INNOVATIVE TRAFFIC CONTROL

Technology and Practice in Europe

INNOVATIVE TRAFFIC CONTROL

Technology and Practice in Europe

International Technology

Exchange Program

August 1999
i

Innovative Traffic Control

Samuel C. Tignor

FHWA

(Team Leader)

Linda L. Brown

FHWA

J. Lynwood Butner

Virginia DOT

Richard Cunard

Transportation Research Board

Sterling C. Davis

Utah DOT

H. Gene Hawkins, Jr.

Texas Transportation Institute

(Team Reporter)

Edward L. Fischer

Oregon DOT

Mark R. Kehrli

FHWA

Peter F. Rusch

Wisconsin DOT

W. Scott Wainwright

Montgomery County Division of Traffic and

Parking Services

and

American Trade Initiatives, Inc.

&

Avalon Integrated Services, Inc.

for the

Federal Highway Administration

U.S. Department of Transportation

Washington, D.C. 20590

August 1999

Technology and Practice in Europe

Prepared by the study tour team
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ACKNOWLEDGMENTS

The trip described in this report would not have been successful without the

contributions and sacrifices of a large number of individuals. First and foremost, the

team members would like to thank the engineers and other transportation officials

from the four countries. These individuals gladly gave of their time and resources to

make us feel comfortable and to provide the team with the latest technical

information from their respective organizations. Those individuals that the team met

with are too numerous to list here, but they are listed in appendix C. In addition to

the people listed in the appendix, the team members would like to thank the behindthe-scenes individuals who worked on the logistical aspects of the trip. In many cases,

the team members may never have met these people, but we recognize their valuable

contribution to the success of this trip.

The team members would never have been able to start and successfully complete the

trip without the assistance of the staff from American Trade Initiatives, Inc. This

organization, working as a contractor to the Federal Highway Administration

(FHWA), handled the pre-trip logistics, escorted us throughout the trip, and provided

the support needed to prepare and publish this report. The team members would like

to recognize the following staff of ATI:

• Joe Conn for his guidance and assistance in organizing the trip,

• John O’Neill for his guidance, counsel, and leadership as our escort during the

tour, and

• Alexandra Doumani for her assistance in preparing the team report and

making the travel arrangements.

Of course, this trip would not have been possible without the support and funding

from the FHWA Office of International Programs. In particular, the team members

would like to thank Donald Symmes and Hana Maier from that office for sponsoring

the trip and allowing team members to observe and report on practices in European

countries.

Finally, the team members would like to express their appreciation to the many

individuals who served as interpreters throughout their trip. Although many of our

hosts spoke excellent English, having an interpreter familiar with the technical terms

of our profession was of great assistance to the team.
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FHWA INTERNATIONAL TECHNOLOGY

EXCHANGE PROGRAMS

The FHWA’s international programs focus on meeting the growing demands of its

partners at the Federal, State, and local levels for access to information on state-ofthe-art technology and the best practices used worldwide. While the FHWA is

considered a world leader in highway transportation, the domestic highway

community is very interested in the advanced technologies being developed by other

countries, as well as innovative organizational and financing techniques used by the

FHWA’s international counterparts.

INTERNATIONAL TECHNOLOGY SCANNING PROGRAM

The International Technology Scanning Program accesses and evaluates foreign

technologies and innovations that could significantly benefit U.S. highway

transportation systems. Access to foreign innovations is strengthened by U.S.

participation in the technical committees of international highway organizations and

through bilateral technical exchange agreements with selected nations. The program

is undertaken cooperatives with the American Association of State Highway

Transportation Officials and its Select Committee on International Activities, and the

Transportation Research Board’s National Highway Research Cooperative Program

(Panel 20-36), the private sector, and academia.

Priority topic areas are jointly determined by the FHWA and its partners. Teams of

specialists in the specific areas of expertise being investigated are formed and sent to

countries where significant advances and innovations have been made in technology,

management practices, organizational structure, program delivery, and financing.

Teams usually include Federal and State highway officials, private sector and

industry association representatives, as well as members of the academic community.

The FHWA has organized more than 30 of these reviews and disseminated results

nationwide. Topics have encompassed pavements, bridge construction and

maintenance, contracting, intermodal transport, organizational management, winter

road maintenance, safety, intelligent transportation systems, planning, and policy.

Findings are recommended for follow-up with further research and pilot or

demonstration projects to verify adaptability to the United States. Information about

the scan findings and results of pilot programs are then disseminated nationally to

State and local highway transportation officials and the private sector for

implementation.

This program has resulted in significant improvements and savings in road program

technologies and practices throughout the United States, particularly in the areas of

structures, pavements, safety, and winter road maintenance. Joint research and

technology-sharing projects have also been launched with international counterparts,

further conserving resources and advancing the state-of-the-art.

For a complete list of International Technology Scanning topics, and to order free

copies of the reports, please see the last page of this publication.

Website: www.international.fhwa.dot.gov

E-Mail: international@fhwa.dot.gov
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TABLE OF CONTENTS

LIST OF FIGURES ......................................................................................................... xi

LIST OF TABLES .......................................................................................................... xiii

EXECUTIVE SUMMARY .............................................................................................. xv

TRAFFIC CONTROL DEVICES ............................................................................ xvi

FREEWAY CONTROL ........................................................................................... xvii

OPERATIONAL PRACTICES ............................................................................... xvii

INFORMATION MANAGEMENT ....................................................................... xviii

ADMINISTRATIVE PRACTICES .......................................................................... xix

RECOMMENDATIONS ........................................................................................... xx

CHAPTER 1 - INTRODUCTION .................................................................................... 1

TRIP PLANNING ....................................................................................................... 1

Trip Objective........................................................................................................ 2

Team Members...................................................................................................... 2

Meetings ................................................................................................................ 3

Questions............................................................................................................... 3

Trip Itinerary ........................................................................................................ 3

REPORT ORGANIZATION ....................................................................................... 4

AMERICAN EUROPEAN CONTRASTS .................................................................. 5

Cultural Contrasts................................................................................................ 5

Language Contrasts ............................................................................................. 5

Engineering Contrasts ......................................................................................... 6

CHAPTER 2 - TRAFFIC CONTROL DEVICES ............................................................. 9

PRIMARY FINDINGS ............................................................................................... 9

Tiger Tail ............................................................................................................... 9

All-White Pavement Markings .......................................................................... 11

OTHER OBSERVATIONS ....................................................................................... 15

Signs .................................................................................................................... 15

Countdown Markers for Exit Ramps ........................................................... 16

More Intensive Sign Colors .......................................................................... 18

Arrowhead Shaped Destination Signs......................................................... 19

Internal Sign Illumination ........................................................................... 20

Use of Dotted Border for Trailblazing ......................................................... 20

Guide Sign Sheeting Types .......................................................................... 20

Variations in Alphabet Stroke Width .......................................................... 21

Freeway Exit Direction Signs ...................................................................... 22

Markings ............................................................................................................. 24

Horizontal Signing ........................................................................................ 24

Chevrons for Vehicle Spacing ....................................................................... 26

Colored Pavements ....................................................................................... 27

Pedestrian Treatments ....................................................................................... 27

Raised Crosswalks ........................................................................................ 27

Flashing Yellow on Pedestrian Clearance ................................................... 28
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Audible Pedestrian Signals .......................................................................... 29

Advance Pedestrian Pavement Markings ................................................... 29

Work Zone Visibility ........................................................................................... 29

Worker Visibility Enhancements ................................................................. 29

Vehicle Visibility Enhancements ................................................................. 30

Work Zone Traffic Control ............................................................................ 30

Rotary Intersections ........................................................................................... 33

CHAPTER 3 - FREEWAY CONTROL ........................................................................... 35

PRIMARY FINDINGS ............................................................................................. 35

Variable Speed Control ....................................................................................... 35

Lane Control Signals .......................................................................................... 37

Incident and Queue Detection and Protection .................................................. 38

OTHER OBSERVATIONS ....................................................................................... 40

Rolling Freeway Block ........................................................................................ 40

Shoulder Detection ............................................................................................. 40

CHAPTER 4 - OPERATIONAL PRACTICES............................................................... 41

PRIMARY FINDINGS ............................................................................................. 41

Intelligent Speed Adaption ................................................................................ 41

Self Optimizing Signal Intersection Control..................................................... 42

OTHER OBSERVATIONS ....................................................................................... 45

Signals ................................................................................................................. 45

Use of Historical Loop Data During Loop Failure Conditions ................... 45

Coordinated Signal Preemption Strategies................................................. 45

Safety ................................................................................................................... 46

Automated Enforcement .............................................................................. 47

Emergency Phones ........................................................................................ 48

Design Features .................................................................................................. 48

Elevated Police Patrol Bays ......................................................................... 49

CHAPTER 5 - INFORMATION MANAGEMENT........................................................ 51

PRIMARY FINDINGS ............................................................................................. 51

Symbolics............................................................................................................. 51

Display of Travel Time Information .................................................................. 53

OTHER OBSERVATIONS ....................................................................................... 54

Consistency in Variable Message Signs ............................................................ 54

Real-Time Parking Information......................................................................... 55

Traffic Information on FM Radio....................................................................... 56

RDS-TMC ............................................................................................................ 57

MATTISSE .......................................................................................................... 57

Private Sector Collection of Traffic Data for Traveler Information................. 58

CHAPTER 6 - ADMINISTRATIVE PRACTICES ......................................................... 59

PRIVATE SECTOR ................................................................................................... 60

TECHNOLOGY DEVELOPMENT.......................................................................... 61

SAFETY .................................................................................................................... 61

OTHER OBSERVATIONS ....................................................................................... 62

Integration of Transportation Modes ................................................................ 62
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Policy ................................................................................................................... 62

Coordination........................................................................................................ 62

In-Vehicle Messages ........................................................................................... 62

CHAPTER 7 - RECOMMENDATIONS ........................................................................ 63

TRAFFIC CONTROL DEVICES ............................................................................. 63

Primary Recommendations ................................................................................ 63

Tiger Tail Marking ........................................................................................ 63

All-White Pavement Markings .................................................................... 64

Additional Recommendations ............................................................................ 65

FREEWAY CONTROL ............................................................................................. 67

Primary Recommendations ................................................................................ 67

Variable Speed Control ................................................................................. 67

Lane Control Signals .................................................................................... 67

Incident and Queue Detection and Protection ............................................ 68

Additional Recommendations ............................................................................ 68

OPERATIONAL PRACTICES ................................................................................. 68

Primary Recommendations ................................................................................ 68

Intelligent Speed Adaption........................................................................... 69

Self Optimizing Signal Intersection Control ............................................... 69

Additional Recommendations ............................................................................ 70

INFORMATION MANAGEMENT .......................................................................... 70

Primary Recommendations ................................................................................ 70

Symbolics....................................................................................................... 71

Display of Travel Time Information ............................................................ 71

Additional Recommendations ............................................................................ 71

ADMINISTRATIVE PRACTICES ........................................................................... 72

IMPLEMENTATION EFFORTS ............................................................................. 72

CHAPTER 8 - REFERENCES ....................................................................................... 75

APPENDIX A - TEAM MEMBERS ............................................................................... 77

TEAM MEMBERS AND AFFILIATIONS .............................................................. 77

TEAM MEMBER BIOGRAPHIES .......................................................................... 78

APPENDIX B - AMPLIFYING QUESTIONS............................................................... 83

APPENDIX C - CONTACTS IN HOST COUNTRIES ................................................. 87

APPENDIX D - PROBLEM STATEMENTS ................................................................. 89
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LIST OF FIGURES

Figure 1. Team members .................................................................................................. 2

Figure 2. Mid-trip team meeting ..................................................................................... 4

Figure 3. Tiger tail pavement markings on entrance ramps to English freeways ..... 10

Figure 4. Before-and-after application of tiger tail marking on exit ramp ................. 10

Figure 5. Edge line in Lundby Tunnel, Sweden............................................................ 12

Figure 6. Airport markings near Frankfurt, Germany ................................................ 12

Figure 7. Intersection markings, France ....................................................................... 12

Figure 8. Markings on rural freeway, France ............................................................... 12

Figure 9. Markings on freeway exit ramp, France ....................................................... 12

Figure 10. Markings on rural freeway, France ............................................................. 12

Figure 11. Markings for exit ramp on rural freeway, France ...................................... 13

Figure 12. Markings for rural highway, France............................................................ 13

Figure 13. Markings for rural intersection, France...................................................... 13

Figure 14. Markings on rural freeway, France ............................................................. 13

Figure 15. Markings for rural highway, France............................................................ 13

Figure 16. Demarcation of passing/no passing zone, France ....................................... 13

Figure 17. Photo 1 – Approach to rural intersection with no passing zone, France ... 14

Figure 18. Photo 2 – Approach to rural intersection with no passing zone, France ... 14

Figure 19. Photo 3 – Approach to rural intersection with no passing zone, France ... 14

Figure 20. Photo 4 – Approach to rural intersection with no passing zone, France ... 14

Figure 21. Approach to rural intersection, England ..................................................... 14

Figure 22. Lane line extensions carried through intersection (both directions),

 Germany........................................................................................................ 14

Figure 23. Yellow markings in work zone, Germany.................................................... 15

Figure 24. Yellow markings in work zone, Germany.................................................... 15

Figure 25. Yellow markings in work zone, Germany.................................................... 15

Figure 26. Crosshatch in intersection, England ........................................................... 15

Figure 27. Countdown markers for exit ramp .............................................................. 17

Figure 28. Comparison of xy color plots for U.S. and Europe ...................................... 18

Figure 29. Arrow shaped sign at exit ramp gore, Germany ......................................... 19

Figure 30. Arrow shaped sign, England ........................................................................ 19

Figure 31. Arrow shaped signs at rotary intersection, France .................................... 19

Figure 32. Arrow shaped signs mounted on backboard, England ............................... 19

Figure 33. Use of dotted border (for E45) in sign, Sweden .......................................... 20

Figure 34. Use of parenthesis in sign, England ............................................................ 20

Figure 35. Use of parenthesis (for A41) in pavement markings, England .................. 20

Figure 36. Freeway exit direction sign, Sweden ........................................................... 22

Figure 37. Freeway exit direction sign, Sweden ........................................................... 22

Figure 38. Freeway exit direction sign, Germany ........................................................ 22

Figure 39. Freeway exit direction sign, Germany ........................................................ 22

Figure 40. Freeway exit direction sign, Germany ........................................................ 23

Figure 41. Freeway exit direction sign, France ............................................................ 23

Figure 42. Freeway exit direction sign, France ............................................................ 23

Figure 43. Freeway exit direction sign, England .......................................................... 23

Figure 44. Freeway exit direction sign, England .......................................................... 23

Figure 45. Highway numbers in lanes, England .......................................................... 25
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Figure 46. Highway numbers in lanes, England .......................................................... 25

Figure 47. Highway numbers and destination names in lanes, England ................... 25

Figure 48. Stop marking, England ................................................................................ 25

Figure 49. Yield pavement markings, Sweden ............................................................. 25

Figure 50. Bus lane marking, Sweden .......................................................................... 25

Figure 51. Intersection directional and crossing markings, Sweden .......................... 26

Figure 52. Intersection marking, England .................................................................... 26

Figure 53. Bike marking, France ................................................................................... 26

Figure 54. Abbreviated markings carried through intersection, Germany ................ 26

Figure 55. Chevron marking sign, England .................................................................. 26

Figure 56. Bus lane colored pavement, England .......................................................... 27

Figure 57. Green pavement where bike lane intersects vehicle lane, France ............ 27

Figure 58. Raised crosswalk, Sweden ........................................................................... 28

Figure 59. Markings on approach to pedestrian crossing, England ............................ 29

Figure 60. Worker vest, Sweden .................................................................................... 30

Figure 61. Worker vests, France .................................................................................... 30

Figure 62. Maintenance vehicle, Sweden ...................................................................... 30

Figure 63. Maintenance vehicle and trailer, France..................................................... 31

Figure 64. Incident response vehicle, France................................................................ 31

Figure 65. Work zone vehicle, France ............................................................................ 31

Figure 66. Police vehicle, England ................................................................................. 31

Figure 67. Police and incident response vehicles, England.......................................... 31

Figure 68. Incident response vehicle, England ............................................................. 31

Figure 69. Photo 1, Advance work zone, France ........................................................... 32

Figure 70. Photo 2, Channelizing transition to work zone, France ............................. 32

Figure 71. Photo 3, Work zone protection, France ........................................................ 33

Figure 72. Retroreflective area on cones, England ....................................................... 33

Figure 73. Strobe lights above work zone signs, Sweden ............................................. 33

Figure 74. Strobe light above temporary gore sign, Germany ..................................... 33

Figure 75. Rotary intersection, France.......................................................................... 33

Figure 76. Rotary intersection, France.......................................................................... 34

Figure 77. Rotary intersection, France.......................................................................... 34

Figure 78. Rotary intersection, France.......................................................................... 34

Figure 79. Rotary intersection, England ....................................................................... 34

Figure 80. Rotary intersection, England ....................................................................... 34

Figure 81. Rotary intersection, Sweden ........................................................................ 34

Figure 82. Variable speed control, England .................................................................. 35

Figure 83. Variable speed limits, England .................................................................... 36

Figure 84. Variable speed limit, England ...................................................................... 36

Figure 85. Variable speed limits, Germany ................................................................... 36

Figure 86. Standard speed limit sign, France............................................................... 36

Figure 87. Close-up of variable speed limit indication, England................................. 36

Figure 88. Lane control signals, Germany .................................................................... 37

Figure 89. Lane control signals on freeway with no median, England ....................... 38

Figure 90. Incident reduction signal control strategy .................................................. 43

Figure 91. Banana detectors for left turning ................................................................ 44

Figure 92. Variable speed limit sign, England .............................................................. 47

Figure 93. Variable speed limit ends sign, England ..................................................... 47
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Figure 94. Enforcement camera sign, England ............................................................ 47

Figure 95. Police Patrol Bay, England ........................................................................... 49

Figure 96. Symbols used in variable message signs .................................................... 52

Figure 97. Diversion symbols......................................................................................... 53

Figure 98. Detour symbol signs ..................................................................................... 53

Figure 99. Real-time travel time information, France ................................................. 54

Figure 100. Real-time parking information, Germany ................................................ 55

Figure 101. Real-time parking information, Germany ................................................ 56

Figure 102. Real-time parking information, Germany ................................................ 56

LIST OF TABLES

Table 1. ITC team meetings ............................................................................................. 3

Table 2. Cities and countries visited ............................................................................... 4

Table 3. Other observations for traffic control devices................................................. 16

Table 4. Comparison of British and U.S. alphabets ...................................................... 21

Table 5. Implementation presentations ........................................................................ 73
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EXECUTIVE SUMMARY

Vehicular travel is increasing throughout the world, particularly in large urban areas.

Accommodating the increased demand, while improving traffic safety, has led

transportation officials to utilize a variety of innovative traffic control practices.

These practices are used to control traffic movement and to provide road users with

better information upon which to base travel decisions. By utilizing these practices,

transportation professionals can operate the transportation system more efficiently

and safely. In recent years, traffic engineers in the United States have implemented a

number of practices to improve the overall quality of traffic flow. However, improved

traffic control is a worldwide need and many countries have also implemented

innovative traffic control practices. Recognizing the benefits that could result from an

examination of international practices, a team of traffic engineers was formed to

observe and document practices that might have value to U.S. practitioners. This scan

team effort was jointly sponsored by the Federal Highway Administration, the

American Association of State Highway and Transportation Officials, and the

Transportation Research Board.

In May 1998, a team of ten U.S. traffic engineers traveled to Europe to observe

innovative traffic control practices and identify those practices that could be

implemented in the United States. The team members represented several different

perspectives, including Federal, State, and local governments, and two research

organizations. The team members are listed in appendix A. During a two-week period,

the team visited with transportation officials in Gothenburg, Sweden; Frankfurt,

Cologne, and Bonn, Germany; Paris, France; and London and Birmingham, England.

These host officials presented information on a wide variety of traffic engineering and

traffic control topics and the team observed

many other interesting practices during the

travel between visits. At the beginning,

halfway, and end points of the trip, the team

members met to discuss their observations

and to identify those practices that might

have implementation value in the United

States. The team identified many

noteworthy practices, several of which may

have current or future value to

transportation agencies in the United

States.

This report describes the findings and

observations resulting from the scan trip. The information obtained from the trip is

organized into five chapters (Traffic Control Devices, Freeway Control, Operational

Practices, Information Management, and Administrative Practices). In each of these

chapters, the material is organized into two categories: Primary Findings and Other

Observations. The Primary Findings represent the material that the team feels has

the greatest implementation value and/or that has significant benefits if

implemented. The Other Observations represent other items that the team found

The host officials presented information

on a wide variety of traffic engineering

and traffic control topics, and the

team observed many other

interesting practices during the

travel between visits.
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EXECUTIVE SUMMARY

interesting and which may also have potential implementation value in the United

States. In some cases, the practices can be implemented with little or no change in

current U.S. practices or standards. In other cases, implementation must follow

research that addresses U.S. aspects related to a topic. The following sections of this

summary describe the Primary Findings from each chapter and list the topics

associated with the Other Observations. An introductory chapter precedes these five

chapters and the team’s recommendations are summarized in the last chapter. There

are also several appendices that support the information in the report.

TRAFFIC CONTROL DEVICES

As the team traveled between and within countries, they had an opportunity to

observe various European practices for traffic control devices. Many of these practices

are significantly different from the equivalent U.S. practice, if one exists. The two that

the team members believe would have the greatest potential value in the United

States are the tiger tail marking used on freeway entrance and exit ramps and the

all-white system of pavement markings used throughout Europe. These two practices

are summarized below and described in detail in the Primary Findings section of

chapter 2.

The tiger tail marking is an innovative pavement marking pattern that is used on

multilane freeway entrance and exit ramps in England. The marking separates

multiple lanes by using a wide painted buffer. The buffer separates the merge/diverge

points of each lane, reducing turbulence and improving operations as traffic enters or

leaves the mainline.

