many citations and few traffic accidents. Areas

in this Zone wheretraffic enforcement(Incidents)

is considered excessive may there-

100

in areas where accident suppression
is considered necessary, traffic enforcement efforts

120
Traffic accidents

fore require policy revisions, and

140

②

80
60
40

Average number of citations

Traffic safety and traffic enforcement｜199

①

④

③

20
0
0

50

100

Number of incidents

Average number of accidents

150

200 (Incidents)
Utsunomiya City traffic citation data for 2005

Arranged by category①Improvements of traffic citations②Strengthened focus on enforcement③Maintaining current enforcement④Maintaining current enforcement

Figure 4. Example measures based on number of traffic accidents and number of incidents

may need to becontinued. Zone 1 has a many traffic citations but also many traffic accidents. Traffic enforcement efforts should continue in this area, but policies should also include consideration of other traffic safetymeasures such as improvement of the traffic environment. Finally, there were more traffic accidents
in zone 2 than in the other areas but the number of citations was below average. This likely indicates aneed to focus on strengthening traffic enforcement in this area.

3. Conclusions
This project performed a scientific investigation of the relation between traffic enforcement and traffic
accidents on the basis of a summary of statistical data from the results of previous research. The results
indicate that the relation between traffic accidents and traffic enforcement is strongly associated with
regional characteristics, and that investigations should be performed on a regional basis.
The following is a summary of our major findings.
• Traffic enforcement has the effect of decrease the occurrence of frequent traffic accidents.
• First parties in traffic accidents are typically poor drivers with a history of repeated traffic
violations.
• Repeated violations tend to be most common for drivers aged 25–34 years and to decreasebeyond that age range.
• Traffic enforcement varies according to the conditions of individual cities and prefectures, andpolicies best suited to each locale are required.

4. Future outlook
Connecting the results of this research to a reduction in the number of accidents in actual society will
fundamentally require consideration of measures on a regional basis. In 2013, we published Kotsu tori­
shimari handobukku (the Handbook for Traffic Enforcement) to promote traffic enforcement that is
effective for suppressing accidents. We hope this work will lead to efforts in accordance with the actual
regional situation surrounding traffic accidents.

200｜PracticeInterdisciplinary research on the criminal
charge of dangerous driving causing death orserious injury
1. Background and goals
Dangerous driving causing death or serious injury is the formal crime for when drivers intentionallydrive dangerously and the death or serious injury of another person or persons results. It is a natural
reaction, from a certain point of view, to debate whether drivers should be charged with the same crime
when tragic traffic accidents occur. Furthermore, in recent years, whether drivers can be charged withthe crime when driving under the influence of alcohol, driving with diseases that potentially cause disturbances of consciousness, or driving without a driver’s license has also become a major social problem
when the death or serious injury of others results. A new bill is under preparation to include acts thathave not previously been considered to constitute dangerous driving causing death or serious injury.
Such legislative response is certainly timely, but to properly proceed with the new bill without making penalties too strict, the law should be interpreted in line with the legal consciousness and the concept of justice among citizens. It is also necessary to scientifically investigate the adverse effects on driving of alcohol or drug use or diseases with potential disturbances of consciousness and publish the data
to promote public awareness of dangerous driving.

2. Research content
Prior to the drafting of the above amendment, we conducted a study to deepen fundamental understanding of dangerous driving causing death or serious injury. Specifically, items related to the amendment were examined and analyzed. In addition, we studied case research conducted overseas to develop
measures against habitual offenders. Here, we introduce some of our research findings.
2-1. Inspection of the amendment to include no entry roads and other types of roads
There is currently a movement to include “driving backwards on one way streets” in the amendment bill,
due to extremely hazard posed. We think this is reasonable and is worth our support.
A similarly dangerous moving violation is to overtake and pass vehicle by traversing to the rightacross a no-passing center line. However, because many drivers must inevitably pass to the right to avoid
illegally parked vehicles, it may be unwarranted to punish this act with no regard for the circumstances.
Therefore, it was practical that this act was not included in the amendment as a punishable offence.
Entering residential roads closed to non-residents or entering time-dependent no-entry roads is
Project Leader: Takeyoshi Imai
Professor, Hosei University Law SchoolInterdisciplinary research on the criminal charge of dangerous driving causing death or serious injury｜201

