ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDAZONAL IMPACT ANALYSIS OF A STRATEGICPLANNING APPROACH FOR LAND DEVELOPMENTCONTROLS– A Case Study of Bangkapi, Bangkok –Karin LIMAPORNWANITCH

Kardi TEKNOMO

Department of Civil Engineering, Saga University, Saga, Japan

Institute of Lowland Technology, Saga University, Saga, Japan

Kazunori HOKAO

Atsushi FUKUDA

Professor
Department of Civil Engineering, Saga University
Saga, Japan

Professor
College of Science and Technology, Nihon University
Chiba, Japan(Received April 14, 2004)

Due to rapid urban developments in developing cities, the integration of land-use and transportation planning is very necessary. However, upto-date land-use and transportation interaction planning is still difficult, because of rapid urbanization and complex relationships. The lack of humanresources, budget, and necessary data are some of the hindrances. The planners in Bangkok have tried to utilize Traffic Impact Assessment (TIA) inharmonizing land developments and transportation improvements, but without a complete land-use comprehensive plan, the TIA cannot effectively
manage urbanization. This paper intends to propose a Zonal Impact Analysis (ZIA) framework as a strategic planning tool to balance travel demandsof land developments and performance of transportation systems over urban areas. First, the land-use planning situation in Bangkok is explained,
afterwards the framework is described. The framework is applied into Bangkapi areas as a case study. Both single and simultaneous development
cases are considered. It was found that more comprehensive development alternatives were established. The most suitable zone for a single project
is Zone 179, as the advantages of location in the center of radial networks, so full accessibility can be provided. Without any network improvements in
Zone 179, the simultaneous developments should be implemented in Zone 168 and 173, as high capacities of the expressway are available. The
results give a better understanding on the characteristics of land-use and transportation planning in Bangkapi. Finally, it was emphasized that the ZIA
framework is a strategic planning alternative to increase the capabilities of growth management for sustainable developments.
Key Words: Traffic impact, Impact assessment, Zonal Impact Analysis, Land-use control, Strategic planning approach

1. BACKGROUND
The transportation improvements and land-use controls of mega-urban regions in developing countries havenot kept pace with the economic and urbanization growthfor years. It has been pointed out that in developing cities urbanization is very rapid and dramatic, so the integration of land-use and transportation planning is very
necessary1. However, up-to-date the interdependence ofurban forms and transportation networks are still ignored
in Southeast Asian cities like Bangkok, Jakarta, and Manila1-3. Particularly in the Bangkok Metropolitan Region(BMR), because the gross region domestic product percapita (GRDP) had increased from 1978 to 1988 as
shown in Figure 1, it resulted into the growth of population, and the expansion of urbanized areas (see Figure 2).
From Figure 2, it can be seen that the areas within
2.5 km from the city center were saturated, the numberof people in this area have increased at a very small ratearound 0.1% during 1980 to 1986. In the opposite, thepopulation of districts in the vicinity and suburb an areas were still increased at a rather high rate of about 24%. This tendency represents the suburbanization of
BMR, that residential areas and activity centers are moving into the suburbs. Although, during the period of theeconomic crisis, 1997 – 2002, the urbanization processof Bangkok slowed down, after 2002 the growth has beenstimulated again. Based on various development projects
without any control strategies in suburban areas, Bangkok
has become an auto-dependent city with severe traffic
congestion spread from its core to suburban districts. This
paper aims to propose an alternative strategic planningapproach, the Zonal Impact Analysis (ZIA) model, to balance travel demands of land developments and performance of transportation systems over urban areas. First,
the land-use planning situation in Bangkok is explained,
and followed by the concept of the ZIA framework. SecIATSS RESEARCH Vol.28 No.2, 2004 •55

TRANSPORTATION

300

90.00

1970
1980
1986

275

Population density (people/ha)

Gross ragional domestic productper capita (Baht thousands)

100.00

80.00
70.00
60.00
50.00
40.00
30.00
20.00

250
225
200
175
150
125
100
75
50

10.00

25

0.00
1978 1979 1980 1981

1982 1983 1984 1985 1986 1987 1988
Year

–30

–15

–7.5

–2.75

0
–1.25

1.25

2.75

7.5

15

30

Distance from the city center (Km)Fig. 1 Trends of increase of GRDP for BMR in 19781988

Fig. 2 Population growth for BMR urbanization in
1970s-1980s

ond, the framework application is described through acase the study of the Bangkapi area. Finally, the resultsof study are discussed and summarized in the conclusion.