As the team traveled through Europe, there were very impressed by the quality of the

pavement marking systems and the ability to communicate information to drivers

through the use of only white markings.

The Europeans use a wide variety of

pavement marking patterns (line width,

number of lines, line/gap ratio, etc.) to

convey the necessary information to road

users. They also use significantly more

marking material than is commonly used

in the United States. The team members

feel that the European system of all-white

markings could provide some benefits and deserves close examination to determine

potential implementation value in the United States.

The team also observed many other European practices related to traffic control

devices. These practices include: countdown markers for exit ramps, more intensive

sign colors, arrowhead shaped destination signs, internal sign illumination in urban

areas, use of dotted sign border for trailblazing, variations in alphabet stroke width,

horizontal signing, chevrons for vehicle spacing, colored pavements, raised crosswalks,

flashing yellow on pedestrian clearance, audible pedestrian signals, worker visibility

enhancements, vehicle visibility enhancements, work zone traffic control, freeway exit

Many European practices for traffic

control devices are significantly different

from the U.S. practice, if one exists.
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EXECUTIVE SUMMARY

signs, and rotary intersections. These are

described in more detail in the Other

Observations section of chapter 2.

FREEWAY CONTROL

Many of the freeways (or motorways as they

are known in Europe) in urban areas

experience high levels of congestion.

Practitioners in all four countries have

implemented many different strategies for

controlling traffic on these congested

freeways. The three freeway control practices

that the team members feel should be

researched for possible implementation in the United States are variable speed

control, lane control signals, and incident and queue detection and protection.

One of the most interesting observations of the trip was the extent to which the host

countries use dynamic signs to present variable regulatory speed limits to drivers.

Operating agencies were able to achieve considerable traffic flow and safety benefits

on freeways by dynamically changing the speed limit based upon real-time traffic

speed and flow data. The high level of compliance with these signs was attributed to

the fact that the speeds reflect actual freeway conditions in real-time and the

presence of photo speed enforcement on some freeways.

Lane control signals were also widely used on European freeways, most commonly in

conjunction with dynamic message signs and variable speed limits. A signal is

mounted above each lane to indicate traffic conditions downstream. These signals use

red X, downward yellow diagonal arrow, and green down arrow indications to indicate

that a lane is closed, closed ahead, or open, respectively.

Freeway queue detection and protection were observed in all four countries. Sensors

(primarily loops) are placed in freeway mainlanes, and sometimes in the shoulder

lanes, to identify when queues form and the location of the back of the queue. The

operating agency uses this information to provide advance notice of the presence of a

queue. The information presented to drivers may be an advisory speed, a speed limit,

or a congestion warning message (symbol or words). Some of the response systems are

fully automated. In some locations, another or additional form of queue protection is

provided by placing incident response vehicles with flashing lights and/or dynamic

message signs on the shoulder at the end of the queue. These vehicles back up as the

queue proceeds upstream.

The team also observed many other European practices related to freeway control.

These practices include the rolling freeway block and shoulder detection, and are

described in more detail in the Other Observations section of chapter 3.

OPERATIONAL PRACTICES

Our European hosts informed the team of many unique and interesting operational

practices that they utilize in their transportation systems to control traffic. The team

The three freeway control practices that

the team members feel should be

researched for possible implementation

in the United States are variable speed

control, lane control signals, and incident

and queue detection and protection.
xviii

EXECUTIVE SUMMARY

members recommend research on two of those practices for possible implementation

in the United States: intelligent speed adaption and self optimized traffic signal

control.

Sweden has tested a system of intelligent speed adaption where drivers are alerted

inside the vehicle when they are exceeding the posted speed. The system can also

directly limit the vehicle’s speed.

An interesting traffic signal operational

practice was presented by the Swedish

officials. At isolated intersections, they are

testing Self Optimized Signal Control

(SOS) as a means to improve safety. SOS is

a sophisticated system of detection and

traffic signal controller logic which enables

the change in right-of-way between

opposing traffic movements to be made

based on assessing and minimizing the

safety risks for traffic on the approaches

which will be stopped. It is a dilemma zone enhancement which translates stopping

risks and cross street queue development to a cost algorithm.

The team also observed many other European practices related to operational

practices. These practices include: use of historical loop data during loop failure

conditions, innovative coordinated signal preemption strategies, automated speed

enforcement, emergency phones, and elevated police patrol bays. These are described

in more detail in the Other Observations section of chapter 4.

INFORMATION MANAGEMENT

The team members were impressed by the amount of information that European

agencies provide to road users. They have placed a strong emphasis on presenting the

information where drivers can best use it and in an easy-to-understand format.

Although the team members expected to see significant use of symbols, they were

nonetheless impressed by the extent and success of symbol use. Symbols (or

pictograms as they are more commonly termed in Europe) are widely used in variable

message signs. Typical symbols that are presented in these signs include congestion,

snow, danger, workers, and slippery pavement. Symbols are also widely used to

indicate diversion routes. These diversion symbols are based on geometric shapes.

When it is necessary to divert traffic from the freeway, variable message signs

indicate the diversion symbol to follow. The symbol is presented at all decision points

along the diversion route.

The team learned that freeway dynamic message signs are also used to provide

drivers with travel time information. One of the most impressive examples of this

practice was found on Paris freeways. There are over 200 dynamic message signs on

the outer ring road freeway, its entrance ramps, and the inner ring road that provide

real-time travel times to upcoming junctions. In a 1994 evaluation of this system, it

Team members recommend research on

two European operational practices for

possible implementation in the United

States: intelligent speed adaption and

self optimized traffic signal control.
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EXECUTIVE SUMMARY

was found that 65 percent of the motorists preferred travel time information over

congestion information.

The team also observed many other European practices related to information

management. These practices include: consistency in variable message signs, real

time parking information, traffic information on FM radio, RDS-TMC, Tegaron,

TrafficMaster,® MATTISSE, and private sector collection of traffic data for traveler

information. European transport agencies are actively pursuing partnerships with the

private sector, which includes the collection of traffic data. In several countries,

private sector firms are allowed to install, operate, and maintain supplemental traffic

detectors to enhance their own for-profit traffic information databases. These are

described in more detail in the Other Observations section of chapter 5.

ADMINISTRATIVE PRACTICES

In addition to the benefits derived from discussion and observation related to traffic

control practices, the team gained valuable insight into the administrative issues

associated with operating a transportation system. The team found that European

transportation officials place significant emphasis on “marketing” traffic engineering

practices and improvements. One of the key

observations of the team is that several of

the countries use safety benefits and

improved emergency services incident

response times instead of improved

operations or congestion reduction as

primary justification for transportation

programs when presenting them to policy

makers and elected officials. This was

particularly true for the heavily congested

freeways and highways.

The most prominent examples of the safety

emphasis were found in Sweden. The

Swedish government has adopted a safety strategy known as “Vision Zero.” The

objective of this strategy is to eliminate fatalities on Swedish highways. An example

of the emphasis on business practices was found in England, where transportation

improvements are evaluated using a “Value for Money” concept. Each improvement is

carefully assessed with respect to expenditures and expected benefits.

Several of the interesting concepts identified by the team related to the effort to

reintegrate Telematics (ITS) into the existing organizational structure and

transportation system. This concept has been initiated to ensure that the utilization

of technology is inherent within the traditional organizational components and more

readily assimilated within the political, customer, and organizational arenas as a

critical component of long-term transportation solutions.

The European emphasis on customer service was best exemplified in a French private

sector toll facility. The facility reflected a quality product in terms of infrastructure,

and demonstrated that construction, operation, and maintenance standards were

actually being exceeded to promote the future acceptance and expansion for these

The team found that European

transportation officials place significant

emphasis on “marketing” traffic

engineering practices and

improvements.
xx

EXECUTIVE SUMMARY

types of facilities. The team was also very impressed with the administrative

commitment to transportation research in several countries and the ability to manage

high-speed freeways in a safe and efficient manner.

RECOMMENDATIONS

The members of the scan team were privileged to travel to four European countries

and see firsthand many outstanding traffic control and traffic engineering practices.

Following the meetings with the host countries, the team members met to review the

findings from the trip and identify those practices which have the greatest potential

for successful implementation in the United States. The practices described as

Primary Findings represent the team’s recommendations for practices that should

receive strong consideration for implementation in the United States. In some cases,

the practices can be implemented with little or no change in current U.S. practices or

standards. In other cases, implementation must follow research that addresses U.S.

aspects related to a topic. Team members have developed several problem statements

to initiate the process of conducting that research. Team members have also begun

the process of presenting the trip findings to various professional audiences. The

implementation of the various traffic control practices will ensure our citizens receive

the maximum benefit of innovative traffic controls to save lives, enhance operational

efficiency, and improve the movement of traffic in the United States.
1

chapter one

INTRODUCTION

Vehicular travel is increasing throughout the world, particularly in large urban areas.

Accommodating the increased demand has led transportation officials to utilize a

variety of innovative traffic control practices. These practices are used to control

traffic movement and to provide road users with better information upon which to

base travel decisions. By utilizing these practices, transportation professionals can

operate the transportation system more efficiently and safely. In recent years, traffic

engineers in the United States have implemented a number of practices to improve

the overall quality of traffic flow. However, the need for improved traffic control is a

worldwide need and many countries have also implemented innovative traffic control

practices. Recognizing the benefits that could result from an examination of

international practices, a team of traffic engineers was formed to observe and

document practices that might have value to U.S. practitioners. In May 1998, the

team traveled to four European countries (Sweden, Germany, France, and England)

to observe innovative traffic control practices and identify those practices that could

be implemented in the United States. This report describes the findings and

observations of that group and includes recommendations of practices that have

potential implementation value in the United States.

TRIP PLANNING

Several years ago, the Federal Highway Administration (FHWA), in coordination with

the American Association of State Highway and Transportation Officials (AASHTO),

and the Transportation Research Board (TRB), began sending teams of

transportation officials to various countries to observe and document various

practices. The basic concept of these “scan trips” is to identify technologies and/or

practices that might have immediate or near-term implementation value in the

United States. The cost of sending a team to one or more countries and documenting

their findings in a report is significantly less than the cost of researching the

technology or practice in the United States and preparing the appropriate

documentation. In addition, the team has the benefit of observing firsthand how a

technology or practice is utilized in a real-world setting.

A scan trip begins with FHWA identifying the need to observe international practices

in a particular field. A team of experts in that field is created and meets to plan the

key aspects of the trip and develop a series of “amplifying questions” that are

submitted to the host countries. During the trip, team members meet as a group with

representatives of various organizations in each host country. The hosting

organizations are generally determined by the host country on the basis of the

amplifying questions. At various times during the trip, the team members meet to

clarify their observations and begin developing the team’s recommendations. Upon

their return, the team prepares a report describing their observations and

recommendations. Throughout the entire effort, the team’s activities are guided by an

FHWA contractor, who is responsible for the pre-trip communications with the host

countries and the logistical aspects of the trip.
2

CHAPTER 1

Trip Objective

The basic objective that FHWA established for this trip was to identify, discuss, and

document innovative traffic control (ITC) technologies, devices, and practices in four

European countries that are already implemented or that will be in the near future

(approximately 2 years). As such, the team was less interested in current research on

future technologies. The study team’s primary emphasis was on implementation, but

they were also interested in planning, installation, operation, maintenance, and

financing as it relates to innovative traffic control. In gaining an understanding of

these innovative traffic control systems and technologies, the team hoped to identify

both the similarities and differences between European and U.S. transportation

systems that might affect implementation of innovative traffic control technologies.

The team also wanted to identify problems associated with implementing the

innovative technologies and systems and the role(s) that non-government, private

entities had in both implementing and operating innovative traffic control systems.

Finally, the team wanted to observe firsthand these systems and technologies in

operation and obtain information that assesses the effectiveness of these systems and

technologies.

Team Members

The team members represented several different perspectives including the Federal

Highway Administration (Washington, D.C. and regional offices), three State

departments of transportation (Utah, Virginia, and Wisconsin), a local transportation

agency (Montgomery County, Maryland), and two research organizations

(Transportation Research Board and Texas Transportation Institute). Appendix A

lists the team members, along with their affiliations and a short biography. Figure 1

shows the team members during their visit to Sweden.

Figure 1. Team members. (From left to right) Ed Fischer, Lynwood Butner, Scott Wainwright,

Pete Rush, Linda Brown, Mark Kehrli, Rich Cunard, Sam Tignor, Sterling Davis,

and Gene Hawkins.
3

CHAPTER 1

Meetings

The team members met four times during the course of the trip development and the

actual travel. These meetings are listed in table 1. The first meeting provided an

opportunity to define the areas of greatest interest and prepare a series of amplifying

questions that the host countries could use to develop the program of presentations.

The other three meetings were held during the trip. The first meeting, held the day

before the first visit with hosting officials, provided a chance to review the objectives

of the trip and the agendas prepared by the hosting countries. Halfway through the

trip, the team met to discuss the first week’s findings and observations. Figure 1

shows the team members participating in this meeting. The team also met on the last

day of the trip to discuss the second week’s findings and observations and to decide

upon the team’s recommendations for implementation.

Questions

In order to provide our European hosts with a better understanding of the issues,

technologies, and devices of greatest interest, the team prepared a series of

amplifying questions that focused on six major topics (traffic control device systems,

real-time traffic control, safety aspects, very high speeds, visibility and lighting, and

administrative issues). Each topic included specific questions that were intended to

provide the team with a better understanding of European application of the

innovative technologies and systems. The amplifying questions developed by the team

as a result of the pre-trip meeting are listed in appendix B.

Trip Itinerary

The trip took place in the first two weeks of May 1998. Table 1 lists the countries and

associated cities visited during the trip. Appendix C lists the officials that the team

met with during the trip. These host officials presented information on a wide variety

of traffic engineering and traffic control topics and the team observed many other

interesting practices during the travel between visits.

LOCATION DATE AND TIME FRAME PURPOSE

Washington, D.C. area

Gothenburg, Sweden

Paris, France

London, England

January 6, 1998

(four months before trip)

May 3, 1998

(beginning of trip)

May 10, 1998

(middle of trip)

May 16, 1998

(end of trip)

Determine emphasis areas and develop

amplifying questions

Plan trip actions and emphasis areas

Review findings

Identify key findings and develop

preliminary team recommendations

Table 1. ITC team meetings.
4

CHAPTER 1

Table 2. Cities and countries visited.

REPORT ORGANIZATION

During the course of the trip, the team identified many noteworthy practices, several

of which are felt to have current or future value to transportation agencies in the

United States. This report presents this information in five chapters. Within each

chapter, the information is divided into two categories: Primary Findings and Other

Figure 2. Mid-trip team meeting.

Note: 1

Only the dates on which the team members met with hosting officials are listed. This

does not include travel days and weekend team meetings. 2Information obtained from the

Department of Transport in the United Kingdom pertained exclusively to England. Roads in

Scotland, Wales, and Northern Ireland are operated and maintained by separate agencies.

DATES1 COUNTRIES CITIES

May 4-5, 1998

May 6-8, 1998

May 11-12, 1998

May 14-15, 1998

Sweden

Germany

France

England2

Gothenberg

Frankfurt

Köln

Bonn

Paris

London

Birmingham
5

CHAPTER 1

Observations. The Primary Findings represent those items that the team members

feel have the greatest implementation value and/or which have significant benefits if

implemented. The Other Observations are those items that the team found

interesting and which may have some implementation value to U.S. practitioners.

AMERICAN–EUROPEAN CONTRASTS

As the team members traveled throughout the four countries, they were continually

educated on some of the significant difference between the United States and the

European countries visited. These differences were evident in many different areas,

including cultural, language (both common and technical), and engineering practices.

While the engineering differences were the focus of the trip, the other differences

impacted the gathering of information and will also impact the ability of U.S.

practitioners to implement promising technologies and practices.

Cultural Contrasts

During their travels through Europe, the team members were able to experience

many different aspects of the countries that they visited. While the focus of the trip

was on innovative traffic control, team members had the pleasure of experiencing the

people and facilities in each country. As they traveled on planes, trains, subways,

buses, taxis, and boats; and interacted with the people in each country, the team

members were able to observe firsthand many significant cultural characteristics in

the four countries they visited. As they did so, they were able to contrast these

characteristics with those of the United States. Many of these cultural characteristics

represent nothing more than a different way of living and give each area its unique

identity. However, the team members feel that some of these cultural characteristics

have a direct impact on the transportation systems in each country.

Probably the most significant cultural characteristic affecting the transportation

system is the widespread use and support of public and multimodal transportation.

While there were significant volumes of vehicular traffic in all of the countries,

Europeans are not as reliant on the automobile as Americans. This factor was an

important consideration when the team members began to evaluate innovative traffic

control practices for potential implementation in the United States. The preservation

of urban areas is also important to Europeans. Many European cities are much older

than their U.S. counterpoints. Five-hundred-year-old cities are not at all unusual. As a

result, the Europeans have a very strong sense of history and the preservation of that

history. Europeans also appear to have a generally greater respect for authority than

Americans. This leads to higher compliance with traffic control regulation and

devices. In many cases, the team identified practices that were innovative or unique,

but which have limited application in the United States due to the basic differences in

the transportation systems of the United States and Europe.

Language Contrasts

The team members were continually amazed by the ability of their hosts to

communicate with the team members in English. The majority of individuals that the

team met with were fluent in English. Even so, there are numerous terms, both

common and technical, that the team had to learn. A few of the most common
6

CHAPTER 1

European terms are listed below, followed in parentheses by the U.S. equivalent and

the European areas where the terms are used, if applicable.

• Motorway (freeway, all countries)

• Lorry (truck, England)

• Coach (bus, England)

• Carriageway (travelway or paved roadway, England)

• Dual carriageway (divided highway, England)

• Petrol (gasoline, all countries)

• Hard shoulder (paved shoulder, England)

• Vertical signs (post-mounted signs, all countries)

• Horizontal signs (pavement markings, all countries)

• Signal stage (signal phase, all countries)

• Telematics (ITS, Intelligent Transportation Systems)

Engineering Contrasts

The team was very impressed with the high level of experience, technical talent, and

professionalism we found in our visits and travels in each of the four countries. It was

obvious that their engineers have had many of years of experience in designing

solutions and managing traffic operational problems in cities and rural areas on all

classes of roadways. The team found their solutions practical, effective, and, more

often than not, new and creative. The European engineers are probably utilizing new

technologies faster than many of their U.S. counterparts. European transportation

agencies appear to be more progressive in testing and implementing new technologies

and applications of traffic control devices than in the United States. The difference

may be in large part due to the aggressive and progressive research programs which

the individual countries have, and that they are, in fact, acting as individual entities

in many of the applications they do implement. Many of the solutions we observed on

freeways are certainly more advanced than are used on U.S. freeways. Examples

include: variable speed limits with photo enforcement; rolling freeway blocks by

enforcement personnel to aid incident clearance; greater use of pavement markings to

supplement driver guidance; dedicated freeway traffic enforcement with vividly

marked enforcement vehicles; lane control systems which are operated in real-time to

balance variable traffic demands in the merging areas of major joining routes; and the

ability to respond to freeway incidents quickly.

Overall, the team found the use of telematics or ITS solutions more readily accepted

by European engineers and departments than in the United States. In Sweden, for

example, the engineers integrate an ITS solution directly into their operations and do

not call special attention to its use. They find that when they include it as a regular

traffic engineering tool, these approaches are less likely to be questioned for

budgetary or other non-technical reasons. They essentially have embraced telematic

solutions for enhancing both safety and operations.
7

CHAPTER 1

And one of the greatest engineering contrasts between European countries and the

United States is the integration of the different modes of transportation.

Transportation is designed as an integrated system made up of different modes for

the purpose of serving the traveler–the customer. In the United States, while we are

doing more of this today than we did 20 years ago, we are no where near the level of

modal integration found in any of the four countries visited.
8

CHAPTER 1
9

Chapter Two

TRAFFIC CONTROL DEVICES

During their trip to the four European countries, the team members found many

traffic engineering practices that were different from equivalent U.S. practices.

Among the most obvious and visible were the system of traffic control devices used in

Europe. There is a significant amount of uniformity among traffic control devices used

in the four European countries visited by the team.

The team members observed two traffic control device system practices that they felt

may have implementation value in the United States. These items include all-white

pavement markings and the tiger tail freeway entrance ramp markings. They are

described in the Primary Findings section. The team also observed many other

practices which are worth noting to U.S. practitioners. These practices are described

in the Other Observations section and are classified as signs, markings, signals,

pedestrian treatments, and work zones.

PRIMARY FINDINGS

With respect to the traffic control devices, the team members identified two pavement

marking practices that they recommend for evaluation in the United States: “tiger

tail” markings for freeway entrance and exit ramps and an all-white system of

pavement markings.

Tiger Tail

In England, the team found that the Highways Agency has created a special

pavement marking pattern for freeway entrance and exit ramps.(1) This marking,

known as the “tiger tail” or “anti-swooping” marking, separates two entrance ramp

lanes by using a wide painted buffer between the two lanes. As a result, the merge

location for each lane is separated, as is the turbulence due to the two entering

maneuvers. Although this treatment requires a wider and longer entrance ramp than

a side-by-side, two-lane ramp, it increases capacity and reduces conflicts. Figure 3

illustrates several applications of tiger tail markings on entrance ramps in England.

Tiger tail markings have also been implemented on freeway exit ramps in England.

Evaluations of these markings have found they result in smoother traffic flow, less

driver stress, and increased exit capacity, all due to a decrease in the number of

erratic gore maneuvers. Figure 4 illustrates a before and after photo of exit ramp

markings.
10

CHAPTER 2

Figure 3. Tiger tail pavement markings on entrance ramps to English freeways.