considered as dangerous as driving backwards on one-way streets, but this can happen accidentally andinadvertently. Therefore, drivers committing this type of violation should be punished after careful consideration of whether the drivers knew the corresponding traffic rules and regulations (negligent or
intentional) before the act was committed.
2-2. Inspection of driving without a license by type (including the case of driving
without an international driving permit)
The amendment is also considering a heavier punishment for drivers who cause moving violations
equivalent to dangerous driving causing death or serious injury while driving without a license. We can
support this directionality because the act of causing moving violations must be regarded as equally illegal to dangerous driving causing death or serious injury, and thereby the responsibility of the drivers
considered comparably heavy.
Of course, because each case is different, drivers driving without a license need to be handled carefully after fine-grained investigation of their individual circumstances. For example, some drivers may
not have a valid international driving permit in Japan because of failure to convert their license fromoverseas. When dangerous driving causing death or serious injury is committed by these drivers, theircriminal intent to drive without a license may be denied for the exceptional reason of driving without
knowledge of Japanese Law (no possibility of intentional violation).
2-3. Measures against drivers operating vehicles while intoxicated: Korea
An example of overseas measures against drivers driving while impaired (DWI) is shown below.
• DWI drivers are charged with dangerous driving causing death or serious injury if their blood
alcohol content exceeds 0.1%.
• When suspended, DWI drivers are generally required to take traffic safety classes.
• DWI drivers may be sentenced to community service (40–200 hours).
• If a violator receives a DWI after having received two previous DWIs, their drivers’ license will
be revoked even if the moving violation itself would amount for license suspension under ordinary circumstances.
• Although it was possible for authorities to confiscate vehicles from habitual DWI offenders in
the past, vehicle confiscation tends to be less frequent in recent years because confiscating vehicles and sentencing offenders to a fine is considered to be a double punishment, which may violate the Constitution.
2-4. Measures to promote social rehabilitation of drivers operating vehicles while
impaired: the United States
Another example of measures against DWI is the driving while impaired court (DWI court) in the
United States specifically for handling DWI offenders. The establishment of these courts started around2003 because of the special measures required to handle DWI offenders who engaged in repeated dangerous driving due to alcohol dependency.

202｜Practice

To understand the current situation surrounding DWI courts, we investigated the DWI court inCharlotte, North Carolina. The major findings are as
follows:• The DWI court handles only drivers who
have been found guilty and are hardcore
DWI offenders. (1)• The DWI court forms teams of professionals
to convict each driver with a comprehensive
and proper sentence.
• Although physicians are not actual members

Figure 1. Secure continuous remote alcohol monitor(Source: http://blog.aacriminallaw.com/dwi/scram-bracelet-works/)of the team, they provide appropriate external medical opinions and recommendations.
• Under the direction of probation officers on the team, drivers convicted of DWIs are randomly
subject to alcohol and drug testing 3–4 times a week. In addition, probation officers randomly
inspect the drivers’ home for alcohol or drugs.
• DWI drivers may be ordered to wear a secure continuous remote alcohol monitor (SCRAM, Fig.
1) on their ankle. This device scans the driver’s skin to monitor and record the presence ofalcohol.
• In recent years, the use of ignition interlock devices (IIDs, Fig. 2) is increasing. When DWI drivers start a vehicle equipped with an IID while intoxicated, their probation officer will be immediately informed.
• In addition, DWI drivers are ordered to use a breathalyzer at home or to install an IID in theirvehicle. IIDs prevent an equipped vehicle from being started when the device detects alcohol inthe breath of the driver.
The recidivism rate of drivers who graduate from DWI court is considerably low
compared with drivers who are sent to prison
immediately after the sentencing. Anotherexample is the program offered at the DWI
court in the State of Georgia, in which 79%(an extremely high rate) of program attendants finish. The recidivism rate of drivers
who attend the program offered by the DWI
Figure 2. Ignition interlock device(Source: http://www.lifesafernca.com/interlock-video-en/)court (regardless of completion) is 15%, while
the rate is 35% for drivers who do not attend.