opment project can be officially approved as long as it
does not violate the basic rules, including structurally safe
standards in the Building Control Law, types of land-use
prohibited by the City Planning Law. The existing rules
for planning tools can only control the project as part ofthe building control system focusing on the building
rather than its location that is a very important factor4.
At present, it is under the Ninth plan (2002-2006), its goal
is to decentralize the Bangkok Metropolitan Area into
suburban areas like a polycentric city. It can be noticed
that most specific contents of each plan in each period
are insignificantly different, therefore the weak points offormer plans cannot be significantly improved in the latter ones. To coordinate transportation improvements andland-use developments, most transportation projects refer to the land-use zoning plan provided in the comprehensive land-use planning process of BMA as shown
Figure 3.
From the process, it is noticed that the transportation components are included into the land-use planningsteps as an inactive element. The effects of land-use
changes on transportation systems, especially in terms oftrip generation, are not taken into account. It can be perceived that the comprehensive plan of BMA is planned
without a systematic and analytical approach for transportation components. Any land-use types or regulations
mainly come from the consideration of existing conditions, such as the existing land-use characteristics, physical environment of networks etc. The outcomes of thisplanning approach can be satisfied, if the city growth isnot so rapid, and the relationship of urban structural components are not complex. However, this is inappropriate
for swift urbanization and complicated interactions of the
BMR. It cannot analyze the transportation capabilities in

2. LAND-USE AND TRANSPORTATIONPLANNING IN BANGKOK
Land-use and transportation planning for Bangkok
were principally integrated for the first time in the Seventh National Economic and Social Development Plan
during 1992-1996. Under this plan, any new development
project in Bangkok had to be controlled by the Enhancement and Conservation of National Environmental Quality Act of 1992. This means that the owner of adevelopment project that has a number of parking lots ofmore than 300 parking units or gross floor areas larger
than 2,000 square meters must conduct an environmental impact study, and submit a report to the Building Control Division (BCD) of the Bangkok Metropolitan
Administration (BMA). The developer has to mitigate theadverse development impacts based on the suggestionsof BCD for the project approval.
However, the Seventh plan was unsuccessful, due
to the fragmentation of the responsibilities of the agencies concerned with: road building, infrastructure program, housing, and land-use plans. In fact, the inefficientplan and ineffective enforcement were also the main reasons for fruitlessly implementing the land-use controls.
The plan has little or no control over the intensity of development nor does it suggest the meaningful ranges ofdensity in each area or type of land-use. Worst of all, regardless of the size and location of a project, any devel-

56 • IATSS RESEARCH Vol.28 No.2, 2004

ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDA

Identify the areas,
goals and objectives

Data Collection
Physical Conditions
Socio-economic conditions
Populations

➢➢➢

➢➢➢

Field Survey
Land usage and Buildings
Transportation Characteristics
People’s opinion in the surrounding areas➢➢ ➢➢➢

Data Analysis
Report the results of study
Table
Map
Figures
Graphs➢➢Identify the strategy of land use plans
Consider to enact land use regulations+ The Bangkok Administration Act
Refer to the land use rules+ Identify the zoning regulations+ Identify the land use rules- Setback- Spacing between buildings- Type of buildings or activities- Height of buildings- Number of stories- FAR, BCR, OSR- Lot size
- Open space

The Final Land Use Plans

Fig. 3 The process of developing a comprehensive land-use plan in Bangkok

serving the land developments in each area. Particularly,
when the government plans to expand Bangkok into suburban districts, it may be leading more ribbon developments along the main routes, and creating more super
block areas in the city.
It is realized that to efficiently perform the integration of land-use and transportation planning, their interactions ought to be deliberated through advanced
simulation techniques. However, in developing cities,
such as Bangkok, Manila, and Jakarta, their urban growthis so rapid and complex, because of high density mixed
land usages, hence it is very intricate to do so. In addition, there are the limitations of lack of human resources,
budget, necessary reliable data 1. The recent progress ofland-use and transportation planning integration in devel-

oping countries are the challenges of traffic impact assessment (TIA) applications6,7.

3. ZONAL IMPACT ANALYSIS:A STRATEGIC PLANNING ALTERNATIVE FOR
LAND-USE AND TRANSPORTATION PLANNING
As explained before, the comprehensive land-use
planning process in Bangkok neglects to systematicallydetermine the land-use effects towards the transportation
performances in each area. This leads to omit the basic
land-use control rules about types and densities of buildings, which can have significant effects on traffic. Some
IATSS RESEARCH Vol.28 No.2, 2004 •57

TRANSPORTATION

examples of existing basic rules are limits on floor area
ratio, building setback, plot size, and spacing of entrance
or exit from the properties to main roads. To cope withthe development densities, only the basic rules about giving the allowable percentage of non confirming use within
any zone is utilized, for example in a commercial area,other uses are limited to increase up to 10% of the total
area for each of them. There is no mention of a trafficplan in the comprehensive plan, or no serious concerns
about the network capability carrying travel demands ina developed area.
The direction of land-use developments and transportation improvements in developing countries is ambiguous. Most actions in their planning skills are justtrying to apply some successful practices from other developed countries into those countries without a systematic planning process. Similar to the applications of TIA
in Bangkok, although planners attempt to employ it tobalance between travel demands and facility capacities,
but they will not be able to avoid the situation of demand
exceeding supply over urban areas. As the TIA concentrates on a site specific impact analysis, it cannot examine
the harmonization of land-use developments and transportation performance at the macro level or whole urban
area. It is pointless to discuss the lack of TIA standards,
experts, and rigorous enforcements in Bangkok. For developed countries, the TIA can function well to mitigate
the negative impacts of a project, because they have very
complete comprehensive land-use plans, and also strong
regulations and enforcement. Therefore, what the planners in developing countries urgently need is a strategicplanning tool to develop their complete comprehensive
land-use plan.
3.1