Figure 4. Before-and-after application of tiger tail marking on exit ramp. Reprinted with permission from the Highways Agency, UK.
11

CHAPTER 2

All-White Pavement Markings

One of the most striking differences between the United States and the four

European countries is the lack of yellow pavement markings for centerline and left

edgelines in Europe. Each of the countries visited used a primarily all-white system of

pavement markings, including applications for separating opposing traffic. While

other colors were used on a limited basis, the team found considerable advantages in

how white markings were used.

In Europe, white lines are used to separate opposing directions of traffic. However,

individual application and meaning were not totally consistent between the countries.

Some of the white centerline applications included a double white line, a single white

line, and a single wide broken line. Differences in stripe/gap ratios were also observed

between centerlines and lane lines. In France, the team also observed that short skip

lines were used to mark the end of a no passing zone. The short skip lines were

complemented with small curved arrows which directed passers to return to their

side of the road. Figures 5 through 22 illustrate various applications of white

pavement markings.

Other applications of white pavement markings we observed include:

• The separation of traffic lanes in the same direction.

• Use of dotted edge line carried across entrance and exit ramp (see figures 8,

11, 20)

• Double-lines for parking prohibition.

• Parking spaces.

• Marking of pedestrian crosswalks.

• Island designation.

• The marking of lane lines through intersection (the intersection of the lane

lines appear as + symbols in figure 22).

• Short and closely spaced dashed lanes to show how the main motorway lanes

are carried through the interchange and separated from the beginning of the

on-ramp lane and end of the off-ramp.

The team found that yellow marking applications were used on a limited basis. In

work zones in France and Germany, yellow markings are used to indicate travel

paths. The yellow markings are placed on top of the white markings, which are not

removed during the work zone activity. Figures 23 through 25 illustrate this use of

yellow markings. In London, a yellow crosshatch within the intersection indicates

where vehicles are not permitted to queue. This is shown in figure 26. Yellow

markings are also used to denote curbside parking restrictions.
12

CHAPTER 2

Figure 5. Edge line in Lundby Tunnel, Sweden. Figure 6. Airport markings near Frankfurt, Germany.

Figure 7. Intersection markings, France. Figure 8. Markings on rural freeway, France. (Note

edge line marking carried across ramp.)

Figure 9. Markings on freeway exit ramp, France. Figure 10. Markings on rural freeway, France.
13

CHAPTER 2

Figure 11. Markings for exit ramp on rural freeway,

France. (Note edge line marking carried across ramp.)

Figure 12. Markings for rural highway, France.

Figure 13. Markings for rural intersection, France. Figure 14. Markings on rural freeway, France.

Figure 15. Markings for rural highway, France. Figure 16. Demarcation of passing/no passing zone,

France.
14

CHAPTER 2

Figure 17. Photo 1 – Approach to rural intersection with

no passing zone, France.

Figure 18. Photo 2 – Approach to rural intersection

with no passing zone, France.

Figure 19. Photo 3 – Approach to rural intersection

with no passing zone, France.

Figure 20. Photo 4 – Approach to rural intersection

with no passing zone, France.

Figure 21. Approach to rural intersection with

countdown markers, England.

Figure 22. Lane line extensions carried through

intersection (both directions), Germany.
15

CHAPTER 2

OTHER OBSERVATIONS

In addition to the Primary Findings described above, the team members identified

many other traffic control device practices that U.S. practitioners might be interested

in learning about. These are described in the following pages within five major

categories: signs, markings, pedestrian treatments, work zone visibility, and rotary

intersections as shown in table 3.

Signs

There are significant differences in the signing systems of the United States and

Europe. Round white signs with a red border indicate a prohibition or a mandatory

action. Round blue signs with a white legend indicate a mandatory requirement.

Warning signs are white triangles with a red border. Freeway (motorway) guide signs

are typically blue, while guide signs for conventional highways are typically green.

There are some variations in the use of color in the guide signs in different countries.

Figure 23. Yellow markings in work zone, Germany. Figure 24. Yellow markings in work zone, Germany.

Figure 25. Yellow markings in work zone, Germany. Figure 26. Crosshatch in intersection, England.
16

CHAPTER 2

One basic difference in the systems between the four countries is that Sweden uses

yellow instead of white in its prohibitive, mandatory, and warning signs.

Countdown Markers for Exit Ramps

In all four countries, countdown markers are used in advance of exit ramps to inform

road users of the presence of and distance to the exit. The first panel observed was

placed 300 meters in advance of the exit, was set in the shoulder, and had three

closely spaced white diagonal stripes. The second panel was placed 200 meters in

advance of the exit, was set in the shoulder, and had two closely spaced white

diagonal stripes. The third (and last) panel was placed 100 meters in advance of the

exit, was set in the shoulder, and had one white diagonal stripe. In some countries,

the distances (300 m, 200 m, and 100 m) were also shown within the marker. In

England, the markers were placed at 300, 200, and 100 yards from the ramp. These

markers seem to give the road user a more comfortable feeling about the location of

the next exit. On freeways, the markers used white lines on a blue background.

Figure 27 illustrates the use of countdown markers on a German freeway. The vertical

panels along the edge of the travelway are not related to the countdown markers.

Signs

Markings

Pedestrian Treatments

Work Zone Visibility

Rotary Intersections

MAJOR CATEGORIES TRAFFIC CONTROL OBSERVATION PAGE

Countdown Markers for Exit Ramps

More Intensive Sign Colors

Arrowhead Shaped Destination Signs

Internally Illuminated Signs

Use of Dotted Border for Trailblazing

Guide Sign Sheeting Types

Variations in Alphabet Stroke Width

Freeway Exit Direction Signs

Horizontal Signing

Chevrons for Vehicle Spacing

Colored Pavements

Raised Crosswalks

Flashing Yellow on Pedestrian Clearance

Audible Pedestrian Signals

Advance Pedestrian Pavement Markings

Worker Visibility Enhancements

Vehicle Visibility Enhancements

Work Zone Traffic Control

Table 3. Other observations for traffic control devices.

16

18

19

20

20

20

21

22

24

26

27

27

28

29

29

29

30

30

33
17

CHAPTER 2

Figure 27. Countdown markers for exit ramp,

Germany.
18

CHAPTER 2

More Intensive Sign Colors

In observing the traffic signs in the four countries, the team members felt that some

of the sign colors appeared to be more intense than those used in the United States.

Figure 28 compares the xy color boxes from the most common U.S. sign sheeting

standard with one of the European standards.(2,3) As this figure shows, the European

boxes are tighter than the U.S. boxes and there is greater separation between the

colors in the yellow-orange-red portion of the spectrum. Another sign color difference

is that England uses a darker green (referred to as “Worboy green”) for its guide

signs.

Figure 28. Comparison of xy color plots for U.S. and Europe.
19

CHAPTER 2

Figure 29. Arrow shaped sign at exit ramp gore,

Germany.

Figure 30. Arrow shaped sign, England.

Figure 31. Arrow shaped signs at rotary intersection,

France.

Figure 32. Arrow shaped signs mounted on

backboard, England.

Arrowhead Shaped Destination Signs

Throughout Europe, team members observed directional signs that use an arrow

shape to emphasize the directional information presented in the sign. The signs are a

rectangular shape, with an arrow point much like the end of a crayon, and point in

the direction of the destination named on the sign. These arrow shaped signs were

observed in single and stacked installations. The primary effect of these signs is that

they may give more advanced recognition of the direction of the destination than

provided by a true rectangular sign.
20

CHAPTER 2

Figure 35. Use of parenthesis (for A41) in pavement

markings, England.

Internal Sign Illumination

In all four countries, extensive use is made

of internally illuminated regulatory,

warning, and guide signs on conventional

roads and streets in urban areas. These

types of signs provide excellent target

value at night, especially when ambient

commercial lighting and advertising signs

compete for drivers’ attention. The team

members found these signs to be effective

in increasing the conspicuity of the signs

and messages. Due to the high costs and

electrical energy consumption, some of the

countries are considering reducing the use

of internal illumination in favor of brighter

retroreflective sheeting.

Use of Dotted Border for Trailblazing

The team observed several locations where

dotted borders or parenthesis were used

with a route number to indicate a road that

connects to the indicated route (a TO or

trailblazer message). The practice is

usually applied at freeway exit lanes. The

benefit of this practice is that it deemphasizes the number of the connector

route in order to emphasize the route of

greater importance. In England, a

parenthesis is used to indicate the same

TO message. Figures 33 through 35

illustrate the application of this practice in

signs and pavement markings.

Guide Sign Sheeting Types

In Germany, the team members had some

extended discussion with their hosts about

the use of retroreflective material in guide

signs. The current German practice is to

use a high intensity legend on a high

intensity background for ground-mounted

signs. Overhead signs currently use a high

intensity legend on an engineering grade

background with sign illumination.

For their ground-mounted guide signs, the

Germans are changing to an engineering

grade background, while keeping high

Figure 33. Use of dotted border (for E45) in sign,

Sweden.

Figure 34. Use of parenthesis in sign, England.
21

CHAPTER 2

intensity as the legend material. One of the factors supporting the change is that they

feel this will result in an immediate and long-term cost savings. More importantly

though, their research indicates that, due to a better contrast ratio, the legibility of

ground-mounted signs is improved by using a high intensity legend on an engineering

grade background.

For the overhead guide signs, the Germans are eliminating sign illumination and

using super high intensity microprismatic sheeting (Diamond GradeTM) for both the

legend and background. Their research indicates that the legibility of their overhead

signs will not be compromised, even with the low cut-off of European vehicle

headlights. A key factor supporting this change is the continual need for maintenance

and the operational costs of the sign lighting used with their current overhead guide

signs.

Variations in Alphabet Stroke Width

Throughout their travels, the team members found that countries use sign alphabets

that are different from those used in the U.S. While there appears to be some

differences between the alphabets used in each country, the alphabet used in England

appears fairly typical of those observed in each country.

The MUTCD equivalent in England is The Traffic Signs Regulations and General

Directions document.(4) This document identifies two primary alphabets for highways

signs, one for positive contrast signs (light legend on a dark background) and one for

negative contrast signs (dark legend on a light background). A separate document

refers to these alphabets as the Transport Medium alphabet for positive contrast

signs and the Transport Bold alphabet for negative contrast signs. There are also two

other alphabets that are used on a more limited basis: Motorway White for white

legend on a blue background and Motorway Black for black legend on a yellow

background. Both of these alphabets consist of numbers and a limited number of

letters (mostly compass directions).

The interesting aspect of the British alphabets is that the Transport Medium

alphabet (for white letter on a green, blue, brown, or black background) has a

narrower stroke width than the Transport Bold alphabet (for a black letter on a white

or yellow background). It should be noted that the green in British guide signs is

much darker than the green in U.S. guide signs. Since the performance characteristics

of positive and negative contrast signs are different, the use of different alphabets for

each is logical and is a feature absent from U.S. signs. Table 4 compares key letters

from these two alphabets to the U.S. Series E (Modified) alphabet.

Table 4. Comparison of British and U.S. alphabets.

U.S. SERIES E (MODIFIED) BRITISH TRANSPORT HEAVY BRITISH TRANSPORT MEDIUM
22

CHAPTER 2

Freeway Exit Direction Signs

As they traveled on the freeways in each country, the team members observed several

different designs and layouts in freeway guide signs. In general, these signs are blue.

Ground-mounted signs were mostly, but not always, vertical rectangles, while

overhead signs were horizontal rectangles. These signs often used a combination of

word legends and diagrammatic arrows to indicate directional information to the road

user. Figures 36 through 44 illustrate several different applications of freeway exit

direction signs.

Figure 36. Freeway exit direction sign, Sweden. Figure 37. Freeway exit direction sign, Sweden.

Figure 38. Freeway exit direction sign, Germany. Figure 39. Freeway exit direction sign, Germany.
23

CHAPTER 2

Figure 40. Freeway exit direction sign, Germany. Figure 41. Freeway exit direction sign, France.

Figure 42. Freeway exit direction sign, France. Figure 43. Freeway exit direction sign, England.

(Note countdown marker)

Figure 44. Freeway exit direction sign, England.

(Note lane control signals over right two lanes)
24

CHAPTER 2

Markings

In addition to the pavement marking aspects of the Primary Findings described at

the beginning of this chapter, team members were impressed by many other

pavement marking applications that are not used in the United States. These include

horizontal signing (essentially specialized pavement markings), colored pavements,

and chevron markings for vehicle spacing.

Horizontal Signing

The team members found that all of the countries visited use pavement markings to

provide or enhance a wide variety of information for road users. These markings can

take the form of symbols or words on the pavement. This information often

supplements information presented in other types of traffic control devices. This

practice is known as horizontal signing, and European traffic engineers feel very

strongly that the redundancy provided by horizontal signing applications is a very

important element of attaining and improving both efficiency and safety for road

users. England uses this concept quite liberally in addition to providing redundant or

dual messages in many warning and regulatory sign applications. The team members

observed that the European practice of horizontal signing provides road users with a

significantly greater amount of information than is provided by pavement markings

in the United States. In addition, the information provided by pavement markings is

always directly in the driver’s line-of-sight, which is a safety benefit. This is

particularly useful to drivers in moderate to heavy traffic.

Some of the most prominent examples of the horizontal signing that the team

observed are listed below. Figures 45 through 54 illustrate a few of these applications.

Many horizontal signing applications are also illustrated in other figures in this

chapter.

• Highway numbers, with arrows where necessary, at intersections and on offramps leading to the highways where two or more highways converge/diverge.

• Stop and Yield markings on the approaches to intersections, roundabouts, and

pedestrian crossings.

• Markings indicating traffic or parking prohibitions.

• Bus lane markings.

• School markings.

• Lane markings carried through intersections.

• Dotted edge lines through exit and entrance ramps at interchanges. This

concept was universal in all the countries visited, and often the markings were

wider than the normal edgeline.
25

CHAPTER 2

Figure 45. Highway numbers in lanes, England. Figure 46. Highway numbers in lanes, England.

Figure 47. Highway numbers and destination names

in lanes, England.

Figure 48. Stop marking, England.

Figure 49. Yield pavement markings, Sweden. Figure 50. Bus lane marking, Sweden.
26

CHAPTER 2

Chevrons for Vehicle Spacing

In England, transportation officials have

placed chevron markings in traffic lanes to

indicate the proper spacing between

vehicles. The chevrons are placed 40

meters apart. The sign shown in Figure 55

informs drivers to keep two chevrons

between them and the vehicle in front.

Evaluations found the following benefits:

• A reduction of about 15 percent of

drivers “close-following.”

• Fewer accidents as driver

awareness increased over the site.

Figure 51. Intersection directional and crossing

markings, Sweden.

Figure 52. Intersection marking, England.

Figure 53. Bike marking, France. Figure 54. Abbreviated markings carried through

intersection, Germany.

Figure 55. Chevron marking sign, England.

Reprinted with permission from the Highways Agency, UK.
27

CHAPTER 2

• Fifty-six percent fewer injury accidents.

• Eighty-nine percent fewer single vehicle accidents.

• Forty percent fewer multiple vehicle accidents.

• $1.2 million accident savings (1993 prices).

• The effect can last at least 18 km.

• Benefits are 80 times the installation cost.

Colored Pavements

Pavement surface coloring was observed in France and England to indicate lanes for

specific classes of vehicles. In London, a red pavement surface was used to indicate a

bus only lane. In France, a light green marking was used to indicate where a bike

lane intersected with a traffic lane at a rotary intersection. These applications are

illustrated in figures 56 and 57.

Pedestrian Treatments

Throughout the four countries visited, the team members observed much higher

degree of pedestrian traffic than is found in equivalent U.S. situations. In part, this

can be attributed to the greater use of public transportation in Europe than in the

United States, and the resulting pedestrian traffic from the public transportation stop

to the destination. The European countries have developed several interesting

treatments for addressing pedestrian-vehicle conflicts.

Raised Crosswalks

In all four countries visited, raised crosswalks were observed at various locations, in

residential areas as well as commercial districts. A raised crosswalk is basically a

flat-top style speed hump with a marked crosswalk on the plateau portion of the

hump. Figure 58 illustrates a raised crosswalk in Gothenburg. The purpose of a raised

crosswalk is three-fold: to enhance the visibility of the crosswalk (and pedestrians

Figure 56. Bus lane colored pavement, England. Figure 57. Green pavement where bike lane

intersects vehicle lane, France.
28

CHAPTER 2

who are crossing), to reduce the speed of vehicles as they approach the crosswalk, and

to increase the chances of an approaching driver deciding to stop for a pedestrian in

the crosswalk.

The safety improvement for pedestrians,

especially at mid-block crosswalks, is

impressive. A City of Gothenburg

publication indicates that, “At a normal

crossing, only about 8 percent of the drivers

stop for a waiting pedestrian. This figure is

around 30 percent at raised crosswalks. The

far stronger tendency of drivers to stop at

raised crosswalks is related to their having

slowed down so much before the hump

anyway. Then the loss of speed and time feels

less bothersome when they stop [for the

pedestrian]. And the lower speed means that

the driver and pedestrians have more

mutual contact, so it becomes embarrassing

to drive past as if nothing were happening.

Lower speed is the most effective measure to

prevent accidents. If a pedestrian is run over at 50 km/hr (30 mph) the risk of death is

50 percent. But if the driver keeps to 30 km/hr (18 mph) the risk decreases to around 5

percent.” (5)

Flashing Yellow on Pedestrian Clearance

At some mid-block signalized pedestrian crossings in England, an unusual signal

operation and display is used to reduce vehicular delays. For the pedestrian, the

operation is no different than a standard mid-block pedestrian signal in that the

pedestrian pushes the button, waits for the “walk” signal to be displayed, and crosses

the street while the “walk” and its associated pedestrian clearance interval are timed.

In the normal mid-block pedestrian signal operation, traffic on the street has a

circular red signal display throughout the time that the pedestrian “walk” and

pedestrian clearance intervals are being provided. In this unusual operation in

England, the normal operation and display for traffic on the street is modified. A

circular red is displayed to traffic on the street during the “walk” interval but then it

changes to a flashing yellow display during the pedestrian clearance interval. Green

is displayed upon conclusion of the pedestrian clearance interval.

The advantage of this operation is that it reduces unnecessary delays by allowing

vehicular traffic to legally proceed (with caution) on the flashing yellow when there is

no conflict with pedestrians. This occurs when:

• All pedestrians crossing in a given cycle are crossing in only one direction

across the road. After they have crossed halfway, there is no conflict with

traffic that will be driving over the half of the crosswalk they are no longer

occupying, so traffic in that one direction can proceed.

Figure 58. Raised crosswalk, Sweden.
29

CHAPTER 2

• If the pedestrians crossing in any given signal cycle are fast walkers or they

have run across the road, vehicular traffic does not have to wait on red while

the unnecessarily long (in this case) pedestrian clearance interval times out.

The disadvantage of this operation is that overly aggressive drivers may start to move

too soon or may have “close calls” with pedestrians who may not have completely

finished crossing.

Audible Pedestrian Signals

In some cities in Europe, there are combination sight and sound indications provided

at crosswalks. These combined visual and audible indications let pedestrians know

when to walk in the crosswalk and give consideration to both visual and hearing

impaired individuals. Different sounds are used in the different countries.

Advance Pedestrian Pavement Markings

In England, the team members observed a

unique means of informing drivers that

they are approaching a pedestrian crossing.

These zig-zag markings, shown in figure 59,

provide more warning of the crosswalk than

do the crosswalk markings alone.

Work Zone Visibility

During their travels between countries and

between meeting locations within the

countries, the team members passed

through and observed several work zones.

Work zone issues were also the subject of

some discussions with the hosts. In general,

the team observed that Europeans use few

traffic control devices in work zones, but

that they employ several visibility enhancing treatments. These treatments include

worker visibility enhancements, vehicle visibility enhancements, and work zone

traffic control devices.

One of the most noticeable differences with the United States is the lack of orange. In

Europe, yellow is used for work zone signing and markings. The use of yellow for work

zone pavement markings in Germany and France is discussed and illustrated in the

“all-white” section of this chapter (see page 11).

Worker Visibility Enhancements

In their travels and discussions, the team members found that the transportation

agencies visited have made significant strides toward increasing the visibility of

workers, vehicles, and devices in work zones. Worker visibility was strongly

emphasized. Team members learned that Swedish law requires anyone working on a

road to wear a high visibility vest or jacket. Violators can be cited and fined by the

police. Furthermore, their high visibility clothing is more visible than the orange vest

typically used in the United States. Figure 60 illustrates one of these garments, which

Figure 59. Markings on approach to pedestrian

crossing, England.
30

CHAPTER 2

is strong yellow-green in the torso area, orange in the

sleeves and sides, and dark blue on the shoulders. There

are also silver retroreflective stripes around the sleeves

and torso. This combination of high visibility colors

ensures that a worker will stand out against any color of

background. In the other countries, high visibility vests

tended to be predominately strong yellow-green, as

shown in figure 61.

Vehicle Visibility Enhancements

The team found that many of the transportation

agencies place significant emphasis on the visibility of

work zone and maintenance vehicles. Figures 63

through 65 illustrate several of these visibility

enhancing vehicle treatments. Although not technically

a work zone or maintenance vehicle, the team also

observed that police vehicles are also treated to increase

their visibility. These vehicles are often used in

conjunction with work zone/maintenance vehicles in

responding to an incident. Figures 66 through 68

illustrate examples of police vehicles.

Work Zone Traffic Control

In their observations of work zone traffic control, the

team found that the Europeans do not typically use

advance traffic control to the same extent as used in the

United States. However, many of the devices within the

work zone itself utilize visibility enhancing treatments.

Figure 60. Worker vest, Sweden.

Figure 61. Worker vests, France.

Figure 62. Maintenance vehicle, Sweden.
31

CHAPTER 2

Figure 63. Maintenance vehicle and trailer, France. Figure 64. Incident response vehicle, France.

Figure 65. Work zone vehicle, France. Figure 66. Police vehicle, England.

Figure 67. Police and incident response vehicles,

England.

