Studies On Transportation Planning Theory Based On Accessibility

The urbanization and motorization process has been accelerating with the development of society and economy during the decades of Reform and Opening up policy. The traditional mobility-oriented planning thought is unable to solve the more severe transportation problems than ever before and cannot meet the increasing personal travel demand for high efficiency and high accessibility. Therefore, it is of great significance to make changes to traditional transportation planning thought, theory and methodology. After the analysis on the major problems in China urban transportation system during the past thirty years, it is suggested that shifting from mobility to accessibility is a good way to handle the current situation and meet future trends.The accessibility-oriented planning theory and methodology is proposed based on the concept of accessibility and the interaction between transportation and land use. The original thinking and comprehensive solutions include reshaping urban land use patterns, analyzing travel demand characteristics and optimizing transportation networks, using theoretical and practical tools and optimization algorithms.Firstly, comparative study is conducted to examine the existing accessibility models from both the theoretical and practical aspects. Then the relationship between accessibility and mobility is discussed. The inverse relationship found in the discussion is an urge to shift from mobility-oriented to accessibility-oriented planning and helpful to establishment of the planning theory and methodology based on transportation accessibility.At the macroscopic level, the feedback mechanism and the role of accessibility within the interaction between transportation and land use is analyzed. Based on the quantitative relationship between land use and transportation, a new accessibility model based on individual travel utility is derived. In order to integrate transportation into land use planning process, we introduce the concept of job-housing balance and construct a bilevel programming model, considering the optimal allocation of land use within floating analysis areas, equity of the spatial distribution of accessibility and feedbacks between travel behavior and land use. At the microscopic level, aiming to simulate the multi-objective decision process of network design problem, a multi-objective bilevel programming model combined with personal travel choice is proposed. The tradeoffs between the objectives are reflected by Pareto optimal solutions.This paper takes Dalian as an example to explain how to apply these models in practical issues. Finally, the future research directions are summarized.