A strategic planning approach: Zonal Impact
Analysis model
Generally, strategic planning is defined as a set ofconcepts, procedures, and tools designed to help planners
or decision makers think and act strategically8. To improve the comprehensive land-use plan at the macro levelof BMR planning, the strategic planning approach is vital. This paper intends to propose an alternative tool ofstrategic planning approach, Zonal Impact Analysis(ZIA) framework, to systematically control or design theland-use into the desired direction of sustainable development cities.
The ZIA framework, as shown in Figure 4, aims toassess the effects of land developments on the networks
in each zone. It can aid planners to know the development
capacities in each area, and limit their suitable sizes or

58 • IATSS RESEARCH Vol.28 No.2, 2004

types of development. Furthermore, the ZIA framework
is designed to evaluate not only traffic impacts, but theirsecondary impact, including environmental and economic
impacts. The framework is separated into four parts, consisting of land-use development directions, transportation
network database system, zonal impact assessment, andevaluation of land development alternatives. The detailsof each part can be described as follows:
The land-use development directions: This partconsiders the performances of land development in eachurban zone based on the zonal characteristics, including
available spaces, population, the existing infrastructureetc. All zones should be included in the evaluation to investigate the direction of land development. The necessary data, including land-use, travel, and socioeconomic
data, is in the zonal base, an existing data format of urban planning databases for most metropolitan cities. In
this case, the data acquisition is not costly compared tothe establishment of a new database system. Moreover,the national and regional plans should be considered asa basic direction to provide a consistent plan with thesame development goal. For example, the decentralization of Bangkok is the main policy at present, thus the
directions for developing each suburban center must be
considered to know which parts of the city have the development potential in the future. The type, size, andother characteristics of land-use projects must be considered based on the real situation. All possible tendencies
should be included in the analysis.
The transportation network database system:
The transportation database system usually is prepared forthe whole city area, not for the zone-bases. To appraise
the zonal impact, planners need to rearrange existing databases into the zone-base formats. The total networks
have to be classified and kept into the zones where they
are located. Eventually, the new databases can represent
which zone occupies which parts in the total network. The
present conditions of urban travel characteristics in the
study area, including Origin-Destination (O-D) distributions, mode splits etc., are utilized as the base case in theimpact assessment process. According to the previous
step, the expected development projects appraise the effects on the transportation systems, such as trip generation and distribution for the project. The traffic
simulations for the base case (or without development
project) and with project cases are performed to evaluate the impact.
The zonal impact assessment: The traffic impact,
such as vehicle-delays, vehicle-kilometers, etc., are quantified in this step by considering the zonal level. Next,ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDA

Land Use Development Directions
Evaluate the development
performance of all zones
available spaces, population,
existing infrastructures, etc.

Consider with land use plans
and regulations in zones
allowable project type and size,
the basic rules, including setback,plot size, etc.

Selected High Potential Zones

Selected Development Projects

Transportation Network Database System
Network database forwhole urban areas- networks- trip characteristics- socio-economic data

The effects of landdevelopments on network- trip generation- trip distribution- mode splits

The existing networks andtrip characteristics in zone-base(for the base case)- O-D trip patterns- trip characteristics

Simulation Model: Strategic
Transportation Planning Program

Prepare networks for highpotential zone
- networks for each zone
(in zone-base)

Zonal Impact Assessment
Economic cost estimation models- vehicle operating cost models- average car occupancy, time value

Environmental pollution
prediction models- air pollution models- noise pollution models

Traffic impact
volume, veh-km,
speed, delays, etc.

Environmental impacts- air pollutions (CO, SOx, NOx)
- noise pollution

Economic impacts- vehicle operating costs- travel time costs

Evaluation of Land Development Alternatives
The Impact Evaluation and Analysis
The Development of Comprehensive Land Use Plan based on
Transportation Capabilities for Each Zone
Fig. 4 The framework of Zonal Impact Analysis (ZIA) model

these traffic impacts are utilized into the processes of environmental and economic impact assessments. To evaluate both kinds of secondary impact, the inventory dataof essential models, parameters, basic information, suchas air pollution prediction models, vehicle operating costestimation model, and value of time, in the study area
must be collected and reviewed.