Figure 68. Incident response vehicle, England.
32

CHAPTER 2

Figure 69. Photo 1, Advance work zone, France. Figure 70. Photo 2, Channelizing transition

to work zone, France.

Figures 69 through 71 illustrate the approach to a work zone in France. The initial

advance sign (figure 69) is yellow with red at the top. The legend in the red portion is

“Attention/Travaux.” The main legend indicates the travel path through the work

zone. This sign is located 200 m in advance, and is repeated at 100 m. Near the work

zone, yellow pavement markings (figure 70) provide channelizing guidance for traffic.

In this situation, the normal white markings have been removed, in comparison to

figures 23 to 25, where the white markings were not removed when the yellow work

zone markings were installed. The red and white work zone barriers are visible in the

background of this figure. At the work zone (figure 71), the barriers are alternating

red and white, with red/white chevron-type devices above the barriers. There are also

two flashing warning lights within each of these chevron-type devices.

Other treatments are also used to increase the visibility and/or conspicuity of devices

in the work zone. Figure 72 shows two cones in England. The area of retroreflective

sleeve on these cones is significantly larger than is used on cones in the United

States.

To highlight the location of a traffic lane modification in a work zone, strobe lights are

located on top of signs which indicate the change in travel path. Figures 73 and 74

illustrate two applications of strobe lights. Figure 73 also illustrates how the

European agencies use colors and patterns in a backboard to increase the conspicuity

of the main message in work zone signs.
33

CHAPTER 2

Figure 71. Photo 3, Work zone protection, France. Figure 72. Retroreflective area on cones, England.

Figure 73. Strobe lights above work zone signs,

Sweden. (Note strobe lights on for left sign

and off for right sign)

Figure 74. Strobe light above temporary gore sign,

Germany.

Figure 75. Rotary intersection, France.

Rotary Intersections

The team members also observed numerous

rotary intersections as they traveled through

the four countries. Although the team did not

develop any recommendations regarding

traffic control at rotary intersections, they felt

that U.S. practitioners might be interested in

seeing some of these practices. Figures 75

through 81 illustrate various applications of

markings and signing for rotary intersections.
34

CHAPTER 2

Figure 77. Rotary intersection, France.

Figure 78. Rotary intersection, France. Figure 79. Rotary intersection, England.

Figure 80. Rotary intersection, England. Figure 81. Rotary intersection, Sweden.

Figure 76. Rotary intersection, France.
35

Chapter Three

FREEWAY CONTROL

The FHWA team observed many different freeway facilities during their travels

through Europe. In Europe, these facilities are known as motorways. Many of these

facilities are operating very near capacity levels, and demand exceeds capacity in

some locations. The team found that the operating agencies have developed several

practices for optimizing freeway operations.

PRIMARY FINDINGS

The team found that the four European countries visited have developed

sophisticated methods of controlling vehicular flow in freeway lanes and providing

freeway users with information that helps optimize freeway operations. Among the

key features that the team members observed in the various countries are variable

speed control, incident/queue detection, queue protection, and lane reduction controls.

Variable Speed Control

In Sweden, Germany, and

England, the transportation

authorities were able to

achieve considerable traffic

flow and safety benefits on

freeways by dynamically

changing the speed limit

based upon real-time traffic

speed and flow data.

Sudden disturbances in

traffic flow are detected by

loop sensors and

appropriate reduced speed

limit messages are

displayed to approaching

traffic (well in advance of

the queue or disturbance)

by variable message signs.

The speed limits consist of a red circle with a white number inside the circle and

typically use light emitting diodes. These speed limits are regulatory and are

enforceable. Figures 82 through 85 present various examples of variable speed limit

displays. In all cases, the variable speed limit is displayed as a number within a red

circle. As such, its appearance is the same as the standard European speed limit sign

(illustrated in figure 86). Figure 87 provides a close-up view of one of these

indications. Each of the upper corners in this photo contains two flashing warning

lights that activate when the speed limit has been lowered. These variable speed

control practices are closely integrated with the queue and incident detection

Figure 82. Variable speed control, England.

Reprinted with permission from the Highways Agency, UK.
36

CHAPTER 3

technologies, described later in this chapter,

to reduce the incidence of secondary

accidents (rear-end at start of queued

traffic).

The team members learned of two key

elements to the success of the variable speed

limits. One is the accuracy of the indicated

speed limit. For drivers to respect and

comply with the indicated speed limit, they

have to recognize the accuracy of the

message. The second key element was

automated enforcement of the variable

speed limits (see page 35). The team

Figure 83. Variable speed limits, England. Figure 84. Variable speed limit, England.

Figure 85. Variable speed limits, Germany. Figure 86. Standard speed limit sign, France.

Figure 87.

Close-up of

variable speed

limit indication,

England. (Note

flashing

warning lights

in corners)
37

CHAPTER 3

members feel that the ability to adjust the regulatory speed limits on freeway

facilities is a critical element of achieving significant operational benefits from the

system. It is also a capability which is not currently available in the United States.

Lane Control Signals

In addition to the variable speed limits, the team observed that lane control signals

are widely used to control traffic on freeways. The most common use of these signals

is to indicate lane closures for incident management and maintenance activities as

part of real-time “controlled motorway” systems. Such signals are also used in the

United States, but are not nearly as extensively as in Europe. The display concepts

used in Europe to indicate an impending freeway lane closure are also slightly

different from those in current use in the United States. The sequence of indications

used in these signals is different from that used in the United States. The initial

indication of a closed lane is a downward diagonal yellow arrow pointing toward the

lane that road users should move to. This is followed downstream by a red X.

The team members learned of an innovative use of lane control signals in Germany.

The signals were used where two freeway mainlines or entrance ramps merge, but

the number of downstream lanes is less than the sum of upstream lanes. The

traditional treatment for this situation would be a lane drop for one of the outside

lanes or a merge of two inside lanes. Either treatment is static (i.e., in effect 24 hours

a day) and would typically be imposed on the upstream roadway that carries a lower

volume. This static control does not allow for changes in control based on changes in

relative volume of the approaches in different periods of the day. The dynamic

solution utilized by German officials is to install lane control signals over both

upstream approaches well in advance of the merge, and operate them with variable

displays at different times of the day. During any given time period, the approach

with the higher volume is provided with signals indicating all lanes open, while a

lane closure is displayed for the lesser-volume approach. As the relative volumes of

the two approaches change throughout the day, the lane closure is switched from one

approach to the other as needed. This dynamic system (which can be operated on a

pre-scheduled basis or a real-time basis

using detectors) makes the most efficient

use of the available roadway infrastructure,

as well as improving safety by imposing the

lane reduction at a place where drivers do

not have to contend with other lane changes

associated with the merge of two roadways.

It could be used on a permanent basis or as

an interim solution until the downstream

roadway can be widened. Figure 88

illustrates the use of a red X and green

arrow in lane control signals.

Team members also observed the use of lane

control signals in England on a seven-lane

section of freeway with no median. The use

of lane control signals allowed the capacity

Figure 88. Lane control signals, Germany.
38

CHAPTER 3

of the freeway to be adjusted to balance the demand. Figure 89 illustrates this

application in Birmingham, England.

Incident and Queue Detection and Protection

Freeway queue detection and protection is an innovative real-time traffic control

technique utilized in all four countries. It has documented benefits in accident

reduction and travel time reduction and has potential for U.S. implementation. It

involves instrumenting stretches of freeway with traffic detection equipment for

determining characteristics of traffic queues as they begin. Armed with that

information, the operating authority

then alerts traffic approaching the

back of the queue so that speeds are

reduced and rear-end accidents are

reduced. The systems vary in

technology up to fully automated

ones that involve variable speed

limits, lane control signals, and

variable message signs that slow

traffic upstream of the queue. In

some locations, incident response

vehicles provide additional protection

with flashing lights or variable

message signs that trail the back of

the queue from the shoulder(s). As

the queue grows longer, the incident

response vehicles back up on the

shoulder, always positioning

themselves as advance warning of the queue.

Sweden utilizes a traffic management system of detection, lane control signs, variable

speed signs, and variable message signs called Motorway Traffic Management (MTM).

In Gothenberg, it is used in the Lundby Tunnel, where it utilizes loop detectors and

video camera detection. The system is able to measure volumes and speeds; classify

vehicles; and detect incidents, “ghost drivers” (wrong-way vehicles), disabled vehicles,

and pedestrians. It utilizes individual lane control signals to provide smooth

transitions for lane closures. It also utilizes variable speed limit signs to control

speeds. Variable message signs provide relevant information to approaching

motorists.

The benefits of these freeway queue protection systems have been fairly well

documented. In Sweden, the team learned that the Motorway Traffic Management

(MTM) system being used in the Lundy Tunnel and planned for other sections of

Swedish freeways is the same as the system demonstrated in Amsterdam. That

system resulted in a decrease in overall accident rates of 23 percent, reduction of

serious accidents of 35 percent and secondary accidents of 46 percent. On a stretch of

the German A5 autobahn between Bad Homburg and Frankfurt/West using variable

speeds and lane control signals, accident rates fell by 20 percent. On a comparable

section of autobahn without control, accidents increased by 10 percent in the same

Figure 89. Lane control signals on freeway with no

median, England.
39

CHAPTER 3

time period. The financial calculations of the reduction in serious and injury accidents

of 29 percent on the A5 in Germany equated to an annual savings of approximately 7

million DeutschMarks ($4 million U.S.) annually. Secondary accidents (resulting from

traffic disturbances) were decreased by two-thirds. The Germans estimate that the

payback in savings from the reduced accidents equals the cost of the systems in 2 to 3

years. Additional benefits cited by the Germans are reduced travel times, decreased

fuel consumption, and lower exhaust emissions.(6)

Motorway Incident Detection and Automated Signaling (MIDAS) is a system used in

England for automated control of speed limits. It is a typical incident detection and

traffic data collection system. MIDAS uses loops located at 500-meter intervals in all

lanes. Roadside processors (outstations) analyze the data to detect queues and slow

moving traffic resulting from freeway incidents or capacity constraints. When an

outstation detects a queue or other specified condition, it sends an alert to the

appropriate Police Control Office via the freeway communications network. The

MIDAS “subsystem” assesses the alert and sets the appropriate speed(s) on the

variable speed limit signs. A queue protection feature of MIDAS on the M25 (and

possibly other freeways) uses occupancy and speed control alerts to determine which

speed signals should be set to best manage the traffic and protect the back of the

queue. The system has been shown to be very effective at protecting drivers in

congested queuing traffic. It has proved effective at detecting the queue arising from

an incident or capacity constraints (frequently setting signals several minutes before

police operators), and then tracking the queue as it spreads back from its source,

automatically maintaining protection and freeing police resources to deal with the

incident. In a 2-year study of system performance, it was found that driver

compliance with posted speeds was very high, lane utilization was improved both

laterally (distribution across lanes) and longitudinally (more even headway spacings),

and there were indications that safety had improved. Police records for the first year

showed a reduction of 28 percent in injury accidents and 25 percent in damage-only

accidents, compared with the previous year. Data for the second year indicate that

safety improvements had been maintained. Reaction from the public has been

positive, with a majority of M25 drivers reporting they prefer to drive under

controlled conditions on busy, congested freeways and would support wider use of

controlled freeways.(7)

Immediate Detection of Stopped Vehicles (DIVA) is a system for the automatic

detection of incidents through video processing. The system was developed and used

by a toll road operating company (COFIROUTE) in France.(8) The system uses

cameras installed on high poles along emergency lanes. Each camera covers a stretch

of 100 to 500 meters. They are connected to the toll road operations center via fiberoptic communication lines. Digital image processing tracks pixel movements of

images and generates alarms for specific incident types. Operators can view images

transmitted by the cameras and determine the type of intervention that might be

required. Just 30 seconds elapse from the moment the vehicle stops to the issuance of

the incident-specific alarm. The operating company claims a 99 percent detection rate

with false alarm rate under 1 percent in tunnels (90 percent with 5 percent false

alarms on open highways).
40

CHAPTER 3

OTHER OBSERVATIONS

In addition to the Primary Findings associated with variable speed limits, freeway

lane control signals, and incident/queue detection, the team members observed two

other practices that may be of interest to U.S. practitioners: rolling freeway blocks and

detection systems on the freeway shoulder.

Rolling Freeway Block

In England, instead of waiting approximately an hour, or longer, to remove smaller

debris from the roadway, the police remove the objects by a technique referred to as

the rolling freeway block. In advance of the debris, one or more police vehicles slow

down traffic in the obstructed lane(s) to approximately 20 to 30 mph. An officer on the

passenger side of one vehicle opens the door and picks up the debris while traffic

remains moving. They have found that this technique is very cost-effective as it can be

quickly implemented, requires only minimal staffing, and is generally well accepted

by the public.

Shoulder Detection

Many European countries, England in particular, are establishing as a design

standard the installation on loops on the shoulder in addition to the mainline

locations. This change was prompted by the lower cost at the construction stage and

facilitating traffic monitoring and incident and breakdown detection. This option

should be considered on new construction projects if traffic management is in place or

being considered in the future.
41

Chapter 4

OPERATIONAL PRACTICES

PRIMARY FINDINGS

The team members were extremely impressed by the many advanced operational

practices utilized by the host countries. Each of the host countries has utilized

strategies that help them optimize the operational aspects of their respective systems.

Although impressed by many different practices, the team members identified two

that demonstrate the greatest potential for implementation in the United States:

intelligent speed adaption and self optimizing signal control. Team members also

observed other practices which may have value to U.S. practitioners, including

practices for signal operations, safety, and design features.

Intelligent Speed Adaption

Intelligent Speed Adaption (ISA) consists of processes which monitor the relationship

between a vehicle’s current speed and its suitable speed, and instigate a corrective

action if the relationship is out of balance. If a vehicle is being driven at too high a

speed, a “road beacon” transmits a signal to a receiver in the car. The driver is warned

by a sound or light signal which tells him that he is driving too fast.

Speed adaption systems can also be totally automatic, like the system tested in Eslov,

Sweden. The urban area of Eslov provided a test area where radio beacons at access

points turned on/off a function in test vehicles. When turned on, the speed of the

vehicle was limited to a maximum of 50 km/hr. The driver experienced this speed

limiting activity in the form of resistance in the accelerator and the fact that it was

not possible to increase speed, even if the accelerator was depressed still further.

Interviews of Eslov test drivers indicated clear-cut benefits: the system was regarded

as a safety measure and not as an unpleasant control or source of irritation. Behavior

studies also clearly revealed that the driving behavior of the test drivers improved in

the interplay with other road users.

A large scale ISA field trial will start in 1999 in four cities in Sweden. The budget for

the 2-year test is 75 million SEK (about $10 million U.S.) and approximately 5,000

vehicles will be equipped with ISA. This trial will be conducted primarily in urban

environments with complex traffic situations in which many different groups of road

users interact. The trial will also make it possible to test and develop the interplay

between the major players in the road transport sector.

Some early findings from users in a test in Umea include: 1) the percentage of drivers

who actually comply with a 30 km/hr speed limit increases from just over 20 percent

to just over 80 percent, 2) more than 50 percent say “comfort increases,” 3) 75 percent

feel that the mental pressure is less, 4) almost 100 percent think this will lead to

“safer traffic,” and 5) interaction with other road users improved.
42

CHAPTER 4

Self Optimizing Signal Intersection Control

Traffic engineers in the U.S., particularly those with rural high speed highway

responsibilities, are often faced with operational and or safety problems at traffic

control signal installations. Even with the most sophisticated traffic signal controllers

and detection systems in current use at rural, isolated, high speed installations,

crashes (particularly the rear end type) continue to occur during the change of rightof-way between mainline traffic and the cross street traffic. At rural, high speed

traffic signal installations with high volumes, the risk of rear end collisions increases

significantly.

Sweden, faced with the same operational and safety issues at isolated high speed

traffic signal installations as their U.S. counterparts, has developed an advanced

traffic signal control system to minimize the potential of rear end crashes and red

light running. The system is called SOS for Self Optimizing Signal Control.

Development of the SOS control system began in 1992 with 24-hour field operation of

the system and evaluation beginning in 1995. The SOS control system is an

enhancement of several other European traffic signal control systems, including the

British MOVA and Swedish LHORVA which have been in use for some time. Two

reports describe various aspects of the SOS, MOVA, and LHORVA systems of control. (9, 10)

The SOS control system consists of a typical actuated traffic signal controller

operating in parallel with a microcomputer. The software within the microcomputer

operates the optimization package which can be structured to assess one or all of the

following criteria: safety, delay, emissions, or fuel consumption. The main function of

the SOS strategy is to decide when to end traffic signal phases, similar to the gap

reduction of typical controllers, but in a much more sophisticated manner. The SOS

software optimization within the microcomputer is continually performed between

the moment when a queue gathered at a red/stop condition is discharged and that

moment when all traffic on the approach is stopped. During this time, the SOS

microcomputer software seeks the optimum moment to change from green to yellow.

The controller itself takes care of its typical functions including the green demand,

phase selection, etc.

The optimization function is a difference function that calculates the benefit for an

extension of the present phase compared with stopping the phase immediately. These

benefit calculations are performed two or more times per second. From the

optimization strategies chosen by the traffic engineer, the microcomputer software

develops the benefit calculation in the form of a cost algorithm. The safety component

of the optimization, or incident reduction strategy, assesses the number and position

of vehicles within the dilemma zone, striving to keep the potential risk for a rear end

collision between any two vehicles to a minimum, as shown in figure 90. Optimization

is based on the calculation of one, all, or any combination of delay, emissions, or fuel

consumption costs for vehicles on the cross street, and the potential for delay,

emissions, or fuel consumption for vehicles at any point in time if the mainline would

be stopped. These factors can also be weighted to meet the needs of the traffic

engineer. The SOS can call for the extension of the maximum green time of a phase

that would apply under normal traffic signal controller operation, to a pre-selected
43

CHAPTER 4

time. This system offers significant potential for enhancement of the operation of a

high speed isolated traffic signal installation.

The advantages of the SOS control system include:

• The number of vehicles within the dilemma zone on an approach is kept to a

minimum and the number of vehicles at risk of a rear-end collision at the time

of the change from green to yellow for a change in right of way is kept even

lower. This is made possible by the optimization algorithm and the advanced

incident reduction function in combination.

• By using a mathematical optimizing algorithm, SOS adapts very well to the

instantaneous traffic condition. One key example would be a platoon of

vehicles arriving near the max out of normal signal control. The SOS assesses

the cost impacts of the arrival and potential of stopping that platoon compared

to the costs associated with vehicles queuing on the red. The SOS can extend

the green or terminate it depending on the results of the optimization.

• Left turns in mixed traffic can be helped by an intelligent algorithm giving an

early cut-off of one of the directions of flow. The optimization routine assesses

each direction of travel independently. The early cut-off allows the SOS system

to serve the traffic stream with the biggest need at any moment. This variation

of phasing, which means a lead or lagging left turn phase can come up on an

approach, even in a protected/permitted mode of operation, can be safely

accomplished as described at the end of this discussion.

• The mathematical optimization algorithm makes it possible to change control

strategies according to the needs identified by the traffic engineer. This is

accomplished simply by changing the costs associated with the safety,

emissions, delay or fuel consumption parameters of the optimization model.

Figure 90. Incident reduction signal control strategy. SOS checks the number of vehicles in the

option zone. Single vehicles in a lane have a lower cost than others. SOS also makes a forecast

for the future in order to find the best moment to end green. (Source: Reference 9)

Reprinted with permission from the Swedish National Road Administration.

Dilemma Zone
44

CHAPTER 4

• The SOS allows the user to obtain intersection

performance expressed in monetary terms. This can

be different for different times of the day.

The SOS system does of course have some

disadvantages, including:

• The system requires more detection and more

costly control equipment than the typical actuated

traffic signal installations in use in the United

States, and is not suitable for multi-intersection

coordinated signal systems.

• The model does not work particularly well in

congested conditions. According to the Swedish

authorities, however, this disadvantage can be

overcome with more advanced detection systems

using video or radar tracking giving speed and

vehicle type.

• The present version of the SOS system needs an improved interface between

the microcomputer and the controller to allow more flexibility to use different

types of controllers.

• The algorithms for over-saturated control have not been tested in the field as

yet.

• The SOS control has only been field tested in one location.

To safely accomplish the protected/permitted lead, lag left turn phasing on an

approach at an intersection under the early cut-off described earlier, the Swedish

detection designs use “banana detectors” as shown in figure 91. This type of design

will of course pick up those vehicles who self position themselves beyond the normal

stopping point in the left turn lane to get a clearer view of conflicting traffic. Without

this type of detection, operating in a lead/lag, protected/permitted mode could result

in the “left turn trap” for the turning vehicles when their direction of through traffic

terminates and the opposite direction of through traffic which they are attempting to

turn across continues.

One of the key results the Swedish traffic engineers have found with the SOS control

system is that number of vehicles in the dilemma zone at the time the SOS system

determines to change the right of way, is reduced by 38 percent compared to their

LHORVA system under the same conditions. This means of course, that the potential

to reduce rear end crashes is improved considerably. While there is no direct

comparison with the LHORVA system in the United States, it is very likely that our

typical system of traffic control at high speed, isolated, signalized intersections is no

better or no worse than the Swedish LHORVA which is currently installed at 800

intersections in Sweden. The LHORVA system also has optimizing algorithms, but

not as sophisticated as the SOS system, particularly regarding safety. It could be

expected then that there would be safety gains in the United States by using the SOS

control system at high speed, isolated, traffic control signals.

Figure 91. Banana detectors for left

turning. (Source: Reference 9)

Reprinted with permission from the Swedish National Road Administration.
45

CHAPTER 4

OTHER OBSERVATIONS

In addition to the Primary Findings described above, the team members identified

many operational practices related to signals, safety, and design that represent

innovative traffic control practices.