(1) Hardcore DWI offenders: Drivers operating a vehicle with a blood alcohol content of 0.15 or above, or drivers operating a vehicle
under the influence of alcohol after having been convicted of a DWI.

Interdisciplinary research on the criminal charge of dangerous driving causing death or serious injury｜203

3. Conclusions
The intent of the above amendment as a measure against dangerous driving causing death or serious
injury is tenable, and this review investigated the actual factors (mechanisms underlying dangerous
driving and the cultivation of public awareness on prevention of dangerous driving) that could serve as
the foundation of the bill. In this study, we also investigated advanced measures used overseas torespond to dangerous driving, such as DWI courts and IIDs. These measures merit attention in terms ofproper punishment of and social rehabilitation for drivers who are convicted of dangerous driving causing death or serious injury.

4. Future outlook
To effectively utilize the present findings to reduce traffic accidents in the real world, it is essential todesign and develop feasible measures. We plan to investigate multidirectionally whether a similar interlocking device or DWI court program may be applicable in the context of the Japanese legal system.

204｜Practice

Smoothly promoting urban development fortransportation through collaboration between
government and local organizations
1. Background and goals
For promoting urban development for transportation, there are a growing number of cases where localorganizations are created and these organizations work in cooperation with the government. However,rules have not been established regarding appropriate roles for each side, leading not only to insufficient
communication but also situations where the two parties fall into rivalry.
This project aims at deepening the discussion of considerations and methodologies for promoting
efficient and constructive cooperation between local organizations and government in specific areas,
and thereby to obtain useful general knowledge.

2. Research content
2-1. Efforts toward consensus building in the Yanaka district
The Yanaka district in Taito ward, Tokyo, has a population of approximately 10,000 people. The district
is notable for containing many temples and wood houses from the Edo period and earlier. The district
faces traffic problems such as narrow streets that have become shortcuts for cars traveling at excessively
high speeds, as well as disaster prevention problems caused by stretches of wooden housing along narrow streets, resulting in the district being classified as a potentially dangerous area in terms of disasterprevention.
The most pressing traffic problem is the use of
the narrow residential roads of the district as shortcuts
for motor vehicles. This both increases danger to pedestrians and creates traffic-related problems such as noiseand vibration in houses along these roads. Time-based
restrictions on automobile egress have been establishedfor roads frequently used as shortcuts, but such regulations are often ignored. There have been other attempts
at improving the situation, but through traffic is a probFigure 1. Motor vehicles using residential roads
as a shortcut

lem affecting a wide area, and so far no definitive solution has been found.

Project Leader: Hisashi Kubota
Professor, Civil and Environmental Engineering, Graduate School of Science and Engineering, Saitama University

Smoothly promoting urban development for transportation through collaboration between government and local organizations｜205

Year

Initiative

Government

Residents

Core members
Problem recognition

Participatory traffic study“Uninvited” briefings
Prior consultation withgovernment to confirm
feasibility

Consideration of proposed measures in workshops
Application of participatory traffic simulation

Planning

Survey of residents’ opinions
in response to the traffic
environment and related policies

Content

Prior consultation withgovernment to confirm

Organization ofproblematic points

Multiple proposals of specific measures through workshops

feasibility
Prior consultation withlocal organizations to
spread knowledge

Consensus building

Survey of residents’ opinions
in response to specificproposed measures
Proposals compiled“Best efforts”
by mayor

Proposal submitted to the Mayor from the Town Planning Council
Pilot survey with resident participation

Development of government projects through resident participation(Urban development grant projects)

Preparation for
handoff of plan
to government

Figure 2. The consensus-building process of urban planning for transportation in the Yanaka district

The construction of large-scale apartments in the area has provided an opportunity for attempting tosolve these problems. Toward that end, the Yanaka Town Planning Council was formed with the goal of
constructing a cooperative framework between government and residents.
(1) Proposed plan
To investigate each theme concretely in urban planning, in the summer of 2003 the Yanaka Town Planning Council established three groups: the Disaster Prevention Subcommittee, the Environment Subcommittee, and the Traffic Subcommittee. The Traffic Subcommittee was formed with the goal of investigating strategies for dealing with important traffic problems in consideration of the overall urban
development plan for the Yanaka district. The Traffic Subcommittee created a Yanaka district urban
planning workshop as a way of involving all district residents in considering methods for improving
local traffic problems.
The workshop was held 19 times between September 2003 and February 2006, providing a forum
for participants to learn about traffic problems and to discuss potential solutions. At the 14th and 15th
workshops, held in 2005, the results were presented of a survey that will be described below. Proposals
for solutions to local traffic problems were summarized into a document, and based on the results of theworkshops and surveys, the residents of the Yanaka district requested cooperation from the mayor of
Taito ward in improving the traffic problems.