IATSS RESEARCH Vol.28 No.2, 2004 •59

TRANSPORTATIONThe evaluation of land development alternatives:
After the zonal impact assessment process, the results of
all cases are analyzed and compared to find an optimum
development alternative, which maximizes the social benefits or minimizes the social costs. Based on the selected
alternative, the comprehensive land-use plan can be performed to harmonize between land developments andtransportation capabilities for each area of a city. The undesired impacts, including more congestion, high travel
costs, environment degradation, should be diminished tolead the city into sustainable development.
To illustrate the application of the proposed ZIA
framework, a case study was conducted. The study wasapplied to Bangkapi District of Bangkok to illustrate how
to employ the proposed framework to improve the existing land-use planning by concerning transportation issues.
The details are explained in the next section.

4. THE APPLICATION OF THE ZONALIMPACT ANALYSIS MODEL:A CASE STUDY OF BANGKAPI AREA
This section aims to demonstrate the application of
the ZIA framework through a case study. The study area
includes the zones of Bangkapi and Wangthonglang districts. As these zones belonged to Bangkapi District before 1998, hereafter they were called Bangkapi area inthis paper. Based on the ZIA framework, the study is explained step by step. First, to analyze the characteristicsof the study area, its general information is reviewed. Thisintends to draw the present conditions of Bangkapi, andinvestigates the development potentials to represent future tendencies. The high potential zones are selected andanalyzed in the next step. Second, the samples of development projects are selected and their characteristics are
explained. To concern every development case, all possible analysis strategies are prepared and simulated by the
traffic simulation program. After the simulations, theirimpacts are quantified in the process of zonal impact assessment. Finally, the analysis of impact assessments is
conducted to interpret the results of the study.
This research mainly utilized the transportation database networks, geographical data, and socio-economic
data of BMR. The necessary data was available from the
Urban Transport Database and Model Development(UTDM) Project established in 1995, and the Transport
Data and Model Center (TDMC) Project in 2000. Moreover, the indispensable data of land-use planning were60 • IATSS RESEARCH Vol.28 No.2, 2004

also included in the analysis.
4.1

The background of study areas
The study areas are located in the middle of two development directions of BMR, the North and South-Eastdevelopment directions. They include Huamark,
Khlongchan, and Wangthonglang sub districts with areasof 16.461, 12.788, and 19.655 km2 respectively. There aremany main transportation facilities implemented, particularly for the Ramintra-Atnarong expressway, Ramkamhang,
Nawamin, Serithai, Srinakarin, and Ladproa roads. These
networks promote the Bangkapi areas to be a business andactivity center. Moreover, according to the Second Bangkok
International Airport Project, it significantly supports to urbanize the city from the core of Bangkok into the Bangkapi
area (see Figure 5).
Based on the databases of UTDM project, the study
areas were separated into 14 zones, and the populationfor each zone in 2003 was estimated in Figure 6. The total population of the study area is about 483,604 people.
The zoning system of Bangkapi area follows the existing transportation databases, both UTDM and TDMC
projects. The projects separated the sub districts from theland-use plan into the zonal level in order to perform theurban travel simulation. The current growth rate of population in the study areas is about 1.40% annually.
4.2

The land-use conditions of the study area
In Bangkapi, the agricultural areas and vacant
spaces are about 15.46% of the total area. This represents
that most of the Bangkapi area is dedicated for buildings
and activity areas as shown in Figure 7. The houses orvillages are the highest proportion of land usage, at about
3,734,668.05 m2 or 73.41% of the total activity area. The

Internal Study Area
External Study Area
Ramintra-Atnarong Expressway
Ramkamhang Road
Nawamin Road
Serithai Road
Srinakarin Road
Ladprao Road
Bangkapi Business Center

The Second Bangkok
International airport Project

Fig. 5 The location and transportation networks of
Bangkapi area

ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

second is for office buildings, about 1,080,560.75 m2 or
21.24%. The remaining includes the commercial houses,
industrial and store areas, and others. The land prices ofthese areas are gradually raised as the results of economic
benefits increase. By considering the location of
Bangkapi, and its infrastructure performance, it is believed that Bangkapi has full potential for land developPotential Zones for theDevelopment Projects

Zone 171
2753
Zone 172
17897
Zone 167
58219

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDA

ment. In particular, it can play the role as the transitionzone to connect between inner and outer Bangkok areasin the Eastbound approach9.
The main transportation networks in Bangkapi are
the arterial roads connected as a radial network by approaching the Bangkapi Business Center. These roads areconnected together by local roads and small streets in thearea. Based on the economic growth, many commercial
areas are expanded along main roads. Due to its own potential and the growth direction of BMR, the planners decided to develop the Bangkapi Business Center as the main
center in this area. They also proposed to develop thecommercial area along Ramkamhang road. These land de-Zone 168
47268
1
2
3

Zone 173
47712
Zone 175
68941
Zone 169
46211

Zone 170
28370

Zone 174
18150

Secondary Business Center Areas
Service Business Center Areas
Business Center Areas
Low Den. Residential Areas of Med. Rise
Low Den. Residential Areas of Low Rise
Medium Den. Residential Areas