Signals

The team members found some very sophisticated signal operation strategies among

the countries visited during the trip. Two of the more applicable to U.S. practitioners

are the use of historical loop detector data when a loop fails, and coordinated signal

preemption strategies.

Use of Historical Loop Data During Loop Failure Conditions

As a part of the SOS advanced traffic signal control strategy project in Sweden, the

Swedish National Road Authority (SNRA) has developed advanced signal controller

algorithms to improve signal operation during conditions of vehicle detector failures.

In traditional traffic signal controllers, when a detector fails, a “constant call” is

automatically placed on the signal phase. This results in the actuated signal phase

green being called in every cycle and extending out to the maximum every cycle,

regardless of actual traffic demand on that phase. When aware of a detector failure,

agencies sometimes reduce the maximum green settings for the phase as a temporary

measure until the detector can be repaired or replaced. This “compromise” timing

setting (intended to reduce delay to other traffic in off-peak times resulting from the

failure) nevertheless increases peak-period delay to the phase with the failed detector.

Overall, the detector failure results in significant additional delays to all traffic at the

intersection.

The Swedish algorithm and control strategy addresses this problem very effectively.

During normal operation of the detector, the controller software collects and stores

“historical data” on how much green time is provided to the phase (based on the

actuations) each cycle and averages this data over a predetermined time period (such

as for each hour of the day or each 15-minute period of the day.) When the detector on

that phase fails, instead of just going to a “constant call/maximum green time each

cycle” condition, the controller provides differing amounts of green time for that phase

at different times of the day, based on the historical phase green time data it has

collected. Particularly for intersections with approaches having widely variable traffic

volumes, this control strategy is extremely beneficial in reducing intersection delays

during the detector failure condition.

The SNRA reported that the cost of Swedish controllers is relatively high, due in part

to their capability to perform functions such as this. However, such increased

equipment costs are small when compared to the savings to road users associated

with reduced delays at intersections.

Coordinated Signal Preemption Strategies

In Sweden, transit priority and preemption of signals in urban areas is widely used.

This is a result of political decisions to give transit vehicles blanket priority over
46

CHAPTER 4

private vehicles. However, in Gothenburg, Sweden, the political leadership has come

to recognize that providing such an over-riding priority to transit vehicles has

eliminated the benefits that coordinated traffic signal systems would otherwise

provide along urban arterials and in urban grid systems. The very frequent signal

preemptions (currently an average of 4 preemptions every 10 minutes at typical

downtown intersections, projected to grow to 12 every 10 minutes as the tram system

expands) causes extreme disruption to progression patterns between signalized

intersections and has resulted in serious “gridlock” conditions. In response, local

politicians asked traffic engineers to develop a system that would give transit priority

without causing as much disruption to private vehicle travel.

The “SPOT” system, which was developed to address these concerns, incorporates the

following features:

• Priorities for preemption are weighted in terms of relative need versus

disruption. An emergency vehicle is considered the equivalent of 2000 nonemergency private vehicles, a tram or bus that is behind schedule equals 500

vehicles, while a tram or bus that is on schedule is equal to one private vehicle

(and thus in essence receives no priority.)

• Queue lengths are monitored on all links in the grid. If the queue exceeds 80

percent of the link length, it is considered “at risk” for backing into the next

signalized intersection and the control strategy is adjusted to reduce the

queue.

• Each intersection approach is separately controlled and can be provided with

green or red phases independently of each other. Pairs of approaches (such as

northbound and southbound through) that would ordinarily operate together

on a single common phase are controlled separately so that preemption can be

applied to individual approaches and progression can be established on

individual links between intersections.

• Every 3 seconds the system tries to re-establish “green waves,” not necessarily

on the cycle and offset pattern that was in effect prior to the preemption

occurring. This is claimed to be an advancement over “SCOOT” and other

similar systems.

SPOT has been implemented and evaluated at eight intersections in downtown

Gothenburg and has been found to reduce delays to private vehicles in peak hours by

up to 15 percent, compared to previous conditions with unweighted priority

preemption.

Safety

The team members learned that safety is an inherent consideration in all

transportation related decisions made by the various agencies. The administrative

practices chapter of this report addresses the safety orientation of the agencies in

more detail. However, the team members observed two operational practices that

have a primary safety emphasis that might be of value to U.S. practitioners:

automated speed enforcement and emergency phones.
47

CHAPTER 4

Automated Enforcement

Throughout their trip, the team members observed a

widespread use of automated enforcement. The most

commonly observed application of automated

enforcement was for speed. In this use, enforcement

cameras were observed on several classes of roadways.

Automated enforcement is also used for red light

running.

Officials in England indicated that automated

enforcement of the freeway variable speed limits (see

page 35) was the key to obtaining driver compliance with

the indicated speeds. They used cameras mounted on the

backs of the overhead freeway signs above each lane.

Detectors identify vehicles traveling above the speed

indicated in the variable sign and the cameras take

pictures of the license plate on the back of a vehicle. Laws

were established that set the vehicle owner as being

responsible to either accept the ticket given by the

automatic speed enforcement system or to identify the

driver of the vehicle when it was photographed. This

system has proven to be very beneficial in that it has

caused a very high compliance with the speed limit, a

slight increase (5 to 10 percent) in the roadway capacity,

and a very dramatic decrease (25 to 30 percent) in the

number of rear-end accidents on the approaches to

freeway queues.

These enforcement cameras use flashes to provide the

lighting for the photograph. Officials found that, if the

flashes continue to operate, they only needed to keep

cameras in a relatively small number of the camera

containers. The camera flash alone (operating without a

camera) provides drivers with sufficient indication of

enforcement to ensure compliance. The small number of

cameras were rotated frequently so that motorists would

not know if the flash coming from the camera box meant

a picture was actually taken. Figures 92 and 94 indicate

typical signing that is used with the automated

enforcement cameras.

Figure 92. Variable speed limit sign,

England.

Figure 93. Variable speed limit ends

sign, England.

Figure 94. Enforcement camera sign,

England.
48

CHAPTER 4

Emergency Phones

The team members found widespread use of emergency phones in several of the

countries they visited. In Germany, emergency telephones are located every 2 km on

each side of the autobahn system. Emergency calls at any hour are routed to the

telephone exchange of central road maintenance depots who further arrange for help.

In the case of accidents, calls are relayed to the police. In the case of breakdowns, the

services of the automobile associations are summoned by radio.

In France, freeway emergency telephones are installed every 1, 2, or 4 km depending

on location and type of facility. Emergency telephones are connected with Emergency

Centers via proprietary cable, PTN, or radio. Europe has a standard mobile telephone

number for emergencies (112). In France, 15 is the mobile phone number for medical

aid and ambulances, 17 is the number for police services, and 18 is the number for fire

services.

In England, there are approximately 5,500 existing freeway emergency telephones

linked to the police-run Operations Centers. Normally these are sited in pairs (one for

each direction), at approximately 1.5 km intervals. This means that the nearest

telephone is always within 750 m. Additional telephones are provided along more

busy stretches such as freeway interchanges and in tunnels. This enables the user to

reach a telephone without having to cross a roadway. Telephones are positioned so

that the user is facing the on-coming traffic or, where a crash barrier is installed,

facing the roadway. Inside the telephone housing are step-by-step instructions on how

to use the telephone system. The telephones have inductors in their circuits so they

can be used by a caller wearing a hearing aid; they also display the World Deaf logo

on the housing door. As a further aid to telephone users, marker posts are provided

adjacent to the shoulder, or attached to bridge parapets, at 100-m intervals. Marker

posts bear a telephone handset symbol with an arrow showing the direction of the

nearest freeway telephone. Each post is marked in kilometers and tenths of

kilometers from a normal start point, thus permitting accurate identification of any

location anywhere on the freeway.

The Highways Agency is in the process of redesigning the Emergency Roadside

Telephone (ERT), which it provides on freeways and some trunk roads in England.

Although the present telephones have served well over many years, they are no longer

suited to large scale production. Some improvements in the new phones include:

ergonomic design (everyone knows how to use them), ease of use for short and tall

callers including people in wheelchairs, an ear piece that reduces background noise,

and a better microphone to improve communication.

Design Features

The team members observed many different design features of highways and

roadways in the countries visited. However, very few of these related to the subject of

the scan trip. The one design feature identified by the team for inclusion in this report

is the police patrol bay.
49

CHAPTER 4

Figure 95. Police patrol bay, England.

Elevated Police Patrol Bays

On the freeways in England, the team

members noticed elevated police bays along

the edge of the road. These bays place the

patrol vehicle approximately one meter

higher than the road surface. This provides

personnel in the vehicle with a better view

of the roadway traffic. Figure 95 illustrates

one of these patrol bays.
50

CHAPTER 4
51

Chapter Five

INFORMATION MANAGEMENT

One of the keys to optimizing the efficiency of a transportation system is getting the

right information to the system users at the right time at the right location so that

they can use it to influence travel decisions. In all four of the countries they visited,

the team members found outstanding examples of transportation information

management. Some of the most noteworthy are described in this chapter.

As a result of the existence of multiple languages within relatively small geographical

areas, one of the key components of European information management practices is a

widespread use of symbols. Other important components are the integration of

information from different transportation modes and the use of advanced technologies

for communicating information to users.

Two aspects of information management were identified by the team as Primary

Findings that have potential implementation value in the United States: the display

of travel information and the widespread use of symbols in presenting information.

Team members also observed other information management practices that may be of

interest to U.S. practitioners.

PRIMARY FINDINGS

In Europe, transportation modes function as a complete system, and much of the

information management aspects of the system relate to integrating information from

public transportation, single user vehicles, and other modes. Because of the

significant contrasts between transportation systems in the United States and

Europe, the team members believe that much of the information management

strategies have limited short-term implementation value in the United States. Two

practices that do have value are greater use of symbols in presenting information and

the display of travel information.

Symbolics

Symbols are used extensively throughout the four European countries visited. The

European system of traffic signs is almost exclusively symbol-based. In addition, the

Europeans also employ widespread use of symbols in variable message signs (VMS).

The variable messages fall into the following categories:

• Danger instructions and indications such as speed reduction.

• Lane assignment such as lane closures or shifts.

• Directional information such as route detours.

• Information regarding the reason for delays, such as congestion.

The VMS display regulations require the use of symbols (or pictograms as they are

more commonly termed in Europe) for speed control and lane assignment. These

applications were discussed as Primary Findings in the Freeway Control chapter of

the report. The speed control symbol is used to moderate speeds and help prevent stop
52

CHAPTER 5

and start conditions for smoother flow of traffic. The lane assignment symbol (red X

or green arrow) is particularly helpful when a lane closure situation exists. For all

situations that require action on the part of the driver, symbols are used.

There are times when additional messages may be appropriate for informing the

driver about the particular nature of the incident. Research conducted in Europe has

shown that the drivers’ journeys are less stressful when they are told the reason for

unexpected delays. Figure 96 illustrates several symbols that are commonly used in

variable message signs in Europe.

The European countries also use symbols to inform drivers of detour directions.

Alternative routes are “pre-signed” with geometric shapes in changeable message

signs to define specific alternative routes. Figure 97 illustrates several of these

shapes. When it is necessary to divert traffic from the main road, one geometric shape

is displayed on a guide sign on the main road. In Germany, this was done through the

use of a rotating drum within the sign. The same geometric shape is displayed at all

decision points along the detour route. Figure 98 illustrates the use of a geometric

shape at a decision point along the detour.

When direction, detour routes, or other similar information is necessary, text

messages may be used with the pictograms. The text message length and phrasing

Figure 96. Symbols used in variable message signs.

a. Danger–Warning b. Congestion c. Snow

d. Slippery e. Worker f. Trucks–No Passing
53

CHAPTER 5

rules vary in the four countries. For example, in England the text displays use two

lines with a maximum of 12 characters per line. In France the text displays use only

one line with 10 characters maximum.

This practice of displaying symbols is particularly useful in overcoming language

barriers to international travel and motorist comprehension. Research is underway to

develop additional symbols for inclusion in the European standards for traffic control

devices. Two specific conditions for which symbols are

being explored are “fog” and “accident.”

Display of Travel Time Information

Each country had various systems of displaying travel

information, including the use of variable message signs.

France’s use of variable message signs that incorporated

up-to-date traffic conditions gave an excellent example of

real-time travel time information for motorists around

Paris. Variable message signs have been installed at 204

locations on the Paris ring freeway, its ramps, and the

inner city ring freeway. Figure 99 illustrates one of these

signs. Travel times to upcoming major junctions are

calculated by an algorithm (which has been calibrated and

tested for accuracy), displayed on variable message signs,

and are updated every minute so that real-time data is

provided to the motorists. Flow rate, congestion rate, and

speed are detected by 680 sensors and provide the data

necessary to keep the messages displayed up to date.

Surveys of drivers in the Paris area found that they find

the real-time travel time information much more useful

Figure 97. Diversion symbols.

Figure 98. Detour symbol signs.
54

CHAPTER 5

than general messages such as “congestion

ahead.” A 1994 evaluation of this system

found that 65 percent of the motorists

preferred travel time information over

congestion information.

OTHER OBSERVATIONS

In addition to the Primary Findings, the

team members observed and learned about

many other aspects of European

information management. These practices

address both the visual presentation of

information through signing,

communication of information through the

radio and other auditory mediums, and

private sector involvement in collecting and

distributing transportation information.

Consistency in Variable Message Signs

European systems providing for centrally controlled VMS displays for incident

management and congestion information appear to be farther advanced than U.S.

counterparts in terms of assuring consistency and understandability of the messages

displayed. European standard symbols have been developed for a variety of messages

that, in the United States, would be displayed with text. Also, software systems have

been developed and implemented in several countries to either automatically

generate standardized VMS legends based on the situation detected or to assist

Traffic Management Center (TMC) console operators by checking for consistency the

messages they enter manually and suggesting changes.

Several officials stated that manually-generated VMS messages had not been giving

drivers consistent legends. That is, for a given incident situation such as an accident

with a lane blocked, different TMC operators would create and display different VMS

messages in their attempts to convey the information to drivers. Also, TMC operators

typically are not trained in “human factors” regarding what types of legends and

messages are more readily understood when conveying any given piece of

information. As a result, driver response to the VMS messages had not been

optimized.

The use of symbols as the key part of VMS displays is being given emphasis in new

deployments of VMS in Europe. Symbols have been developed for “congestion,” “icy

road,” and other messages for which U.S. practice (static signs or VMS) does not yet

use symbols. A symbol for “fog” is currently being developed and researched. Because

of the many languages of Europe, symbolization is a very high priority. However, this

is increasingly important in the United States as well, with increasing immigration of

non-English speaking people and increasing tourism from many foreign countries.

The software systems (such as “SATIR” in France) incorporate human factors

knowledge into an “expert system” that reviews the facts of the incident (type,

Figure 99. Real-time travel time information, France.
55

CHAPTER 5

location, level of inconvenience, detours, etc.) and generates the appropriate VMS

message from a “pre-approved,” pre-formatted set of available messages which

conform to rules governing message format, length, and allowable phrases. The

message can be either displayed automatically or presented to the TMC operator for

verification and authorization before being displayed. Other software systems do not

generate messages but instead serve as a check for the TMC operator. The operator

types in the message he or she intends to display and the “expert system” software

checks the message for consistency with pre-approved standard messages for various

incident conditions. This “check” is automatically performed by the system and cannot

be bypassed by the operator. However, if circumstances dictate, the operator can

override the system-generated message and use his or her own wording.

Real-Time Parking Information

The team observed extensive implementation of systems that collect and display realtime information on parking availability for drivers in a variety of European cities.

These systems are typically part of larger efforts to promote and preserve the

economic viability of city centers and/or projects to enhance information to travelers

on all modes of travel into the city.

The real-time parking information systems typically utilize detectors or other means

of counting vehicles as they enter and leave parking garages or lots. This allows the

number of vacant spaces to be calculated for each parking facility on a real-time basis.

Although predominantly publicly owned parking facilities are included in the

systems, in some cities privately owned facilities have also been included, through

agreement with the owners.

Display of the real-time information to drivers is

via variable message signs (VMS) and parking

trailblazers with integral VMS panels. On major

routes leading to the city center, drivers first

encounter a VMS on the outskirts of town that

generally advises either that parking downtown is

available or is full. In the case of a “full” or nearly

full condition, some systems give messages

advising drivers to use transit and giving them

directions to the nearest park-and-ride lot.

As drivers get closer to downtown and approach

“decision points” where they can choose among

routes to various parking facilities, they encounter

parking trailblazers with VMS panels displaying

real-time numbers of available spaces in two or

more garages or lots. Figures 100 through 102

illustrate real-time parking information signs.

Figure 100 illustrates a sign on the outskirts of a city that indicates that parking is

available (frei indicates availability, not cost). Figures 101 and 102 illustrate signs

Figure 100. Real-time parking information,

Germany.
56

CHAPTER 5

that indicate the parking availability for specific parking areas. Some of these signs

may display the actual number of available spaces instead of simply indicating

general availability of parking. These trailblazers are deployed comprehensively at all

decision point intersections and at the entrances to individual parking facilities. For

example, in Cologne, Germany there are 90 such locations of real-time parking

trailblazer assemblies.

This real-time information has produced the following benefits:

• Enhanced economic viability of the downtown. People who would have

otherwise not come downtown to shop or eat because they feared parking

problems are making trips downtown.

• Enhanced use of transit due to timely messages that all downtown parking is

full and diversion of trips to park-and-ride lots serving transit lines to

downtown.

• Reduction of 25 percent in downtown traffic volumes related to “searching for a

parking space.”

Traffic Information on FM Radio

In France, the entire 4,000-mile national network of freeways is being instrumented

with FM radio transmitters, centrally programmed and operating 24 hours a day on a

single frequency, 107.7 FM. The traffic information station concept has been in place

since 1988 and has been growing. As of 1998 about 60 percent of the freeway mileage

is covered by the transmitters. The series of privately-operated but governmentregulated radio stations is known as “Autoroute FM,” and it is dedicated to providing

real-time traffic and incident information to freeway motorists. The stations

broadcast routine reports every 15 minutes for the whole network on traffic and

weather conditions, construction locations, etc. In between these reports, the stations

broadcast safety advice, tourist information, music, and advertising. Whenever an

incident, accident, congestion, or adverse weather event occurs and is detected

automatically or manually on any section of freeway, “news flashes” are broadcast

Figure 101. Real-time parking information, Germany. Figure 102. Real-time parking information, Germany.
57

CHAPTER 5

immediately (no more than 5 minutes after detection) on 107.7 FM. Signs spaced at

about 4-mile intervals contain beacons and/or VMS panels that are activated to alert

motorists not already tuned to 107.7 that a flash is about to be broadcast. Similar to

“expert systems” that assure consistency of VMS messages, the French “Autoroute

FM” system also utilizes software to maintain consistency and accuracy of the “traffic

flash” oral messages broadcast.

The French officials feel that the use of a dedicated FM frequency for incident traffic

information is much more cost effective than can be achieved with VMS signs in

sufficient quantity to equal the coverage of radio transmitters. Broadcasting also

affords more flexibility of messages and more information can be conveyed quicker

than with VMS.

RDS-TMC

The radio data system-traffic messaging channel, or RDS-TMC, is a radio-based

traveler information system that is in wide use in Europe. RDS adds a digital data

channel to existing analogue FM radio broadcasts. This silent subcarrier

automatically tunes the radio to the strongest signal for the chosen station, identifies

stations that carry traffic announcements, and then interrupts radio programs,

cassettes, or compact discs with local traffic news. RDS-TMC inserts a stream of the

latest traffic bulletins into the RDS signal. These messages are coded and can be

delivered to the driver through a number of means including synthesized voice, alphanumeric character displays, and graphic screen displays. RDS-TMC improves the ease

of obtaining information and it can provide information more timely as it does not

have to be squeezed into a broadcaster’s program schedule. The coded messages can

be translated into any language regardless of what country they are sent or received

in. Filtering can be applied so that drivers are not bothered by traffic news that is not

relevant to them. RDS-TMC has the potential to transform driving in Europe.

Navigation systems will no longer have to be static. They will provide directions

which are dynamic, updated with incident warnings. While RDS technology has been

on the market since 1987 and there are large numbers of cars that are equipped with

RDS, there are still some technical, quality, and commercial issues that must be

resolved before there is widespread operational use of RDS-TMC. Technical issues

center on the codes that make the message automatically translatable into any

language. Service quality issues revolve around the requirements that the Traffic

Information Centers need a continuous feed of up-to-date data themselves to make

the transmissions valuable. The cost of RDS-TMC has introduced the prospect of

paying for the service by means of commercial ventures. Officials anticipate that

these issues can be resolved because there is enough will and commitment in many

European countries to utilize RDS-TMC to improve the quality and timeliness of

driver information and give Europe safer and more efficient traffic and travel

services.

MATTISSE

MATTISSE will enable up-to-the-minute travel information to be exchanged, allowing

nine local authorities in England-Birmingham, Leicestershire, Warwickshire,

Coventry, Sandwell, Walsall, Solihull, Dudley, and Wolverhampton (with five urban
58

CHAPTER 5

traffic control centers, a freeway control center, a public transit center, the National

Exhibition Center, and the International Convention Center) to respond more quickly

and efficiently to travel problems. The system will also allow the public access to this

information. People will be able to plan their journeys with more confidence by

choosing the most convenient and efficient method of travel and finding the quickest

route. The system will therefore help to reduce traffic congestion, exhaust pollution in

urban areas, and the stress of travel. The system will benefit authorities by allowing

greater cooperation.

MATTISSE is partly funded by the European Commission and is expected to make a

significant contribution to the Europe-wide objective of promoting a more integrated

transportation system in urban areas. Other sites selected by the European

Commission to demonstrate the benefits of an integrated system are: Athens, Greece;

Turin, Italy; Stuttgart, Germany; Gothenburg, Sweden; and Toulouse, France.

