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Karin Limapornwanitch, PhD (Doctor, Civil Engineering), Saga University, September 2004. Thesis title: Evaluation of urban land development and induced traffic using the integrated zonal impact analysis

Abstract:

Many efforts of urban and transportation planner have tried to integrate land use and transportation planning for years. Those efforts could be grouped into two approaches, developments of analysis tools and planning frameworks. Due to the complicated relationships of land use and transportation, and limitations of data availabilities, budget, and human resources, the development of advanced analysis tools are difficult to be implemented in poorly planned cities. Therefore, the planners in these cities have employed the planning concepts to integrate land use and transportation plans. Through planning concepts, many impact assessment frameworks have been developed and utilized as the tools to balance land developments and transportation capabilities. However, because of different analysis levels, the existing impact assessment frameworks are suitable for micro and macro planning levels only. While land use planning utilizes the zoning system to control land developments in the Mezzo-Scale, there is no any impact assessment framework to deal with the consequences of urban growths at this level. This makes the integration of transportation and land use planning becomes difficult. To fulfill this gap of knowledge, this dissertation have proposed an alternative of impact assessment approach, Integrated Zonal Impact Analysis (IZIA) framework, to improve managing urban developments, especially for poorly planned urban areas. In addition, another two interesting points were also explored through the findings of study. They include an alternative of impact integration, and the enhancement of stakeholders’ roles in land use and transportation planning.

The proposed IZIA framework consists of four main parts, consisting of the land use planning data preparation, transportation planning data preparation, zonal development impact assessment, and the participation of community in integrated impact assessment. Under this framework, the impacts are assessed and analyzed into the zonal level so that the development impacts caused any land use project can be obviously distributed into each zone. This study applied the proposed IZIA framework into Bangkapi District, Bangkok, as a case study. The shopping center project(s) was considered for the land development projects. Based on land development potentials in Bangkapi, there were three zones considered for implementing the forthcoming project. They include Zone 168, 173 and 179. To simulate the traffic impacts, the new transportation database system was prepared into the zone-base, and eight development alternatives were created by including single and simultaneous developments, and the base case without any development project. Based on the comparisons of normalized traffic impacts among single development alternatives, it was found that the implementation of project in Zone 179, was the best alternative, because of lowest total impact index. In simultaneous alternatives, the best alternative was the case of two projects in Zone 168 and 173. The zonal impact distribution of both best alternatives pointed out Zone 170 was significantly affected by the traffic impacts of projects. The traffic impacts were considered into the further secondary impact assessments, including economic and environmental impacts. Both kinds of zonal impact assessment gave the same suitable alternatives. This might be because these secondary impacts were estimated based on traffic impact indicators, so their secondary impacts were similar to the traffic impacts. However, according to assessments of economic and environmental impacts, it was very evident that pollution impact costs were very huge social costs.

The dissertation also tried to investigate the public preferences on development impacts. There were three stakeholder groups, including residents, commuters, and visitors. Their preferences and opinions were collected through questionnaire and interview surveys. Totally, there were 1,064 questionnaires collected, but after the data verification, only 972 samples could be used as the final samples or about 91.35 % of obtained total samples. The statistical and multivariate analysis methods, including independence tests with 2-Tests and Cluster Analyses, and Analytic Hierarchy Process (AHP) were employed. It was found that the public gave more value sense on the environmental issues than transportation issues. This informs that most people really want to improve the environmental conditions in the study area. The priorities of economic and environmental impacts were 0.36 and 0.64, respectively. These weights were necessary to be considered as the interrelationships between impacts in the viewpoints of social values, and they were utilized into the impact integration process. The average values of acceptable development impact levels were determined to estimate the willingness of communities for accepting such impacts. The average of acceptable travel cost for whole study areas and all stakeholder groups was 24.69 Baht/trip. The average of acceptable travel time for whole study areas was 23.35 min/trip. The useful information of community perception was provided so that an effective impact mitigation plan can be developed.
In the integrated appraisals, the dissertation has proposed an integrating way based on the interrelationship between economic and environmental impacts in the community’s viewpoints. As the results, the communities in Bangkapi gave more importance on pollution impacts rather than economic impacts, about 1.78 times. This value was called “Comparative Impact Weight”, and utilized into the integration of impacts. Based on this social value, willingness to accept integrated impacts could be estimated in order to calculate Index of Acceptance of Development Impact (IADI) for identifying the sensitive area. It was found that in single developments, Zone 170 was the sensitive area, as shown by its IADI higher than 1.00. In simultaneous developments, although there was no sensitive area, but Zone 176 and 170 occupied the highest indices compared to other zones. Particularly in Zone 170, it was emphasized that this zone was imposed by severe impacts of development project in any zone of Bangkapi. This is unfair for the people living in that zone. Therefore, planners should pay attention to mitigate the negative consequences in these areas.

In addition, the influencing factors of zonal conditions towards zonal development impacts were also investigated. The results presented that the condition of networks in each zone mainly influence on the development impacts distributed into each zone. However, the relationships were in the positive directions. This finding implies that more roads may increase more trips in the zones, so the management approaches, including transportation system and travel demand management, are necessary. Base on the public perceptions surveyed, planners in Bangkapi are recommended to provide the plans into two levels, consisting of overall and specific area levels. In the overall area level, the plans should be based on the existing conditions of land uses in each zone. As shown in the analyses, the conditions of zones can effect to the public preferences, due to their experiences in the areas. For the specific area level, it should be considered based on the stakeholders’ characteristics in each zone, including socio-economic conditions, travel behaviors, and life styles. The main goals of impact mitigation plans should be to conserve or increase the qualities of living environments.

Finally, it can be concluded that the IZIA framework is a strategic planning process to effectively control the future urban developments into the direction of livable cities.