Zone 17938201
2

Zone 177
2475

Zone 178
36684

Zone 176
60723

Zone 180
10000
Unit of Population: Person

Source: estimated from UTDM

3
1

Fig. 6 Populations in each zone and the location ofZones 168, 173, and 179
Residential Areas
Business Areas
Industrial & Store Areas

Ladprao District

Government & Public Health Offices
Educational Places

Source: DCP, 20029

Fig. 8 The land-use plan and transport networks of
Bangkapi area

Religious Places
Activity Places
Open Spaces

Desire Lines for OD Zone Pairs(Line sizes based on the scales)

Agricultural Places

Bangkapi District

Bangkapi Business Center
Pravet District

Source: DCP, 20029

Source: estimated from TDMC, 2000

Fig. 7 The existing land-use conditions in Bangkapi
area

Fig. 9 The O-D distribution in the internal areas of
Bangkapi area
IATSS RESEARCH Vol.28 No.2, 2004 •61

TRANSPORTATION

velopment plans of BMA can be illustrated in Figure 8.
4.3 The characteristics of the analyzed development
projects
To analyze the impact of development projects, thisstudy chose to consider a shopping center project as theanalyzed development project. Due to a lot of residents
living in Bangkapi area, many projects for shopping centers have been proposed by developers. The research conducted field surveys to investigate the possible locations
for development projects. In addition, the present characteristics of each zone, such as populations, present landuse conditions, provided infrastructure, available spaces
etc., were also considered to evaluate those possible locations. Eventually, there were three potential zones, including Zone 168, 173, and 179, selected fordemonstrating the ZIA application. As the consequencesof expanding transport networks, like the RamintraAtnarong expressway, it can be expected that the zones
next to this expressway, Zones 168 and 170, will be built
up in the future. Nonetheless, because of a large numberof people, only Zone 168 was selected for the analysis.
In fact, this zone is controlled as a low residential area,
but the land-use regulations in the study area are very
weak. As the exception, if a big commercial project can
provide the right of way from the main road more than
18 meters, the project can be approved by the administration. In addition, if in the area there is the proportionof such land-use project less than 10% of the total area,
the project can be approved. For Zone 173 and 179, because they are located in the promoted areas of Bangkapi
Business Center and also the direction of eastbound developments along Ramkamhang and Serithai roads, there
is no doubt to include them in the study.
Regarding the research of traffic generation of shopping center projects located in suburban centers of
Bangkok, the average trip generation rates for weekdays

and weekends were estimated about 2.92, and 3.36 pcutrips/100 m2/a day, respectively10. It was assumed that theanalyzed shopping center project occupies a service areaof about 200,000 square meters. From the field survey, it
was found that the critical period of the Bangkapi area, particularly for traveling to shopping or commercial areas, isthe evening peak hour of weekdays. Therefore, the study
conducted traffic simulations and impact assessments byconsidering the evening peak period on weekdays.
To cover all possible development cases, not only
the cases of single development in a single zone wereconsidered, but the cases of simultaneous developments,
often occurring in Bangkok and other developing Asian
cities, were also included as shown in Table 1. All simultaneous development cases referred to the same type andsize of project in order to determine the real effects oftransportation capabilities in serving travel demands ofeach zone. These cases were simulated and analyzed into
the steps of traffic simulations, and impact assessment andanalysis, respectively.
4.4

The traffic simulations of analysis cases
The traffic simulations were performed based on the
network and trip databases of the TDMC project. The
necessary network and trip data for the zones inside ofand surrounding Bangkapi area were provided as the datafor 14 internal and 13 external zones, respectively (SeeFigure 5). The transportation networks and the present OD trip distribution patterns of the internal areas of the casestudy are demonstrated into Figures 8 and 9. To simulate the present travel behaviors and the traffic generated
by the project, the Strategic Transportation Planning Program was developed and employed for this research. In
Table 2, it shows the simulated traffic indicators, including vehicle-kilometer (pcu-km/hr), vehicle-travel time
(pcu-hr/hr), average speed (km/hr), and total flows (pcu/

Table 1 The analysis cases of the Zonal Impact Analysis
Type
The Base CaseGroup
Without Project

Analysis Case

One Project

Zone 173—

Case No. 3—

Case No. 4
Simultaneous Developments

Two Projects—

Case No. 5—

Case No. 6—

Case No. 7
Three Projects
Note: — means that the development project implemented in the zone.

