Transportation Demand Management Policy Evaluation Based On Disaggregated Model

Urban traffic congestion is a problem the world now facing. The origin of it is the unbalance between the traffic supply and demand. Long periods of transportation management practices have proved that, in order to solve the traffic congestion problem, increasing financial support and accelerating transportation infrastructure construction is not enough. Especially in large cities of our country, the basic road network has coming into being and the land resources can be used is becoming more and more limited. With the economic development and accelerating urbanization, residents in rural areas are swarming into the cities, travel demands are increasing quickly, and new roads are walled up quickly because of the increasing vehicles. Therefore, although the level of traffic supply is advanced increasingly, the traffic congestion problems are becoming more and more serious. In recent years, transportation planning and constructing departments began to realize that in order to solve the traffic congestion problem, when increasing the traffic supply, some effective transportation demand management strategies have to be adopted to control the traffic demand increasing and to adjust the demand structure. This will be an efficient method to promote the balance of the traffic supply and demand, and to solve the traffic congestion problem. TDM policy aims to reduce traffic volumes and travel time-space consumption, build up a healthy traffic system, and improve urban environment, by controlling traffic demand increasing and adjusting the demand structure using management policies, law and advanced information systems. The core of it is to solve traffic congestion problem by rationalizing people's travel modes. However, practices have proved that not all the TDM policies can achieve the anticipated effect, some are not accepted by the travelers, some can mislead the travelers, and some can even baffle the urban development. Therefore, in order to implement the TDM policy correctly, it is necessary to forecast the effect of TDM strategies on transportation, economy, and environment system, assess the feasibility of the projects, and improve the implementing program, by analyzing residents'policy responding behaviors and simulating the traffic flow.Based on these backgrounds and combined with the National Natural Science Foundation of China (NSFC), the activity-based travel behavior analysis model and TDM policy simulation evaluation method (50578094) and the Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP), the activity-based disaggregated travel choice model (20030183008), this paper attempts to develop a systemic TDM feasibility analyzing pattern, evaluation method and model system which has comprehensive applicability, based on analysis of the traffic condition, the social and economic environment, and residents'standard of living in our country. Then evaluate the TDM policies in representative area using the assessing model system, in order to drive the research and application of TDM in our country, and improve the healthy and sustainable development of urban transportation system. The main contents of this paper can be summarized as follows: 1. Disaggregated model theory, data survey method and aggregating method In this section, basic modeling theory, estimating and testing method of model was discussed. The modeling method and model structure of some major models, such as logit, are introduced. An RP/SP data survey program was developed. Then the aggregating method of disaggregated models was studied.2. TDM policy evaluation method, indexes system and evaluation model systemThe basic theory and implementing cases of TDM policy was summarized and assessing indexes system of TDM was developed. By comparing several TDM evaluation methods, combining disaggregated models, activity-based travel demand forecasting method and"four-step"model, a TDM evaluation model system was developed. Then the modeling theory and applying method of the sub models was introduced.3. The evaluation model system of traffic structure optimizing policyIn this section, the implementing method and cases of traffic structure optimizing policy were introduced. Using disaggregated model, including MNL and NL model, the traffic structure optimizing policy evaluation model system was developed, and sub models were estimated with SPSS and STATA software. The calculation method of value of time was studied as well.4. Case study—evaluation of traffic structure optimizing project in NanhaiIn this section, traffic structure optimizing project for Nanhai was constituted based on supply-demand condition analyzing of Nanhai transportation system. Using traffic structure optimizing policy evaluation model system, the implementing effects of the project was predicted and feasibility of it was evaluated in aspects of policy acceptability, adjustment of residents'travel behaviors and change of road saturation. According to the evaluation results, an optimized project was advanced.The main innovations of this paper are:1. A systemic TDM feasibility analyzing pattern, evaluation method and model system which has comprehensive applicability was developed.2. Combining policy acceptability analysis, residents'policy responding behaviors forecast and traffic flow simulation, a traffic structure optimizing policy evaluation model system was developed and used to constitute and evaluate TDM policy in representative area.3. A new calculation method of value of time was advanced based on product method, earning method and Probit model, which optimized the traditional calculation methods. 4. An integrated aggregating method of disaggregated model was advanced, which is fit for TDM evaluating and RP/SP survey data.