206｜Practice(2) Consensus building
For the purpose of consensus building between the government and residents regarding solutions to thetraffic problems, two questionnaire surveys were performed in 2004 and 2005. All residents of juniorhigh school age and older in the Yanaka district were included. A follow-up questionnaire survey was
also conducted, targeting a sampling of households that did not respond to the initial survey. The questionnaire investigated awareness of traffic problems among residents in the Yanaka district.
Overall, what do you think about the current system, in which the local Town Planning Council
first considers proposals that are then implemented as specific ward projects?

0%

LegendN=384

10%

No answer

6.5%

20%

30%

I think it is good40%

I think it issomewhat good

40.4%

50%

60%

I haveno opinion

70%

I do not think
it is very good

34.9%

80%

I do not think
it is good at all

90%

100%

I do not know

10.9%

3.1%
1.8% 2.3%

Figure 3. Resident survey results(3) Handoff to government
The workshops and resident questionnaires resulted in two proposals for methods to take the first step
toward improving traffic: installing physical devices on roads to lower vehicle speeds, and finding ways
to improve enforcement of current traffic restrictions.
From this, a pilot survey with resident participation was performed, in which speed humps were
installed along two residential roads in the district
between February 17 and March 3, 2007. Speed humps
are humps intentionally installed on roads to lower
automobile speeds.
At the same time, handmade mobile bollards(barricades such as those used during road construction) were installed to prevent the entrance of automobiles into residential streets. The handmade bollards
Figure 4. An experimentally installed rubber
speed hump. Such experiments allow area
residents to experience and evaluate impacts
and effects. Noise and vibration is suppressed by
the speed hump’s sinusoidal shape.

were installed between February 20 and 23, 2007, andthe mobile bollards were installed between February 20
and 22.
Resident questionnaires indicated a 70%
approval rate for speed hump installation. Only 30% ofSmoothly promoting urban development for transportation through collaboration between government and local organizations｜207

residents responded “I think it isgood” or “I think it is somewhat
good” regarding the bollards, but
this does not necessarily indicate
dissent; most responses were “noresponse,” “no opinion,” or “I
don’t know.”

3. Conclusions

Figure 5. A traffic bollard produced based on ideas from children

Obtained knowledge includes theimportance of specific acknowledgment by residents themselves regarding place-setting for discussions, information sharing, barrierfree participation, and resident organization activities; the desirability of government and resident organizations coexisting for as long as possible for a smooth handoff to government; and the fact thatorganizations for discussion do not function as organizations for building consensus.

4. Future outlook
The implemented residential street safety features have spread nationwide; one example is the “Zone 30”
initiative, which establishes zones within which the speed limit for all roads is 30 km/h or less. New
devices are also being tested including “rising bollards,” which were installed in 2013 as a social experiment in Niigata City and also considered in the Yanaka district. Residential streets are an important target for further promotion of traffic safety in Japan, and as such require further safety measures andresearch.

208｜PracticeRealization of earthquake disaster crisis
management and a society with safe andsecure transportation
1. Background and goals
The Great East Japan Earthquake was an unprecedented disaster that shook the foundation of Japanesesociety, which was previously expected to be safe and secure. IATSS was formed with the goal of contributing to the realization of a society with ideal transportation, and in the many years since its establishment, has performed interdisciplinary and international research studies toward that end. In the faceof the disaster, however, the question has arisen as to how the association can contribute to the reconstruction of the affected areas and the creation of new regional communities.
As a result of discussion, IATSS recognized that it was particularly important for a society to havethe three qualities: compactness/connectedness, redundancy and resilience. Taking these as keywords,
we have collected proposals from five viewpoints: construction of resilient regional communities, promoting information management and awareness, the creation of new local industries, transportation
systems with coexistence functions, and the legislation of liability rules and laws.
We hope that these proposals will contribute to the future recovery and reconstruction in disasteraffected areas, and that widespread development of the introduced measures will contribute to creatinga society with safer and more secure transportation. Below we introduce several examples of the proposals described above.