62 • IATSS RESEARCH Vol.28 No.2, 2004

Zone 179

Case No. 1
Case No. 2

Single Development

Zone 168

Case No. 8

—

—
—
—

—

—

—

ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDA

Table 2 The total traffic indicators of internal and external zones for eachanalysis case
Case

Vehicle-kilometer

Vehicle-travel Time

No. 1

749,397

98,9607.57

1,656,150

No. 2779,862

105,430

7.40

1,721,747

No. 3

764,493

103,3277.40

1,681,464

No. 4

753,372

99,1007.60

1,663,542

No. 5

756,046

99,492

7.60

1,669,236

No. 6

766,157

103,9747.37

1,687,941

No. 7

779,158

102,771

7.58

1,703,579

No. 8

784,528

106,995

7.33

1,747,249hr), for the whole study areas consisting of internal andexternal zones.
From the results, all development cases were increased in all indicators when compared to the base casewithout the project. This indicates that more trips weregenerated in the internal and external study areas, so traffic conditions in some areas become more congested.
Case No. 8 should be imposed by the most severe traffic
impact, as the new shopping center projects were implemented in all three zones. Although the numbers of vehicle-kilometers and vehicle-travel time in Case No. 4 and
5 were higher than in the base case, their average speedsof the total area could be improved from 7.57 km/h in
the base case to 7.60 km/h. This might be because thetraffic was reassigned in the networks more efficiently.
These traffic indicators were not only evaluated for thewhole area, but they were also performed in each zone
so that the zonal impact distributions could be evidently
considered. Particularly, they were utilized to estimate thezonal economic impacts caused by development projects
in the next step. However, this study mainly focuses on
the impacts of land developments in Bangkapi area, so
the economic impacts generated in only 14 internal zones
are estimated. The impact of external zones were neglectedin this article. Therefore, the traffic indicators and economic
impact of internal zones in each development alternative
might be increased or decreased from the base case.
4.5

The Zonal Impact Assessment for the development projects
The impacts are defined as the changes of traffic indicators in the network. The zonal impact of vehicle-kilometers, vehicle-travel time, and total flow can be estimatedas their summations from all links in a zone. For average
speed, it is averaged by travel distances and travel time ina zone. These impacts were used to estimate the secondary
economic impacts in the internal zones of Bangkapi area.

Average Speed

Total Flows

They included travel time and vehicle operating costs inevaluating development plan alternatives. To estimate theeconomic costs, the value of time and vehicle operating costestimation models developed by the Department of Highways (DOH), Thailand (2000)11 were applied in the study.
It was estimated that in 2003 the value of time for working
or educational trips, and non working trips are 59.603, and14.903 Baht/hour/person respectively. The average car occupancy rate for Bangkok was estimated at about 1.4 passengers/car. The distribution patterns of additional travel
impact costs for each zone can be illustrated in Figures
10(a)-10(g). In the figures, the impacts arranged into 5 levels, from very low (0-40,000 Baht/hour), low (40,00080,000 Baht/hour), medium (80,000-120,000 Baht/hour),high (120,000-160,000 Baht/hour), and very high impacts(160,000-200,000 Baht/hour), respectively. To find the suitable development conditions, the total economic impact for
all cases was considered in the analyses as illustrated inTable 3.
However, this study has some limitations of developed traffic simulation program, as it can not simulate
the internal trips and the effects of junction delays. Therefore, when the internal trips in the developed zones wereincreased, because of higher attractiveness, it would reduce the number of trips going out from the zone. Thismight make the traffic conditions in that zone seemingly
less congested than before, but not actually. If the effects
of internal trips and the intersection delays can be considered, more realistic impacts can be presented. These
require improving the performance of the simulation program in order to cover the capabilities of micro simulations for further research.
4.6

The single development case
Based on the total zonal economic impact, it was
found out that in the single development case, Zone 179
was the most suitable area for the proposed shopping cenIATSS RESEARCH Vol.28 No.2, 2004 •63

TRANSPORTATION

171
168

167

171

172

167

168

173

Very Low Impact
Low Impact
Medium Impact
High Impact
Very High Impact

169

174

170
177

173

175

169

179

178

170
177

180

176

172

167

168

173
169
170

172

167

169
170
177

178

180

(c) Case No. 4

174

169

179

178

170
177

170

175
174
179

177

180

(d) Case No. 5

178(e) Case No. 6

171

172

167

168

173
169

172

176

171

168

172
173

175
174
178

169
179

170
177

180

175
174
178

179
180

176

176

(f) Case No. 7(g) Case No. 8

Fig. 10 The negative economic impact distribution of each development case64 • IATSS RESEARCH Vol.28 No.2, 2004

180

173

176

176

167

168

175

179
177

178

171

173

175
174

179

(b) Case No. 3

171

171
168

175
174

176
(a) Case No. 2

167

172

180

ZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDA

Table 3 The comparison of total economic impact for all development cases
TypeSingle Development

Simultaneous Developments

Group

Development Case

Rank

Total Zonal Economic Impacts

Case No.2

2375,651

Case No.3

3394,187

Case No.4

1-92,966

Case No.5

1-3,370Case No.6

3348,072

Case No.7

2308,178

Case No.8

4385,675

One Project

Two Projects
Three Projects

Unit: Baht per Hourter project, due to its location advantages. Zone 179 is
located in the center of the radial network in Bangkapi,
there are many main roads approaching this zone. However, the additional travel cost impacts caused by the
project was imposed into Zone 169, 170, 178, and 179,
respectively as illustrated in Figure 10 (c). This might bebecause these zones have good networks connected toZone 179, so travelers want to pass through them. Especially for Zone 170, because of the located expressway,
many travelers pass through the zone with a very high impact. For Zone 168 and 173, they were the second and third,
respectively. Zone 168 was more suitable than Zone 173,
as it has a better transportation system, the RamintraAtnarong expressway. It was noticed that most trips to Zone
168 produced from Zone 167, 170, 176, 178, and 179, andalso in these zones there were networks to access Zone 168
easily, hence a lot of economic impacts generated along
these areas as demonstrated in Figure 10 (a).
4.7