Private Sector Collection of Traffic Data for Traveler Information

Private sector companies have developed many telematics solutions throughout

Europe. An outstanding example of this was observed in Germany, where a company

named TEGARON has developed many telematics solutions including: a traffic

information service that automatically calls you back before you get stuck in a traffic

jam; an integrated information and emergency assistance package that provides

drivers with comprehensive traffic information services plus full roadside assistance

and breakdown services; a fully automated emergency call system; and an intelligent

car navigation system that works out the shortest and quickest route to the driver’s

destination.

The key to the high standard of service provided by these companies is instant access

to accurate and up-to-the-minute data. Infrared sensors installed by a private

company along autobahns and expressways monitor current traffic densities and

provide a detailed breakdown of the traffic in terms of vehicle numbers and vehicle

types. For a small annual permit fee, state governments allow private sector

companies to install and maintain these detectors on the state’s existing bridge

infrastructure. In Germany, one private sector company plans to install these

detectors on 8,000 kilometers of the freeway network at a typical spacing of 4

kilometers. Multiple detectors will be installed at each of these 2,000 locations.

Currently, the private sector company is not required to provide the government the

real-time data from these detectors; rather, it is archived and then available for

planning purposes.
59

Chapter Six

ADMINISTRATIVE PRACTICES

The team members identified a number of specific areas of discussion and

recommendations, which are presented in detail in this report. In addition, it is also

important to elevate several items, which either did not fall within the context of the

selected areas of emphasis or that related to the philosophies that established an

organizational culture that generated and/or supported innovation.

Prior to addressing the selected administrative issues in more detail, it is important

to understand that there are distinctive differences as well as remarkable similarities

between the European Community and the U.S. Nationally, the use and acceptance of

mass transit and multimodal transportation options are much more accepted by the

citizens of Europe. They have long term acceptance and transportation practices that

reflect this philosophy. To emphasize this fact it is acknowledged in Sweden that the

motor vehicle is actually secondary to pedestrians, bicycles, and mass transit. This

was apparent in signing practices and the use of innovative traffic management

techniques. For most areas of the United States, this is an unacceptable priority and

reflects the need to market these types of ideas even in our most congested areas.

Finally, it was also interesting that the motorists in each country seemed to be more

willing to obey and conform to traffic controls and regulations. It was not the purpose

of this tour to focus on societal issues, but rather on traffic engineering design and

operational practices that are different from those used in the United States.

The similarities are more consistent with, and in some cases more advanced than

those facing transportation professionals in the United States. The environmental

considerations in each country visited are

critically important to the decision process

and dictate to a great extent the rapid

development and deployment of innovative

traffic controls and traffic management

philosophies to address safety, congestion,

and operational efficiency in lieu of major

road construction projects. The funding

clearly seemed to be more constrained and

resulted in more acute organizational

reengineering, staff reductions, and

justification strategies as transportation

initiatives often affected funding availability.

The tour members identified a comprehensive

listing of all administrative issues from each

country and established priorities of those

which either reflected consensus or achieved a level of support among the group that

suggested identification and amplification would be beneficial to the content of this

report. It is important to note that there are no recommendations specifically

The environmental considerations in

each country visited are critically

important to the decision process and

dictate to a great extent the rapid

development and deployment of

innovative traffic controls and traffic

management philosophies.
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CHAPTER 6

identified in the Administrative Issues segment of this report (no Primary Findings)

and although each selected area represents important findings, the focus of this

report and the recommendations presented relate to more transferable traffic control

innovations. The group did, however, identify a number of important initiatives or

philosophies which were very basic to the understanding and integration of all the

innovations in traffic control which are addressed in this report.

PRIVATE SECTOR

In each country visited the relationship between the private sector and government

was quite advanced. In fact, the line of demarcation between government functions

and the private sector was often difficult to identify. In Sweden the city government

performed many of the functions that private enterprise embraces in the United

States. As an example, Gothenburg made

their own signals and even competed in the

market place in other countries with their

products. In each visited country the

collection of traffic data was generated by

both public and private sector and even

though there were differences in how these

data were collected, the basic purpose was

to provide the motorist with real-time and

effective traffic and congestion information.

Perhaps the most impressive

demonstration of this type of partnership

was with COFIROUTE, a private freeway

company in France. This company

essentially completed a design-buildoperate facility, which was as impressive

and efficient as any such facility any team member had knowledge of. The

organizational culture of this private sector group was such that any future expansion

or additional toll facilities in an environment of reduced road construction would be

the result of customer service and marketing skills.

Perhaps the most impressive aspect of this operation was the marketing of the facility

both prior to construction and after its opening. It was apparent that COFIROUTE

considered marketing and corporate citizenship as guiding principles in all aspects of

this operation. They had developed extraordinary processes of “selling” the product at

all levels of government and citizen groups. As this type of business practice continues

to expand in the United States, this operation should be carefully studied and lessons

learned adopted as appropriate.

As a result of reengineering initiatives and reductions in the strength of available

human resources, each country visited had moved the contracting of some of the

traditional public sector activities to the private sector. This element of

administrative process was found to be consistent with the efforts underway in the

United States, and innovation and reassessment were the standards rather than

exceptions. Each country retained the responsibility for policy and standard

development to manage the national roadway infrastructure.

As a result of reengineering initiatives

and reductions in the strength of

available human resources, each

country visited had moved the

contracting of some of the traditional

public sector activities to the

private sector.
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CHAPTER 6

TECHNOLOGY DEVELOPMENT

One philosophical difference found that was of particular interest to the group was

discussed at length in Germany and also found to be prevalent in other countries. In

the United States, as the technology activities became more recognized as an integral

part of transportation initiatives, the individual States and Federal Government

made every effort through research, early deployment projects, and organizational

structure realignments to better accommodate this significant change in the way they

did business. This has normally resulted in the segregation of these types of activities

into technology groups within existing organizational structures. This has worked

very well in elevating ITS into the application of technology solutions for

transportation problems. This process was also prevalent in the European

Community, but recent developments in this area are very interesting and should be

formally considered in this country. Germany has begun the process of reintegrating

telematics (ITS) into the more traditional operational, maintenance, and construction

areas, while retaining the emphasis on safety and traffic management.

This reflects the evolution of transportation technology and indeed makes good

business sense as communications are enhanced and ITS becomes a normal part of

transportation and transit management practices. This is a very critical management

philosophy if the integration of technology is to continue to advance and become

accepted as another important tool by planners, designers, traffic engineers, and

maintenance staff. This concept would also increase the marketability and customer

acceptance of ITS.

SAFETY

In Sweden the national government and the

Swedish National Road Administration

(SNRA) have adopted a fundamental guiding

principal identified as Vision Zero. This

principal essentially equates to some of the

national goals in the United States relating to

accident and severity, but was clearly

integrated throughout the SNRA

organization. The purpose of this concept was

to establish a national road traffic safety

target, which would provide a fundamental

element in all business decisions to achieve

this goal. This philosophy has become a

marketing tool for communicating with the

customers as well as being adopted

throughout the organizational culture as the basic goal of the organization. In

England a similar organizational strategy was used, which was identified as “Value

for Money.” This concept again is not unusual in this country but represents the

focusing of attention on an organizational value that is prevalent and considered in

all business decisions. This focus area was critical in England as road and

transportation funds competed with other important national program areas, and

The safety focus area was critical in

England as road and transportation

funds competed with other important

national program areas, and very clear

financial assessments were both

necessary and consistent with national

policy directives.
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CHAPTER 6

very clear financial assessments were both necessary and consistent with national

policy directives.

OTHER OBSERVATIONS

In addition to the administrative issues described previously in this chapter, the team

members observed or learned of other administrative activities that may be of

interest to U.S. practitioners.

Integration of Transportation Modes

The tour group found additional administrative issues both interesting and consistent

with the group’s interest in innovative traffic controls. These issues also related to the

long and successful history of the European Community in the integration of modal

transportation and inter-jurisdictional cooperation. The involvement of the customer

in solicited input, information distribution to the user, and consistency in meeting

schedules have all added to the effectiveness of jurisdictional cooperation and

customer satisfaction. For example, we observed this in their integrated terminals for

buses, trains, and subways and their accommodation of vehicles, buses, bikes, and

trollies in the traffic signal control.

Policy

The Europeans also stress translating policy into legislation, a mind-set also

consistent with the needs in traffic control strategies in the United States. In

Germany the national legislation related to variable speed limits was the

fundamental element in the implementation process as well as the success of the

program.

Coordination

Perhaps some of the most meaningful discussions for the group were held in Germany

with the Federal Highway Research Institute (BASt). BASt is a research and

technical institute that began in the highway construction field and expanded

through the years to become the focus for highway transportation research in that

country. The quality and comprehensive nature of many of their projects were very

consistent with much of the ongoing research in the United States, and the tour group

felt it would be very beneficial for the Federal Highway Administration (FHWA) and

Transportation Research Board (TRB) to pursue a closer relationship with this

excellent program to help maximize the research funds available and not duplicate

compatible projects.

In-Vehicle Messages

From an administrative perspective the group found it interesting that one common,

serious concern between the tour group and our hosts was that the in-vehicle and

road side messages had the potential to be incompatible. The work going on in these

areas is being conducted without regard to the need for future consistency.
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Chapter Seven

RECOMMENDATIONS

The ten members of the Innovative Traffic Control team were privileged to travel to

four European countries (Sweden, Germany, France, and England) and see firsthand

many outstanding traffic control practices. The team unanimously believes that

traffic engineers and transportation professionals from the United States can

significantly benefit from the team’s experiences on the trip. The most significant of

those experiences are described in the preceding chapters of this report.

Following the meetings with the host countries, the team members met to review the

findings from the trip and identify those practices which have the greatest potential

for successful implementation in the United States. This chapter describes the

recommendations that have evolved from the team’s experiences on the trip. The

recommendations in this chapter are organized by major topics (consistent with the

chapters of this report). Within each major topic, the recommendations are divided

into Primary Recommendations and Additional Recommendations (consistent with

the Primary Findings and Other Observations within each chapter). This chapter also

includes a section on Implementation Efforts, which describes team members’

activities to implement their findings and recommendations.

TRAFFIC CONTROL DEVICES

The team members learned about and observed many interesting applications of

traffic control devices. In some cases, the applications were described by the hosts

during meetings with representatives from

the various countries. In other cases, team

members directly observed applications as

they traveled within each country.

Primary Recommendations

The team developed two primary

recommendations that relate to applications

of traffic control devices. Both relate to

pavement markings. The first represents an

application that could be implemented

without significant changes in standards or

guidelines. The second would represent a

major change from how pavement markings

are used in the U.S.

Tiger Tail Marking

In England, team members observed special

markings that were used on multilane

freeway entrance and exit ramps. These markings separate the merge/diverge point

associated with each lane, thereby improving the operational characteristics at the

entrance/exit ramp. This type of marking could be immediately implemented in the

One team recommendation

concerning pavement markings

involves an application that could be

implemented without significant

changes in U.S. standards or

guidelines; the other would represent

a major change from how pavement

markings are currently used in the

United States.
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CHAPTER 7

United States. The major implementation obstacle is that multilane ramps that use

this marking require greater pavement area than normally found on U.S. freeways.

Therefore, implementation of this concept would require revision of geometric design

standards for multilane entrance ramps. This type of marking may be especially

useful at locations where the freeway entrance ramp is fed by two turning lanes from

the cross road.

All-White Pavement Markings

The concept of an all-white system of pavement markings has been the subject of

much discussion in the United States in recent years. Several of the team members

are very familiar with the issues and arguments associated with U.S. discussion of

the issue. As they traveled through Europe, the team members were very impressed

with the European all-white system and felt that such a system could work in the

United States, although there would be a significant effort associated with

implementation. Standards would have to be changed, new marking put in place, and

drivers would have to be educated. Appendix D contains a problem statement

developed by the team that describes the research needed to initiate a change to an

all-white system of markings.

Two key characteristics of the European all-white system must be considered when

evaluating whether such a system has potential application in the United States. The

first is that European countries use a wide variety of pavement marking patterns

(line width, line/gap ratios, number of lines, symbols, etc.) to convey various messages.

Implementation in the United States would require that new marking patterns be

used to distinguish the messages currently conveyed by yellow and white markings.

The second key characteristics is that team members observed that, on many of the

roadways they traveled, there were significantly greater amounts of markings than

used on U.S. roadways, and the markings appeared to be better maintained systemwide than in the United States (on all classes of roads and at all levels of government

jurisdiction). Europeans place a significant emphasis on using markings to

communicate information (see horizontal signing section). Implementation of allwhite in the United States would likely require that agencies devote greater

resources to markings than they currently do. The potential benefits, however, are

significant, and include:

• White markings have greater visibility than yellow markings.

• White markings offer better contrast than yellow markings.

• White markings offer economic incentives, including:

– White material is less expensive.

– Use of only one color improves application efficiency, reduces storage

demands, and reduces hardware requirements.

• Use of an all-white system would increase U.S. consistency with international

practices.

The most significant of the disadvantages of an all-white system would be the

extensive educational efforts that would be required prior to and during its

implementation of an all-white system. Another disadvantage includes coordinating
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CHAPTER 7

the change with other countries that use a yellow/white system (Canada and

Australia),

Finally, it should be noted that the use of yellow in pavement markings has changed

continually in the United States since the early days of traffic control devices. Prior to

1961, white was the primary color used in the United States, with yellow being used

only to mark no passing zones. It was not until 1978 that current practices for yellow

pavement markings (yellow indicates the left side of the roadway) were established.

Research in the United States has shown that large percentages of drivers do not

understand the difference between yellow and white markings. For these reasons,

change to an all-white system may actually be welcomed by some drivers.

Additional Recommendations

In addition to the Primary Recommendations described above, the team members

identified several applications of traffic control devices that may have value to U.S.

practitioners. Some of these can be implemented relatively easily and others will

require some research and changes to current standards. The key aspects associated

with these additional recommendations are described below.

• Countdown Markers for Exit Ramps – Special markers are used in

advance of exit ramps in all four countries. These markers indicate when a

driver is 300, 200, and 100 meters from the exit.

• Sign Colors More Intensive – As the team members viewed signs in each of

the countries, they developed an opinion that the European sign colors are

more intensive than those used in the United States. Researchers should

determine if these colors are more effective than the U.S. sign colors.

• Arrowhead Shaped Destination Signs – In many of the directional signs in

Europe, the direction is indicated by an arrow in the sign legend and by the

fact that the sign has an arrowhead shape that reinforces the direction

indicated by the legend. This concept is already used with One-Way signs in

California and could be easily incorporated into destination and directional

signs.

• Internal Sign Illumination in Urban Areas – The team members observed

a large number of internally illuminated signs in the urban areas. In areas

with complex visual fields, these signs appear to have much better target value

than retroreflective signs.

• Use of Dotted Border for Trailblazing – In a guide sign, a dotted border

around a route marker indicates that the exit or road leads to that route. This

is a more simplified means of trailblazing than is used in the United States

(TO marker).

• Guide Sign Sheeting Types – In Germany, officials are utilizing

combinations of different sheeting types in ground-mounted signs and super

high intensity sheeting in overhead signs.

• Variations in Alphabet Stroke Width – The sign alphabets used in

European signs are different from the standard U.S. alphabets. A significant

difference in application can be found in the relationship between stroke width
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CHAPTER 7

and sign background. The English alphabet uses a bolder stroke width on

signs with a light colored background. Because of the significant differences in

performance between positive and negative contrast signs, the use of different

stroke widths is inherently logical.

• Horizontal Signing – The Europeans utilize pavement markings to

communicate information to a much greater extent than used in the United

States. This use is so prevalent that it is referred to as horizontal signing. The

team members believe that many of these horizontal signing applications

could have significant benefit in the United States.

• Chevrons for Vehicle Spacing – Information provided by England’s

Highways Agency indicated that some English highways feature regularly

spaced chevron markings in lanes. Associated signing informs drivers to keep

two chevrons between them and the vehicle they are following.

• Colored Pavements – Team members saw applications of colored pavement

that indicate lanes for a specific type/class of vehicle. The applications

observed related to bus lanes and bike lanes.

• Raised Crosswalks – In many locations, team members observed raised

pedestrian crosswalks. This treatment serves to increase the visibility of the

crossing and also functions as a speed hump to slow approaching vehicles.

• Flashing Yellow on Pedestrian Clearance – After the red indication at the

start of the pedestrian clearance interval, some crosswalks in England display

a flashing yellow signal indication to vehicles. The flashing yellow allows

vehicles to proceed if pedestrians have cleared the travel lane.

• Audible Pedestrian Signals – Many of the European cities, particularly

Gothenberg, utilized audible pedestrian signals.

• Worker Visibility Enhancements – Work zone and maintenance workers in

Europe utilize more visible garments than their U.S. counterparts. European

work vests tend to emphasize strong yellow-green and often use two

contrasting colors to prevent workers from blending in with the background.

• Vehicle Visibility Enhancements – Both agency and police vehicles in

Europe utilize vehicle visibility enhancements such as large amounts of

retroreflective sheeting and fluorescent colors. This makes these vehicles

significantly more visible than the U.S. counterparts.

• Work Zone Traffic Control – Team members observed various applications

of work zone traffic control that may enhance the effectiveness of the devices.

These include greater retroreflective material on traffic cones and the use of

strobes on devices that indicate a change in the travel path.

• Freeway Exit Signs – European agencies employ a broad range of practices

in the use of freeway guide signs. Several photos present typical European

freeway guide signs.

• Rotary Intersections – Rotary intersections are receiving increased

attention in the U.S. Several photos present typical European practices for the

use of traffic control devices at rotary intersections.
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FREEWAY CONTROL

In the major urban areas, the freeways (or

motorways as they are known in Europe)

utilize many traffic control practices that

improve operations and/or safety of the

system. The team members identified three

of those practices as primary

recommendations and two others as

additional recommendations.

Primary Recommendations

In all four countries, team members found advanced systems for monitoring and

controlling the traffic on the most heavily traveled freeways. Three of the traffic

control practices have potential value in the United States. Implementation of these

practices should be considered as a system, rather than individual practices. The

benefits realized from implementation of the system will be greater than the sum of

the individual practices.

Variable Speed Control

A major difference between U.S. and European freeways is their ability to adjust the

regulatory speed limit to reflect traffic conditions. This is done quite successfully

using variable message signs that display the European speed limit graphic (a

number inside of a red circle). A supporting element of the variable speed control is

automated camera enforcement. This was used in all the countries. In at least one

country, automated enforcement was cited as a major reason why drivers obeyed

variable speed limits.

The team believes that U.S. freeway operations could be significantly improved

through the use of variable speed limits. However, there are many issues that need to

be addressed before such a practice can be implemented. Among these issues are the

design of the speed message, the legalities associated with variable speed limits,

procedures for selecting and displaying speeds, and enforcement of variable speed

limits. Appendix D contains a problem statement developed by the team that

describes the research needed to move toward the use of variable speed limits. This

problem statement also addresses lane control signals (see the next recommendation).

Lane Control Signals

Lane control signals are already in use on many U.S. freeways as a traffic control

practice. However, there are at least two differences between the U.S. and European

practices. In Europe, the lane control signals function in coordination with the

variable speed limits to slow vehicles down and move them to the desired lane in

advance of an incident or capacity reduction. The other difference is the European use

of the diagonal down yellow arrow. This symbol is not currently allowed by the U.S.

MUTCD, and should be reevaluated for application in the United States.

Lane control signals can be easily implemented on U.S. freeways with a minimal

amount of change to U.S. standards. Those standards should be modified to provide

In all four countries, team members

found advanced systems for

monitoring and controlling the traffic

on the most heavily traveled freeways.
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CHAPTER 7

the use of a downward pointing diagonal yellow arrow. Research recommending this

use of this display has already been conducted in the United States. (11, 12) In addition

to the variable speed limit issue, the problem statement in appendix D also addresses

the coordinated use of lane control signals with variable speed limits.

Incident and Queue Detection and Protection

Although not technically a traffic control device or practice, the ability of European

agencies to detect incidents and queues are an important element of their freeway

control systems. The most heavily traveled freeways have extensive detection

capabilities and well-developed algorithms for detecting incidents and queues. Once

identified, various measures are used to implement control strategies. The primary

measures are the variable speed control, the lane control signals mentioned

previously, and back-of-queue detection. The use of these control measures are often

automated into the overall system so that the delays associated with human

intervention are eliminated.

U.S. transportation agencies should design new freeway information and control

systems to more systematically protect against the safety problems associated with

queues. Incident management schemes should provide greater warning of queues

through the use of warning vehicles and devices.

Additional Recommendations

In addition to the Primary Recommendations described above, the team members

identified two other aspects of freeway control that may have value to U.S.

practitioners. The key aspects associated with these additional recommendations are

described below.

• Rolling Freeway Block – In England, the police sometime use a rolling

freeway block to clear debris or other obstacle from the freeway. Police vehicles

occupy all the lanes across the freeway and slow to a speed that allows the

desired operation (lane closure, debris removal, etc.) to be conducted.

• Shoulder Detection – Incidents on freeway shoulders can have a noticeable

impact on the overall operations of the facility. European officials have

addressed this issue by placing detectors on freeway shoulders. This option

should be considered for new construction in the U.S. on facilities that have

traffic management systems.

OPERATIONAL PRACTICES

During the meetings with representatives from each country, the team members

learned much about how the four countries operate their respective transportation

systems from a traffic control perspective. The team members believe that two of

these operational practices have potential value in the United States. There are also

other operational practices that may be of value to U.S. practitioners.

Primary Recommendations

The team members learned of two operational practices that function in a traffic

control manner. The first provides the ability to influence the speed of vehicles in
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CHAPTER 7

target areas. The second is an improved operational strategy for increasing the safety

of traffic signals operation at isolated intersections.

Intelligent Speed Adaption

In Sweden, the team members learned that Swedish authorities have developed

systems that can directly or indirectly influence the speed of vehicles in target areas.