2. Research content
2-1. Constructing a resilient society through smart choices(1) Network-type compact cities
A network-type compact city is one in which the various attractive features of the city are consolidated(compacted) into multiple hubs, which are connected (networked) by various modes of transportation.
Such a city has various functional units such as commercial centers, manufacturing centers, and tourism
sites, which are intensively developed within a certain range and connected by various modes of transportation such as walking, bicycling, public transportation, and automobiles.
Compactness does not simply refer to the overall city as being in one place, but rather indicates theefficient aggregation of various attractive city features within suitable locations. It refers to aggregating

Project Leader: Kazuhiko Takeuchi
Director and Professor, Integrated Research System for Sustainability Science (IR3S), Todai Institutes for Advanced Study (TODIAS),The University of Tokyo

Realization of earthquake disaster crisis management and a society with safe and secure transportation｜209

Attraction B
Attraction A

Attraction C

Attraction D

Figure 1. Network-type compact city

limited resources to enhance the attractiveness of sites,
and interconnecting these attractive sites via various
modes of transportation. Compactly connecting suchaggregated sites (giving them compactness/connectedness) leads to ensuring mutual complementarity (redundancy) even if part of the city is affected by disaster, andflexibly performing recovery activities in other areas
increases the resilience of the city as a whole.
City compactness is generally a result of repeatedrelocation of individual sites, and requires many years. In
disaster reconstruction, on the other hand, there is a pos-sibility of rapid recovery and consolidation. Rebuilding a disaster-affected city a model city for local
governments throughout the country can provide an inspiration for overcoming the damage and tragedy of natural disasters.
(2) Multilayered transportation networks
Reconstruction following an earthquake disaster presents
Hierarchy of urban transportation
the opportunity for reconstructing the hierarchy of transShinkansen
High-speed travel
Inter-city travel
Expressways
trainsportation systems in heavily damaged cities. High-speed
Railwaystraffic channels in particular should be preferentially
Light rail transit
Intra-city travel
Highways
Main bus routes
secured to allow transport and delivery of both goods in
Community
busesInter-region travel
Residential roads
Low-speed travel
normal situations and disaster-related goods in emergenTaxis
cies. Another necessity is the development of public
Automobiles Public transportationtransportation networks to better accommodate a superFigure 2. Image of hierarchy of urban
aging society. The key to sustainable use of public transtransportation
portation will be the development of transportation systems that can be stably utilized, as well as high-intensity utilization of the land surrounding train stations
and bus stops.
In this way, appropriate division of roles between automobile and public transportation can ensure
redundancy of transportation functions. Establishing sufficiently wide evacuation routes will allowsmooth evacuations from low-lying areas to high ground, further improving post-disaster resilience.
From a variety of viewpoints, such as supporting disaster victims’ ability to travel to school andwork, and allowing transport of recovery-related goods, there is also a need for improving transportation networks between adjacent cities. Interconnecting cities over ranges sufficiently wide to include
disaster-affected areas will improve redundancy of the region as a whole, as well as its resilience to natural disasters.
2-2. Creating a new commons for supporting local industry
Key industries in disaster-affected areas include agriculture, forestry and fisheries. In the case of the210｜PracticeGreat East Japan Earthquake, these industries in particular were severely affected by the tsunami andnuclear power plant accident. Even before the earthquake, the affected area was experiencing stagnationof these industries due to reduced population and an aging labor force. What is needed in this area is a
new business model for redevelopment, one that takes advantage of the fine mosaic structure of land
and water usage that is characteristic of Japan.
Developing such a business model and tying it to regional redevelopment will require developing
new systems for cooperative resource management involving companies, nonprofit organizations, andcity residents. We propose such a model, which we call the “new commons.” Unlike the traditional concept of a commons—a place maintained for the common good—it is necessary to foster the concept of acommons that allows participation by a variety of stakeholders.
Along with redevelopment of agriculture, for未 来 の 農 村