The simultaneous development caseAs shown in Table 2, if there were two of the same
project implemented in two zones at the same time or ina certain period, the best case was the implementation ofprojects in Zones 168 and 173 as shown by reduced travel
cost impacts, -3,370 Baht/hour. It might be because thecase of development projects in Zone 168 and 173 could
attract some trips that concentrated in the areas of Zone
176 and 178, very crowded commercial areas along
Ramkamhang road, to their areas. Many trips that travel
through Zone 170, 176, and 178, could go directly to the
new activity areas, eventually it facilitated to efficiently
rearrange traffic distribution in the network. The developments in Zone 173 and 179 were the second suitable
alternative. They generated higher negative impacts thanin the case of Zone 168 and 173, this might be because
Zone 173 and 179 are in the central areas that are very
crowded and congested, especially along Ladproa andRamkamhang roads. The performances of networks

around Bangkapi Business Center could not handle theaccess demands of projects, so more congestion was
spread out along the two main roads. As demonstrated
in Figure 10 (f), Ladprao road in Zone 175 andRamkamhang road in Zone 178 were significantly affected from the land development projects. In addition,
the expressway in Zone 168 connecting between Ladprao
and Ramkamhang roads were also more congested, due
to the new developments in Zone 173 and 179. Finally,
there was no doubt that the case of development in all
three zones had the most severe impact as illustrated in
Figure 10 (g). From the assessments, it was very obvious that the capabilities of the transportation system inthe developed zones should be evaluated to control or balance between the travel demands of any activity area andtheir own network capabilities.
From the results of impact assessments, it was
found that the locations of zones can influence the performances of areas serving land developments. The areas located near the high capacity networks have the fullcapabilities to handle the access demands of forthcoming activity centers, and the impacts generated in suchzones will be insignificant. This point is realized by planners in Bangkapi, and they planed to implement Zone 179
as the business center. The zone is in the center of radial
networks connected by five main roads, so the complete
network performances are sufficiently provided. However, in approving simultaneous developments, planners
must improve the performance of infrastructure in
Bangkapi to catch up with the demands of multi-projects.
They can continue to promote Zone 179 as the center, butother projects in other zones have to be seriously prohibited as the comprehensive plan. Otherwise, those developments will create a lot of adverse impacts for society.
Without any network improvements in Zone 179, two
shopping center projects should be implemented in Zone
168 and 173, as the better transportation services can beprovided by the high capacities of the expressway in Zone
IATSS RESEARCH Vol.28 No.2, 2004 •65

TRANSPORTATION

66 • IATSS RESEARCH Vol.28 No.2, 2004

required to assure continued fit. Under the conditions ofrapid urbanization in developing cities, the ZIA framework can quickly and continuously be re-assessed andmodified as the situation evolves. Finally, the ZIA
framework is a process. It is continuous and recognizes
the need to be open to changing goals and activities inlight of shifting circumstances within the urban growth
conditions. It is a process that requires monitoring andreview mechanisms capable of feeding information toplanners continuously. The strategic planning approachis not something that can be applied only once and forgotten or ignored. The planners can apply the ZIA
framework to assess the land development impact ontransportation networks, and try to control proposed landdevelopments together with the enhancement of network
performances in the focused areas every 5 years the sameas the planning horizon of the National Economic and Social Development Plan and the National Transportation
Plan as illustrated in Figure 11. It attempts to minimize
the undesired consequences of urbanization in some zones
or for the whole study area. The growth in developing
cities is very rapid, so direct long term planning may not
be suitable, due to a lot of uncertainties. The proposed
framework can be expected to investigate the influencesof land-use developments, and supports planners to mitigate adverse impacts. Although it may not be able toreach the planned target in the short term, it can provide
the direction to manage the growth and gradually implement some control or mitigation measures for any activity areas in the comprehensive land-use plan. Eventually,
it will create the balances of land developments and infrastructure provisions with good living environments forthe cities.