Within these target areas, vehicle speeds can be monitored. When a vehicle’s speed

exceeds a threshold, two options are possible in vehicles equipped to receive the

signal. The system can set off an alarm within the vehicle, alerting the driver to a

speeding violation. Or the system can physically reduce or limit the speed of a vehicle

so that the driver is not capable of driving faster than the speed limit.

To make it possible to introduce these systems in the United States, large-scale tests

must demonstrate that the voluntary systems have a positive effect on the road traffic

system, the users accept the systems, people are prepared to pay for the systems, and

the relevant authorities will support the necessary infrastructure.

Self Optimizing Signal Intersection Control

Also in Sweden, the team members learned of strategies that Swedish engineers have

developed for operating traffic signals at rural, high-speed, isolated intersections. In

essence, the Self Optimizing Signal (SOS)

intersection control provides an improved

strategy for ending the green phase. The

strategy emphasizes safety and economical

factors in determining the optimal time to

terminate the green.

The SOS control system, or at least the

conceptual logic by which it controls traffic

signal intersections, appears to offer much

promise for application in the United States

at high speed, isolated, traffic signal

installations. While shortcomings with the current system, as developed to date, have

been identified by Swedish officials, they are confident solutions to those deficiencies

are attainable. In the meantime, there are temporary fixes for some of these

shortcomings. For example, the temporary solution for the congested traffic condition

problem is to disable the optimization function of the system when congested

conditions exist. The many advantages provided by SOS control could be used at all

other times.

Detection systems required for optimal SOS control could cost $10,000 to $20,000

more than the typical intersection detection systems in use in most areas of the

United States. Given the potential safety benefits (significantly reducing the potential

for rear end crashes and red light running) however, the extra costs for the detection

required would be more than compensated for through a small reduction in crashes.

Swedish experience indicates that the crash reductions needed for pay-off of the

additional costs are likely.

In essence, the Self Optimizing Signal

(SOS) intersection control provides an

improved strategy for ending the

green phase.
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Appendix D contains a problem statement developed by the team that describes the

research needed to introduce SOS signal strategies into U.S. practice.

Additional Recommendations

In addition to the Primary Recommendations described above, the team members

identified several operational practices that may have value to U.S. practitioners.

These practices should be able to be incorporated into U.S. practices with little or no

changes in current standards or without extensive research. The key aspects

associated with these additional recommendations are described below.

• Use of Historical Loop Data During Loop Failure Conditions – In

Sweden, signal controllers and detectors incorporate logic that allows them to

use historical data for signal operation when a loop fails. This provides more

effective signal operation than is realized from the continuous detector call

associated with loop failure in the United States.

• Coordinated Signal Preemption Strategies – In Sweden, the use of signal

preemption for transit vehicles became so common that the benefits of

coordinated signal operation were lost. The SPOT system provides a means of

coordinating preemption and progression.

• Automated Speed Enforcement – Automated photo speed enforcement is

widely employed by European agencies. Enforcement cameras were observed

on a wide range of roadways. Officials in England indicated that automated

enforcement was a key factor in the effectiveness of the variable speed limits

used on freeways. U.S. application of this practice is likely to be very

controversial.

• Emergency Phones – The team members observed widespread use of

emergency phones on European freeways. Even with the rise in cellular

telephone use, these roadside phones continue to provide an important means

of assisting motorists.

• Elevated Police Patrol Bays – In England, team members observed that

police patrol vehicle bays alongside the freeway were elevated to provide

enforcement personnel with a better view of traffic.

INFORMATION MANAGEMENT

As they met with practitioners in each country and as they traveled on each country’s

transportation network, the team members realized that the Europeans have devoted

significant resources to communicating information to the system users. And the

Europeans do an admirable job of managing that information.

Primary Recommendations

The team members recommend two practices related to information management for

implementation in the U.S. One practice is wider use of symbols in variable message

signs and identification of diversion routes. The other is the communication of travel

time information to road users.
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Symbolics

As expected, the Europeans make much greater use of symbols in their transportation

system. However, the team was impressed by the extent to which symbols are used in

variable message signs. Much of this information could be easily incorporated into

variable message signs in the U.S. using the standard U.S. symbols. The Europeans

also use symbols to identify freeway diversion routes. When it is necessary to divert

traffic from the freeway, signs indicate the appropriate diversion symbol. This symbol

is displayed at all decision points along the route. Road users need only to follow the

symbol as they travel on the alternate route.

Display of Travel Time Information

The team members also observed outstanding

examples of travel time information being

communicated to road users. The best

example of this practice was in Paris, where

variable messages signs on the inner and

outer ring roads, plus the entrance and exit

ramps, inform road users of the real-time

travel time to key points in the network. This

information is updated on a minute-byminute basis. This information is extremely

useful to drivers and similar applications

would be equally useful to U.S. drivers where

congested conditions occur.

Additional Recommendations

In addition to the Primary Recommendations described above, the team members

identified several applications of information management that may have value to

U.S. practitioners. Some of these can be implemented relatively easily and others will

require some research and changes to current standards. The key aspects associated

with these additional recommendations are described below.

• Consistency in Variable Message Signs – The Europeans achieve

consistency in VMS sign information by operating VMS as a centrally

controlled system. Consistency and standardization of VMS messages is

viewed in Europe as an important safety issue and their work in this area

should be a model for the United States in developing standards, operational

practices, and software systems.

• Real-Time Parking Information – In Germany and England, team

members observed variable message signs that communicate information

about the availability of parking in various areas of the city. Such systems are

also used in other parts of Europe. This information allows drivers to make

informed routing decisions as they travel to available parking nearest their

destination. This type of information system should be considered for U.S.

deployment.

The best example of travel time

information was in Paris, where

variable message signs on the inner

and outer ring roads, plus the

entrance and exit ramps, inform road

users of the real-time travel time to

key points in the network.
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• Traffic Information on FM Radio – The French are using a dedicated FM

radio frequency throughout the country to provide travelers with traffic

information. U.S. practitioners should consider the use of an FM frequency

instead of the AM frequencies currently used in highway advisory radios.

• Radio Data System Traffic Messaging Channel – The Europeans have

developed this technology to provide traffic information throughout the

continent. It is a radio-based traveler information system that automatically

tunes the radio to the appropriate frequency, regardless of current radio

operation (commercial station, cassette, or compact disc), to broadcast the

information. The system provides coded information that can be easily

translated to the appropriate language for the vehicle’s occupants, regardless

of the source of the data.

• MATTISSE – MATTISSE is a travel information system being developed in

England. Its primary purpose is the exchange of information among multiple

agencies and jurisdictions so that travel problems can be addressed more

efficiently. The information will also be available to the public.

• Private Sector Collection of Traffic Data for Traveler Information –

Throughout Europe, team members observed many outstanding examples of

private sector companies collecting traffic data and providing it to subscribers.

An outstanding example of this practice was observed in Germany. TEGARON

is a private-sector company that provides travel information to subscribers.

Team members were impressed by the high standard of service provided by

this company and the cooperative agreements between the company and

transportation agencies.

ADMINISTRATIVE PRACTICES

These highlights of administrative issues are not a comprehensive listing of the many

and varied inputs provided by transportation, transit, and research hosts the tour

group had the good fortune to encounter. Our group collectively and individually will

always be indebted to the many professionals in Sweden, Germany, France and

England for their hospitality and willingness in sharing both successes and failures.

In the recommendations presented in this report and any future pilots or

implementation strategies, team members cannot overemphasize the need to fully

consider the administrative side, as well as the engineering and scientific aspects. It

will be particularly important to do a much better job of marketing and determining

what the customers really desire. The engineering community has never been as

efficient in this area as will be necessary to implement innovative traffic control

technologies. As previously noted there are also significant differences in the

European community, as there are remarkable similarities. Care should be taken in

each recommendation and assessment of all administrative issues, as there will not

be a true relationship between functionality and application in all cases.

IMPLEMENTATION EFFORTS

Team members began implementation efforts almost immediately upon their return

to the United States in mid-May 1998. Within a month of returning, the team

members had produced a six-page summary of the preliminary findings and
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recommendations. This summary, along with the many photos and videos that team

members took during the trip, served as the basis for several early presentations on

the trip. Table 5 lists the presentations that team members have made or planned

regarding the trip.

Finally, a key element in implementing some of the team’s recommendations will

require some research to adapt practices and technologies to function within the

United States. This process begins with the development of problem statements that

can be submitted to research organizations. Appendix D contains problem statements

that have been developed by team members.

Table 5. Implementation presentations.

June 1998

June 1998

July 1998 to

September 1998

AASHTO Subcommittee on Traffic

Engineering

Research Committee – National

Committee on Uniform Traffic Control

Devices

FHWA Office of Highway Safety

FHWA Office of Research Development

FHWA Office of Traffic Management and

ITS Applications

Lynwood Butner, Sterling

Davis, Gene Hawkins,

Peter Rusch

Linda Brown, Gene

Hawkins, Peter Rusch,

Scott Wainwright

Linda Brown, Mark

Kehrli, Sam Tignor, Scott

Wainwright

Linda Brown, Lynwood

Butner, Sam Tignor, Scott

Wainwright

Mark Kehrli

Gene Hawkins and Sam

Tignor

Linda Brown, Gene

Hawkins

Gene Hawkins, Sam

Tignor, Scott Wainwright

Institute of Transportation Engineers Joint

Section Meeting – Washington, D.C. and

Virginia Sections

FHWA International Coordination

Committee

Transportation Research Board Annual

Meeting

American Traffic Safety Services

Association

Institute of Transportation Engineers

September 1998

October 1998

January 1999

February 1999

August 1999

Washington, D.C.

Washington, D.C.

San Antonio, TX

Las Vegas, NV

DATE LOCATION GROUP/MEETING TEAM PARTICIPANTS

San Antonio, TX

San Antonio, TX

Washington, D.C.

Falls Church, VA
74

CHAPTER 7
75

Chapter Eight

REFERENCES

1. Towards a Balanced Transport System: The Highway Agency’s Toolkit. CDROM, Version 1, April 1998, available at http://www.highways.gov.uk/.

2. Standard Specification for Retroreflective Sheeting for Traffic Control. D4956-

95, American Society of Testing and Materials, West Conshohocken,

Pennsylvania, November 1995.

3. Road Equipment – Fixed, Vertical Road Traffic Signs – Part 1: Signs. European

Standard prEN 12899-1, DRAFT, European Committee for Standardization,

Brussels, Belgium, 1997.

4. The Traffic Signs Regulations and General Directions 1994. Statutory

Instruments 1994 No. 1519 Road Traffic, Her Majesty’s Stationary Office,

London, 1994.

5. Commitment to Safety Yielded Fast Results. In VägSkäl: (CrossRoads). Traffic

and Public Transport Authority in Gothenburg, Gothenburg, Sweden, #2-96,

1996, pg. 11.

6. Traffic Control in Hessen. Hessian Road and Traffic Authority, Wiesbaden,

Germany, undated.

7. Harbord, Brian. M25 Controlled Motorway – Results of the First Two Years,

Highways Agency, London, England, February 1998.

8. Cofiroute’s DIVA System: constant surveillance for greater comfort and safety.

Cofiroute, Sevres Cedex, France, undated.

9. Kronberg, Peter, Fredrik Davisson, and Jan Edholm. SOS–Self Optimising

Signal Control: Development and Field Trials of the SOS Algorithm for Self

Optimising Signal Control at Isolated Intersections. TFK Report 1997:2E, The

Swedish National Road Administration, Stockholm, Sweden, May 1997.

10. Kronborg, Peter. MOVA and LHORVA: Traffic Signal Control for Isolated

Intersections. TFK Report 1992:4E, The Swedish National Road

Administration, Stockholm, Sweden, December 1992.

11. Ullman, G.L., S.D. Wohlschlaeger, C.L. Dudek, P.B. Wiles. Driver

Interpretations of Existing and Potential Lane Control Signal Symbols for

Freeway Traffic Management. Research Report 1298-1, Texas Transportation

Institute, College Station, Texas, 1993.

12. Ullman, G.L., K.D. Parma, M.D. Peoples, N.D. Trout. Yellow Transition Lane

Control Signal Symbols for Freeway Traffic Management. Research Report

1498-2, Texas Transportation Institute, College Station, Texas, 1996.
76

CHAPTER 8
77

Appendix A

TEAM MEMBERS

TEAM MEMBERS AND AFFILIATIONS*

Sterling C. Davis

Engineer of Traffic and Safety

Utah Department of Transportation

4501 South, 2700 West

Salt Lake City, UT 84114-3200

Phone: (801) 965-4273

Fax: (801) 965-3845

e-mail: sdavis@dot.state.ut.us

Edward L. Fischer

State Traffic Engineer

Oregon Department of Transportation

5th Floor Transportation Building

355 Capital Street NE

Salem, OR 97310-1354

Phone: (503) 986-3606

Fax: (503) 986-4063

e-mail: ed.l.fischer@odot.state.or.us

H. Gene Hawkins, Jr. (Report Facilitator)

Associate Research Engineer

Texas Transportation Institute

The Texas A&M University System

College Station, TX 77843-3135

Phone: (409) 845-9946

Fax: (409) 845-6006

e-mail: gene-h@tamu.edu

Mark R. Kehrli

Team Leader B West ITS Program

Delivery Team

Office of Traffic Management and ITS

Applications

Federal Highway Administration

400 Seventh St., SW

Washington, DC 20590

Phone: (202) 366-5465

Fax: (202) 366-8712

e-mail: mark.kehrli@fhwa.dot.gov

Dr. Samuel C. Tignor (Team Leader)

Chief, Traffic and Driver Information

Systems Division

Office of Safety & Traffic Operations

Federal Highway Administration/HSR-30

6300 Georgetown Pike

McLean, VA 22101-2296

Phone: (202) 493-3363

Fax: (703) 285-2113

e-mail: sam.tignor@fhwa.dot.gov

Linda L. Brown

Transportation Specialist

Office of Highway Safety

Federal Highway Administration/HHS-21

400 Seventh St., SW

Washington, DC 20590

Phone: (202) 366-2192

Fax: (202) 366-2249

e-mail: linda.l.brown@fhwa.dot.gov

J. Lynwood Butner

State Traffic Engineer

Virginia Department of Transportation

1401 East Broad St.

Richmond, VA 23219

Phone: (804) 367-8838

Fax: (804) 367-6631

e-mail: dmvj5b@dmv.state.va.us

Richard Cunard

Engineer of Traffic and Operations

Transportation Research Board

2101 Constitution Ave., NW

Washington, D.C. 20418

Phone: (202) 334-2963

Fax. (202) 334-2003

e-mail: rcunard@nas.edu

*At time of scan tour.
78

APPENDIX A

Peter F. Rusch

State Traffic Engineer

Wisconsin Department of Transportation

4802 Sheboygan Ave.

Madison, WI 53707-7986

Phone: (608) 266-0459

Fax: (608) 261-6295

e-mail: peter.rusch@dot.state.wi.us

W. Scott Wainwright

Chief, Division of Traffic and Parking

Services

Montgomery County Department of

Public Works and Transportation

101 Monroe Street, 11th Floor

Rockville, MD 20850

Phone: (301) 217-2190

Fax: (301) 217-2637

e-mail: wsw2@erols.com

TEAM MEMBER BIOGRAPHIES

Samuel C. Tignor, the Team Leader, is Chief of the Traffic and driver Information

Systems Division, Office of Safety and Traffic Operations, Research and Development

for the U.S. Federal Highway Administration (FHWA) in McLean, Virginia. As

Division Chief, he is responsible for planning, budgeting, promoting, coordinating, and

executing transportation research. He currently manages research pertaining to

traffic signs, marking, signals, lighting, work zone safety, railroad-highway grade

crossings, and speed control. He has served in the Office of Traffic Safety Research

Division in the FHWA for over 36 years. He completed his undergraduate degree,

B.S.C.E., at the Virginia Polytechnic Institute in 1958. He earned his M.S.E. and

Ph.D. at the University of Michigan in Civil Engineering with a transportation major.

He is Professional Lecturer in Engineering at George Washington University and a

Registered Professional Engineer in the District of Columbia. He is a member of the

American Society of Civil Engineers, Institute of Transportation Engineers, Society of

Automotive Engineers, Operations Research Society, is past chair of the TRB

Committee on Travelers’ Services, and a member of the TRB Group 3 Council.

Linda Brown is a Transportation Specialist for the Office of Highway Safety, FHWA.

She is a member of the Traffic Control Device Team and the Outreach Team within

the Office of Highway Safety. Her responsibilities include developing and interpreting

traffic control device policies and standards, collaborating with colleagues in the

research and implementation of improved traffic control device technology, providing

technical assistance transportation organizations both nationally and internationally,

and establishing marketing and outreach strategies for improving highway safety and

traffic control operations. She has done considerable work on establishing the

direction and contents for the upcoming new Manual on Uniform Traffic Control

Devices which contains the principles for design, application, and placement of traffic

control devices which aid the driver tasks of navigation, collision avoidance, and route

guidance. Ms. Brown received her B.S. degree in Transportation and Business

Management from the University of Maryland. She is a member of the Institute of

Transportation Engineers, and Women’s Transportation Seminar. She also serves as a

committee member of the Transportation Research Board, and as the FHWA liaison

to the National Committee on Uniform Traffic Control Devices.

Lynwood Butner is the State Traffic Engineer and Division Administrator of the

Traffic Engineering Division at the Virginia Department of Transportation in

Richmond, Virginia. He is responsible for the safe and efficient movement of people
79

APPENDIX A

and vehicles over the highways of the State Virginia. He is also responsible for the

development of the State’s traffic monitoring system, rail and highway safety

programs, the oversized truck assessment program, traffic calming development,

roadway system inventory, specifications and design of traffic control devices,

maintenance and publication of accident data, and the agency’s Intelligent

Transportation System initiative. Mr. Butner has over 25 years service with the

Virginia DOT and has served as a junior and senior engineer, program supervisor, and

Assistant Division Administrator. He holds an undergraduate degree from the

University of Richmond and a Masters in Public Administration from Virginia

Commonwealth University. Mr. Butner is a member of the Institute of Transportation

Engineers (ITE) and past president of the Virginia Section of ITE. He has held

numerous leadership positions in civic organizations and is a recipient of the

Commissioner’s Award for Excellence. Effective March 1, 1999 Mr. Butner has moved

to the Virginia Department of Motor Vehicles as Assistant Commissioner, Motor

Carrier Services.

Rich Cunard is the Engineer of Traffic and Operations for the Transportation

Research Board (TRB) in Washington, DC. In this capacity, he is responsible for the

technical activities undertaken at TRB related to traffic engineering and control,

traffic operations, intelligent transportation systems, and automated highway

systems. He has authored numerous technical papers and articles on traffic control,

operations, and safety issues. Mr. Cunard has served with TRB for more than 9 years

and has over 20 years of experience in traffic engineering and safety for public and

private agencies. He is a graduate of Wayne State University with B.S. and M.S.

degrees in Civil Engineering and is a licensed Professional Engineer. Mr. Cunard is

active in several national and international professional associations and societies

and serves on international technical program committees in the areas of intelligent

transportation systems, traffic control, traffic engineering, and traffic safety.

Sterling Davis is the Engineer for Traffic and Safety for the Utah Department of

Transportation in Salt Lake City, Utah. He is responsible for developing Statewide

policies and procedures for the establishment and use of standardized traffic control

devices on all State highways. He has almost 30 years of experience as an engineer

with the Utah DOT, and served as a District Director in two rural districts for a total

of over 16 years, performing the traffic engineering duties for those districts. He has a

B.S. degree in Civil Engineering and a Master of Engineering Administration, both

from the University of Utah. Prior to working with the Utah DOT he spent 6 years as

a Civil Engineering Officer with the U.S. Air Force. He currently serves on the

National Committee on Uniform Traffic Control Devices. He is a Professional

Engineer in the State of Utah.

Ed Fischer is the State Traffic Engineer for the Oregon Department of

Transportation. In this position he is responsible for providing Statewide policies and

guidelines for all traffic control devices; preparing traffic signal, illumination, signing

and pavement marking design plans for State highway projects; providing technical

analyses for operational and safety improvements on all State highways; managing

Statewide priorities for safety improvements and traffic signal installations; and

providing assistance and traffic engineering information to the public, the State

legislature, and other state and local agencies. While on this scan tour Ed was the
80

APPENDIX A

Regional Transportation Management Engineer for FHWA’s Pacific Northwest

Region. He has a Bachelor and Master of Science degrees from Oregon State

University. He is a registered Professional Engineer active on several committees of

the ITE, TRB and ITS-America.

Gene Hawkins, the Team Reporter, is an Associate Research Engineer and Program

Manager at the Texas Transportation Institute (TTI) of the Texas A&M University

System in College Station, Texas. At TTI he supervises and conducts transportation

engineering research with an emphasis on driver communication through traffic

control devices and freeway operations. Much of his research is focused upon various

aspects of traffic signing. Dr. Hawkins has developed extensive expertise of the

evolution of traffic control and the Manual on Uniform Traffic Control Devices and

has published several articles on the history of that document. Dr. Hawkins holds

three Civil Engineering degrees (Ph.D., M.E., B.S.) from Texas A&M University and is

a Registered Professional Engineer in Texas. He is also an active participant in

several national organizations including the National Committee on Uniform Traffic

Control Devices, the Transportation Research Board, the Institute of Transportation

Engineers, and the Highway Innovative Technology Evaluation Center. He is a

member of committees in each of these organizations.

Mark Kehrli is the Team Leader of the FHWA’s Office of Traffic Management and

ITS Application’s West Program Delivery Team which is responsible for aggressively

supporting implementation of traffic management and traveler information services

and strategies in FHWA’s Region 8 (Colorado, Utah, Wyoming, North Dakota, South

Dakota and Montana), Region 9 (California, Arizona, Nevada and Hawaii) and Region

10 (Washington, Oregon, Idaho and Alaska). Prior to his current assignment, he was

the Regional Transportation/ITS Engineer for FHWA’s Region 9. Before coming to

FHWA in 1995, he worked for the New York State Department of Transportation for

11 years as a Traffic/ITS Engineer and has significant experience in the design,

construction, operations/management, and maintenance of traffic control systems. He

has a Masters of Engineering degree in Transportation Engineering from Rensselaer

Polytechnic Institute and a Master of Science degree in Public Administration from

Russell Sage College. He is a licensed Professional Engineer and a member of the

Institute of Transportation Engineers.