下は水を張り水田機能は維持
期間限定のプロジェクト

亀田郷

水

亀田郷以外では以下の可能性も

木質ペレット

牧草地利用

余った電力は系統へ売電

estry and fisheries as economically advantageous,
high value-added industries, the promotion of eco-

老人世帯への電力供給とモニタリングの一体化

tourism and environmental education will beneeded to gain outlooks on regional revitalization.
There are increased expectations being placed on
renewable energy such as solar, wind, and biomass
as a consequence of the nuclear power plant accident, but the creation of new regional industries
through introduction of concepts such as co-harFigure 3. Image of rural area of the future
vesting (reconciling renewable energy production
Source: Energy Sustainability Forum(The University of Tokyo IR3S, Showa Shell Sekiyu K.K.)
with biological production) will likely be vital
toward realizing renewable energy in rural areas.
This will require introducing systems for co-management of natural resources into regional communities with consideration of regional circumstances, and building sustainable societies that are in harmony
with nature.
（病院との連携）

休耕田、
飼料米田、
不採算田のメガソーラ利用

弱電を利用した防食◇資金は有志（農家に限定せず）の共同出資◇農家は、出資しても良いし、土地賃料収入でも可（固定資産税＋αで貸す）

ショッピングセンター

病院

ポンプ室

畜舎用ファン

ホットスポット解消のファン

亀田郷本部

苺・菊など電照のLED

コミュニティバッテリーハウス（夜間消費と対災害用）

・植物工場
・ヒートポンプ等学校

ビニールハウス

学校での利用

畜舎

PHV/
V/
V EV

通勤用マイカー電化

水路斜面にソーラーパネル（雑草除去の機能兼ねる）

農家屋根へのソーラー

コミュニティバス
ターミナル

トラクター等の電化とソーラーによる充電

小型ポンプ

LED街灯（稲穂型）

電気自転車ベース

独自運営のコミュニティ
バスの統一と電化

降雪時の融雪パイプ

2-3. Construction of a transportation system for coexistence of functions between ordinaryand emergency times (Evaluation of quality of life as evacuees with consideration of
traffic quality)
We propose a method for evaluating whether evacuees living in shelters or temporary housing duringreconstruction maintain a certain quality of life (QOL), incorporating into the appraisal considerationof quality-of-trip (QOT).
Traditional traffic evaluations consider quantitative values such as degree of congestion, length oftraffic jams, and point-to-point travel times. We believe the problem of system evaluations of transportquality is better addressed through appraisal of QOT. Even when living in emergency shelters, there are
daily errands that people must attend to. The ease with which individuals can move to such destinations
should therefore be considered an important evaluation criterion. When individually considering movement objectives such as commuting to work or school, shopping, or personal errands, in addition toRealization of earthquake disaster crisis management and a society with safe and secure transportation｜211

distance traveled and ease of selecting methods of transportation, it is also important to consider factors
such as the steepness of hills and anxiety during night-time travel. There are also other important evaluation metrics that should be finely tuned for individual areas, such as accessibility to friends and family,
and accessibility to a community’s important cultural sites on special days for public rituals.
The quality of transportation is an important part of quality of life. A proper understanding of thisis a necessary part of efforts toward improving quality of life.

3. Conclusions and future outlook
Problems related to transportation have been a central theme in earthquake disaster reconstruction.
However, we have attempted to go beyond this, considering a more comprehensive understanding ofrecovery and reconstruction that presents proposals and cases from a multifaceted point of view.
This paper introduced several examples of proposals from viewpoints based on three keywords,
namely, “compactness/connectedness,” “redundancy,” and “resilience.” All of the proposals are collectedin “Aiming toward recovery and reconstruction of resilient regional communities: Five proposals andfifteen cases.” We hope any interested readers will refer to this collection of proposals.
At the IATSS we have provided these proposals to the world through making recommendations torelated local governments, academia, and international symposiums. We hope that such attempts havecontributed to further IATSS-related earthquake disaster recovery efforts and to international society.
These are important endeavors, and we look forward to further developments through IATSS projects.