5. CONCLUDING REMARKSThis paper intends to present the Zonal Impact

Unplanned
Growths

Indicator Level

168. The ZIA framework can evidently demonstrate thezonal impact distributions to show which zone will be significantly affected from any land usage. It was found thatthe zone occupying the better networks will play the roleas the main impact distributor to allocate or mitigate theimpact. As shown in Zone 170, it is the zone mostly influenced by traffic impact of the proposed project(s). In
addition, after implementing any projects, the overcrowded zones around a developed area are more significantly affected than the less congested zones. This wasindicated in Zone 178 often imposed by severe development impacts for analysis cases. Planners should pay
more attention to these zones.
The existing approach of planners in BMR cannot
cope with the complex development situation, especiallywhen more than one project is implemented over the cityarea. Only the considerations of existing physical conditions
consisting of land-use and networks in the present land-use
planning process are insufficient, so the ZIA framework was
proposed to improve the planning ability. The ZIA framework is beneficial to enhance the powers of regulations andplans for land-use planning. By conducting various simulations, the influences of project size can be covered in theplanning process. Therefore, the suitable limitations of development sizes for each area can be determined and referred to as the rules or standards in the land-use control
plan. The transportation improvement plans can be determined so that they are compatible with the planned landdevelopments or not. If the plans fit with the directions ofurban expansion, the traffic impact of developments should
be minimized and mitigated efficiently.
It can be noticed that the ZIA framework consistsof four characteristics of a strategic planning approach12.
First, it is oriented toward the future. It recognizes thatthe land-use conditions will change in the future. It is along range orientation, one that tries to anticipate events
rather than simply react as they occur. It is recognizedthat future land developments are difficult to be controlled, but argues that by anticipating future developments, the plans can help to shape and minimize theunfavorable impacts of urban developments. Second, thestrategic approach has an external emphasis. Many external components are concerned, such as the political influences on national and regional development plans,various secondary development impacts like pollution andtravel cost impacts. In fact, it can be extended to coverother external matters such as political and social dimensions etc. Third, the strategic approach concentrates on
assuring a good fit between the real land-use conditions
and planned ones and attempts to anticipate what will bePlanned Growths
Existing
Level

Adverse Impact
Decrease

Milestone

Historical
Data

Planning Horizon
Present

5th Year

10th Year

Fig. 11 The multi planning stages of ZIA framework instrategic planning approachZONAL IMPACT ANALYSIS OF A STRATEGIC PLANNING APPROACH FOR LAND DEVELOPMENT CONTROLS

Analysis (ZIA) framework to improve comprehensive
land-use planning for balancing land developments andtransportation performance in developing cities. The landuse planning process in Bangkok and its problems weremainly explained as a case study. Although, theBangkokian planners have tried to apply the traffic impact assessment (TIA) to mitigate the impact of development projects, it is insufficient to effectively control
the urban growth, as the TIA focuses on the specific site
level only. In particular, the situation worsens, when theland-use planning process does not seriously concern theeffects of land developments on the networks. It waspointed out that what the planners need is the tool to systematically establish the effective comprehensive land-use
plan in controlling land developments of each area to becompatible with their transportation performances.
The ZIA framework was defined as a tool for a
strategic planning approach. Under the framework, theimpacts generated by the developments were evaluatedbased on the zone base model. To demonstrate the framework application, it was applied to the Bangkapi District,
Bangkok. It was found that the zonal impact assessments
help to find an optimum development alternative to cooperate between transportation planning and land-use
planning that mainly a uses zoning system in land-use
control. The zonal impact distributions were also obviously demonstrated so that planners can prepare some
impact relieving measures in advance, especially in thesignificantly affected zones.
In the results of a ZIA case study, more comprehensive development alternatives were established andtheir zonal impacts could be evaluated. It was recommended that the most suitable zone for a single project
is Zone 179. Because the zone is located in the center ofa radial network, full accessibility can be provided toserve the forthcoming project. However, in simultaneousdevelopments, if none of any network improvements in
Zone 179, two projects should be implemented in Zone
168 and 173, as the high network capacities of the expressway are available. In addition, Zone 170 and 178
would be significantly imposed by the severe development impacts, so planners should pay more attention to
mitigate in these zones. Especially for Zone 170, becauseof its high quality of transportation services, it attracts
more additional trips to the zone as bypass trips together
with a more congested situation. These results indicate
the better understanding on the characteristics of land-use
and transportation integration planning in Bangkapi than in
the traditional process. Finally, it was emphasized that the
ZIA framework is a useful tool for strategic urban planning

K. LIMAPORNWANITCH, K. TEKNOMO, K. HOKAO, A. FUKUDA

in developing counties. It should be realized that based on
the existing transportation and land use database system, theeffects of internal trips and intersection delays in each zone
are not taken into account to consider the zonal impact assessment. To evaluate real zonal impact, we need to develop
more complete databases and simulation programs. However, this might be difficult to implement for planning processes, especially in developing countries, because there areseveral limitations of technical knowledge, as well as budgetary restrictions.

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ACKNOWLEDGEMENTS
The authors are grateful to the Office of the Transport andTraffic Policy and Planning (OTP) and Division of City Planning(DCP), Bangkok Metropolitan Administration for their contributionsin providing valuable data. This study is part of the dissertation fora doctoral degree in Saga University under the financial support by
the Japanese Ministry of Education, Science and Culture.
IATSS RESEARCH Vol.28 No.2, 2004 •67