Pete Rusch is the State Traffic Engineer for the Wisconsin Department of

Transportation in Madison, Wisconsin. In this capacity he is responsible for the

development of traffic engineering policy and standards for the design, use, and

application of traffic control devices on Wisconsin’s highways and for the regulation

and control of traffic. Mr. Rusch has over 30 years of experience as a practicing Traffic

Engineer within the Wisconsin Department, the last 6 years as State Traffic

Engineer. Mr. Rusch is a member of several national transportation organizations. He

is the Department’s representative to the AASHTO Traffic Engineering Subcommittee, is a member of the AASHTO Standing Committee on Highway Traffic, and

is a member of the National Committee on Uniform Traffic Control Devices. Mr.

Rusch has also been an active participant on several NCHRP project panels including

serving as the chair of the project Improve Traffic Control Devices for the Aging

Driver. In Wisconsin, Mr. Rusch is a member of the Governor’s Task Force on Highway
81

APPENDIX A

Traffic Safety and several other task forces with traffic safety as a key emphasis area.

He is a registered Professional Engineer in Wisconsin.

Scott Wainwright is Chief of the Division of Traffic and Parking Services for

Montgomery County, Maryland. He is responsible for all traffic engineering and

public parking functions for this major suburban jurisdiction of 800,000 population in

the Washington D.C. area. In this capacity, he sets policies and procedures for the

design, installation, maintenance, and operation of all traffic control devices on over

2400 miles of county streets and highways. Mr. Wainwright has 29 years of experience

practicing traffic engineering with operational public agencies. He has a B.S. degree

in Civil Engineering from Virginia Polytechnic Institute and State University and an

M.S. degree in Civil Engineering from the University of Connecticut, and is a licensed

Professional Engineer in Maryland. Mr. Wainwright is serving a 3-year elected term

as District 2 Director on the Institute of Transportation Engineers (ITE)

International Board of Direction. He has been in ITE, TRB, and other professional

organizations, authoring technical papers and textbook chapters, as well as serving on

panels related to traffic controls. He is a longstanding member of the National

Committee on Uniform Traffic Control Devices (NCUTCD) as an ITE delegate and is

the Chairman of the Signal Technical Committee of NCUTCD.
82

APPENDIX A
83

Appendix B

AMPLIFYING QUESTIONS

The following topics and questions identify the key issues of interest to the scan team.

They are intended to serve as a general guide to the host agencies in determining

which technologies, devices, and systems to demonstrate to the team. Since the team

members are not aware of all aspects of traffic control in the host agencies, the host

agencies may want to identify other devices and technologies that the team might be

interested in. These should be coordinated through the liaison contacts.

I. TRAFFIC CONTROL DEVICE SYSTEMS

A. There are some basic philosophical differences between European and U.S.

approaches to highway transportation and traffic control. The team is aware of

many of these differences, but would like the host agencies to summarize the

basic objectives of their traffic control device systems, particularly as they

relate to innovative traffic control devices and technologies.

B. Please provide team members with the key document(s) that establish the

basic principles for communicating information to drivers, if such documents

exist.

1. The major document(s) of interest is the one that establishes the basic

principles for traffic control devices. (In the United States, this document is

the Manual on Uniform Traffic Control Devices.)

2. Other documents that establish basic principles for specific applications

(such as changeable message signs or in-vehicle signing) are also of

interest.

3. It may also be helpful to see documents or brochures that are used to

educate or inform drivers of new applications of innovative traffic control

devices or technologies.

4. If any countries have performed evaluations of sign sheeting and/or

pavement marking materials, it would be helpful to get copies of the

reports so that they can be compared to our test results.

C. Have you implemented innovative technologies that are improvements to the

traditional types of traffic control devices (signs, markings, and signals)?

D. How are innovative traffic control devices and technologies being used to

integrate traffic control information on all modes of transportation (passenger

cars, transit vehicles, trucks, trains, bicycles, and pedestrians)?

E. What provisions have European national and state transportation agencies

taken to ensure/improve uniformity between innovative traffic control devices

and technologies used in different agencies?

1. How do you promote uniformity between jurisdictions in the operational

aspects of the systems?
84

APPENDIX B

2. How do you tie together applications of innovative traffic control

technologies to form a coordinated system for presenting information to the

driver?

3. How do you coordinate the presentation of information to drivers so that

they have a seamless system (consistent presentation format) as they

travel from one jurisdiction to another?

4. How do you address the language differences between countries as it

relates to the presentation of information to drivers?

5. How do local agency applications of innovative traffic control relate to

national applications?

II. REAL-TIME TRAFFIC CONTROL

A. Does your agency utilize real-time traffic control devices to convey information

to drivers about any of the following conditions?

1. Work zones or construction affecting traffic flow.

2. Weather (fog, rain, snow, ice, or other).

3. Traffic congestion and recommendations for alternate routing.

4. Driver alerts to prevent run-off-road accidents.

5. Availability of parking at specific locations.

6. Travel time for specific segments of a roadway.

B. In providing real-time information, how does your agency perform the

following?

1. Collect the information.

2. Determine the most effective means for presenting the information.

3. Communicate the information from the point of origin to point of

presentation.

4. Coordinate the information from various transportation modes.

C. What technologies have you found to provide the most effective means of

presenting the information to drivers?

D. How have transportation agencies responded to the increasing use of personal

communication technologies (such as cellular telephones, pagers, and invehicle navigation systems)?

E. Have you implemented any in-vehicle technologies for providing real-time

traffic control information?

1. What steps have you taken to ensure/improve uniformity between invehicle communication devices and roadside traffic control devices?
85

APPENDIX B

2. What inter-connecting systems do you use to tie traffic management

centers to in-vehicle communication systems?

F. How is the private sector involved in communicating real-time information to

drivers?

III. SAFETY ASPECTS

A. What innovative traffic control devices and technologies have been

implemented with the specific intent of improving safety (reducing the

frequency and/or severity of accidents)?

B. How do you assess the effectiveness of these applications?

C. How do you provide for driver education, driver familiarization, and driver

utilization of innovative traffic control devices and technologies?

D. Are you using photo-enforcement to improve driver compliance with traffic

control devices?

1. If you are, what has been the public acceptance of this type of enforcement?

IV. VERY HIGH SPEEDS

A. What provisions or accommodations do you make when implementing traffic

control devices on highways with very high speeds (100 km/h and higher)?

B. How have you utilized innovative traffic control devices or technologies to

improve the effectiveness of traffic control devices on very high speed

roadways?

C. Does your agency use dynamic speed limits on any of its roadways?

1. How do you determine and establish dynamic speed limits?

2. How is this information presented to drivers?

3. Is it regulatory or warning information?

D. What special provisions, if any, do you make for the design and operation of

traffic signals on very high speed roadways?

V. VISIBILITY AND LIGHTING

A. Please describe technologies and practices you have implemented to improve

the visibility and legibility of traffic signs and changeable message signs.

B. How have you used innovative traffic control devices and technologies to

improve the visibility of work zone traffic control?

C. How have headlight technologies affected the use of innovative traffic control

devices and technologies?

VI. ADMINISTRATIVE ISSUES (information for managers and policy makers)

A. How have you addressed the following aspects of implementation of innovative

traffic control devices and technologies?
86

APPENDIX B

1. What have you done to encourage public use of the various innovative

traffic control devices and technology applications?

2. How do you assess the effectiveness of innovative traffic control devices

and technologies both before and after implementation?

3. How do you address the issue of providing effective systems using low-bid

equipment?

4. What problems have been associated with the implementation of

innovative traffic control devices and technologies?

B. How does your agency prioritize innovative traffic control devices and

technologies projects for competing needs?

1. What problems has your agency encountered with the training and

retention of the qualified staff needed to implement and operate innovative

traffic control devices and technologies?

C. How has the private sector been involved in the development and

implementation of innovative traffic control devices and technologies?

1. Are systems financed by means other than by the government agencies?

2. How are the auto manufacturers involved in the use of in-vehicle

communication systems?

3. What role has the private sector played in the deployment of the roadside

infrastructure for major European implementation.

D. Have any particularly successful methods been used to educate elected

officials and policymakers on the importance of traffic control devices and the

need for priority in funding operation and maintenance of these devices?

E. What experience have you had with implementing innovative traffic control

device systems over large and significant segments of highway?
87

Appendix C

CONTACTS IN HOST COUNTRIES

The following pages list the names of the individuals that the team met with during

the trip. The team members wish to express their sincere gratitude to these

individuals for their time and the valuable information they provided to the team.

The listings are presented in alphabetical order.

ENGLAND

Highways Agency

Bob Bannon

Ian H. Beck

Joe Burns

Robert Castleman

Richard Eastman

Brian Harbord

Ian Harrison

Ken Hewitt

John A. Kerman

Hugh Maxwell

B.S. Moore

David J. Pike

John Robinson

Terry Sullivan

Bill Wadrup

Andrew Wilson

City of Birmingham

Paul Welsh

FRANCE

COFIROUTE

Jean-Pierre Boudin

Guy Frémont

Philippe Garnier

Olivier Grillot

Claude Humblot

Mairie de Paris (City of Paris)

Gérard Briet

Murièle le Marquand

Service dEtudes Techniques des Routes

et Autoroutes (S.E.T.R.A.)

Anne-Marie Barc

Gilbert Batac

Jocelyne Le Boudec

Claude Caubet

Francois Perret

Joëlle Villanneau-Hamel
88

APPENDIX C

GERMANY

Bundesministerium für Verkehr (Federal

Ministry of Transport)

Jürgen Behrendt

Stefan Drause

Elvira Kretschmer-Bäumel

Walter Kretschmann

Hans Mundry

Bundesanstalt für Straßenwesen (BASt)

Fritz Bolte

Peter Krieg

Hans-hubert mesebert

Sylvia Piszczek

Wolfgang Schulte

Roland Weber

Hessisches Landesamt für Straßen- und

Verkehrswesen (Hessen)

Rolf Andree

Gerd Riegelhuth

Tegaron

Wolfgang Behnck

Roman Eiber

WDR (West Duetsche Rundfunk - Radio

Station)

Uwe Platzek

SWEDEN

Enator

Lars Jernbäcker

Institutet för Transportforsknig

(Transport Research Institute)

Jan Arfwidsson

Mobiplan

Hans-Åke Pettersson

Vägverket (Swedish National Road

Administration)

Torbjörn Bidding

Fredrik Davidsson

Stefan Eglinger

Philip Gustafsson

Susanne Planath

Bengt Anders Wiklund

City of Gothenburg

Kjell-Arne Hellden

Anders Kåbjörn

Hans-Ake Pettersson

Claes Westberg

Electroswede Co.

Henrik Lewerntz

PEEK

Michael Severs
89

Appendix D

PROBLEM STATEMENTS

The following pages contain problem statements developed by team members. These

problem statements address some of the most significant recommendations contained

in this report. Team members are willing to assist individuals in developing other

problem statements that relate to issues described in this report or in modifying the

problem statements in this appendix to meet the needs of an agency.
90

APPENDIX D

PROPOSED RESEARCH PROBLEM STATEMENT

I. PROBLEM TITLE

Review of Temporary and Long-Term Pavement Markings Practices

II. RESEARCH PROBLEM STATEMENT

One of the most notable differences in traffic control devices between the United

States and Europe is how pavement markings are used. Recent scanning team

members observed marking applications in all four countries and found numerous

differences, especially in the use of color, work zones, horizontal messages, center line

and edge line use, symbols, merging, diverging, intersection control, and pedestrian

warning. The lack of yellow centerline median edge line pavement markings in

Europe was very obvious. Differences in stripe/gap ratios were also observed between

center lines and lane lines. Team members were impressed by many other pavement

marking applications that are not extensively used the U. S. roadways. Examples

include highway numbers(s) in the lane(s) in advance to the indicated highway; STOP

and Yield markings at intersections and roundabouts; markings that indicate parking

prohibitions; lane marking carried through the intersections; and multilane entrance

ramp marking.

III. RESEARCH OBJECTIVES

Conductive an in-depth review of the pavement marking practices used in the U.S.

and Europe for both long-term and temporary applications. This review shall seek

research supporting information on their effectiveness in controlling and managing

traffic, how easily they are understood by drivers, and the overall effect they have on

driver behavior.

IV. ESTIMATE OF PROBLEM FUNDING AND RESEARCH PERIOD

18-months; $150,000

V. URGENCY, PAYOFF POTENTIAL, AND IMPLEMENTATION

The FHWA Office of Highway Safety is in the process of rewriting the Manual on

Uniform Traffic Control Devices (MUTCD) to propose changes that will enhance the

mobility and safety of all road users, promote uniformity of traffic control application,

and incorporate technology advances in innovative traffic control. The data gathered

from this NCHRP study will provide a basis for including MUTCD standards for the

use of pavement markings. The urgency of this study is also recognized because of the

environmental issues associated with the use of certain types of pavement marking

materials.

VI. PERSONS DEVELOPING THE PROBLEM STATEMENT

Linda L. Brown, FHWA Office of Highway Safety
91

APPENDIX D

PROPOSED RESEARCH PROBLEM STATEMENT

I. PROBLEM TITLE

Variable Speed Limit and Dynamic Lane-Use Control Signs

II. RESEARCH PROBLEM STATEMENT

Vehicle travel is increasing throughout the world, particularly in large urban areas.

Accommodating the increased travel demand has led transportation officials to utilize

a variety of innovative traffic control practices. Today’s information age and

technology advancements have raised the level of expectation of our road users and

created much more savvy drivers. Road users have come to expect more and more

from the highway system: more information, more options, and more quality of

service. The challenge for transportation officials is to provide more real-time

information to the road users. Providing real-time information through dynamic/

variable message signs has the potential benefit of making our highways safer and

more user-friendly, and warrants consideration.

In May of 1998 a team of U.S. transportation officials visited four European countries

(Sweden, Germany, France, and England) to explore and identify traffic control

practices that may have current or future value to transportation agencies in the

United States. Dynamic variable speed limit signs were extensively used in Germany

and England to control traffic flow and improve safety. The speed limits are based on

real-time traffic speed and flow data provided by loop sensors used to detect forming

queues and slow moving vehicles occurring from incidents ahead. The speed limits are

changed to provide the road user with real-time information regarding the prevailing

traffic speed. This advance information provides the road user with more decision and

reaction time. In addition, the installation of the variable speed limit signs over the

travel lanes appears to improve the visibility of these signs from greater distances

than the static speed limit signs found along the side of the road. When there is not

an incident ahead, the variable speed signs are set at the normal advisory or

regulatory speed and serve as reinforcement messages to remind drivers of the safe

travel speed.

In addition to recommending an evaluation study for variable speed signs, dynamic

lane-use control signs are also recommended for inclusion in this study. Overhead

lane-use control signs help inform road users of the traffic conditions downstream. A

red X designates lane closure situations, a yellow or white diagonal arrow designates

lane merge situations, and a green down arrow designates open lanes.

III. RESEARCH OBJECTIVES

1. To determine what factors drivers use to determine the appropriate speed.

2. To determine if variable speed limits and lane-use signs smooth traffic flow and

reduce rear-end collisions.

3. To determine if providing this type of real-time information helps improve driving

tasks such as lane changing, sudden stops, and other erratic maneuvers.

4. To determine if the design and location of these signs improves sign visibility.
92

APPENDIX D

5. To study the merits of photo enforcement cameras used in conjunction with

variable speed limit signs.

Tasks:

1. Review and critique available literature pertaining to variable speed limit signs

and dynamic lane-use control signs used for providing real-time information to road

users.

2. Convene a panel of experts including representatives from traffic engineering, law

enforcement, judiciary, MPOs, DMVs, and human factors.

3. Develop comprehensive work plans and measures of effectiveness to determine

the potential benefits.

4. Conduct controlled field studies to determine the impact and reactions of drivers,

particularly older and younger drivers.

5. Prepare a public awareness effort to inform road users of the potential benefits,

and promote the innovative technology.

IV. ESTIMATE OF PROBLEM FUNDING AND RESEARCH PERIOD

The estimated funding for this project is $750,000. The research is expected to take 36

months to complete.

V. URGENCY, PAYOFF POTENTIAL, AND IMPLEMENTATION

The FHWA Office of Highway Safety is in the process of rewriting the Manual on

Uniform Traffic Control Devices (MUTCD) to propose changes that will enhance the

mobility and safety of all road users, promote uniformity of traffic control application,

and incorporate technology advances in innovative traffic control. The data gathered

from this NCHRP study will provide a basis for including MUTCD standards for the

use of dynamic message signs, particularly in the area of speed and lane-use control.

The anticipated date for publishing the next edition of the MUTCD is September

2000.

VI. PERSONS DEVELOPING THE PROBLEM STATEMENT

Linda L. Brown, FHWA Office of Highway Safety
93

APPENDIX D

PROPOSED RESEARCH PROBLEM STATEMENT

I. PROBLEM TITLE

Software to Reduce Dilemma Zone at Signalized Intersections

II. RESEARCH PROBLEM STATEMENT

In a recent FHWA Scanning trip to Europe, the team was briefed in Sweden on a

system they had developed to improve intersection safety. The system was based on a

sophisticated system of detection and traffic signal controller logic which enables the

change in right-of-way between opposing traffic movements to be based on assessing

and minimizing the safety risks for traffic on the approaches which will be stopped. It

is a dilemma zone enhancement which translates stopping risks and cross street

queue development to a cost algorithm. Safety is a specific consideration in the

control logic process. The objective is to reduce rear-end collisions by finding the

perfect gap for the signal phase to terminate. This may be a useful application at

high-speed U.S. intersections

III. RESEARCH OBJECTIVES

The objective of this effort is to assess the technical feasibility of using this type of

intersection control to improve intersection safety, estimate the cost/benefit potential

of the application, estimate how many U.S. accidents and fatalities could be prevented

with this application, and determine if a field operational study should be initiated

(under a separate effort).

IV. ESTIMATE OF PROBLEM FUNDING AND RESEARCH PERIOD

The estimated funding for this project is $100,000. The research is expected to take 18

months to complete.

V. URGENCY, PAYOFF POTENTIAL, AND IMPLEMENTATION

VI. PERSONS DEVELOPING THE PROBLEM STATEMENT

Sam Tignor, FHWA Office of Safety and Traffic Operations R&D
94

FHWA INTERNATIONALTECHNOLOGY EXCHANGE REPORTS

Highway Information Management

National Travel Surveys (September 1994)

Traffic Monitoring (June 1996)

National Personal Transportation Studies (October 1993)

Acquiring Highway Transportation Information from Abroad—Handbook (1994)

Acquiring Highway Transportation Information from Abroad—Final Report (1994)

Intermodal Transportation

European Intermodal Programs: Planning, Policy and Technology (September 1994)

Pavement

Highway/Commercial Vehicle Interaction (1996)

South African Pavement and Other Highway Technologies (May 1997)

European Asphalt (1990)

European Concrete Highways (1992)

Policy

International Contract Administration Techniques for Quality Enhancement—

CATQEST (June 1994)

Safety

Pedestrian and Bicycle Safety in England, Germany and the Netherlands (October 1994)

Bicycling and Walking in the Nineties and Beyond (1994)

Highway Safety Management Practices in Japan, Australia, and New Zealand (June 1995)

Speed Management and Enforcement Technology (February 1996)

Road Safety Audits—Final Report (October 1996)

Road Safety Audits—Case Studies (October 1996)

Structures

Geotechnology—Soil Nailing (June 1993)

European Bridge Structures (1996)

Northumberland Strait Crossing Project (July 1996)

Bridge Maintenance Coatings (January 1997)

Advanced Composites in Bridges in Europe and Japan (October 1996)

Geotechnical Engineering Practices in Canada and Europe (March 1999)

Research and Development

Scanning Report on Advanced Transportation Technology (December 1994)

Snowbreak Forest Book: Highway Snowstorm Countermeasure Manual

(Translated from Japanese)

To order copies of these reports online, contact: international@fhwa.dot.gov

Or contact: Office Of International Programs

FHWA/US DOT (HPIP)

400 Seventh Street, SW, Room 3325

Washington, DC 20590

Tel: 202-366-9636

Fax: 202-366-9626

You can read select documents on our website: www.international.fhwa.dot.gov

NOTES
NOTICE

The contents of this report reflect the views of the authors, who are responsible for the facts

and accuracy of the data presented herein. The contents do not necessarily reflect the official

policy of the Department of Transportation.

The metric units reported are those used in common practice by the persons interviewed.

They have not been converted to pure SI units because in some cases, the level of precision

implied would have been changed.

The United States Government does not endorse products or manufacturers. Trademarks or

manufacturers’ names appear herein only because they are considered essential to the

document.

The publication of this document was sponsored by the U.S. Federal Highway Administration

under contract number DTFH61-99-C00005. awarded to American Trade Initiatives, Inc. Any

opinions, options, findings, conclusions, or recommendations expressed herein are those of

the authors and do not necessarily reflect those of the U.S. Government, the authors’ parent

institutions, or American Trade Initiatives, Inc.

This report does not constitute a standard, specification, or regulation.

Office of International Programs

FHWA/US DOT (HPIP)

400 Seventh Street, SW

Washington, DC 20590

Tel: 202-366-9636

Fax: 202-366-9626

international@fhwa.dot.gov

www.international.fhwa.dot.gov

Publication No. FHWA-PL-00-021

HPIP-10/8-99(6M)EW
NOVATIVE TRAFFIC CONTROL  Technology and Practice in Europe