Models For Public Transit Infrastructure Investment Decisions And Vehicle Emission Tax Evaluation

With the acceleration of urbanization and the rapid growth of national economy,the number of urban motor vehicles has risen sharply,which has brought a series of urban problems and become an important factor restricting the healthy and sustainable development of cities.For example,the disorderly and excessive urban sprawl makes people's travel cost more and more expensive.The increasing contradiction between traffic supply and demand makes urban traffic more and more crowded.The deteriorating urban environment seriously threatens people's health.Based on this,experts and scholars advocate transit-oriented development(TOD).On the one hand,increasing investment in transport infrastructure,such as many cities in China are planning to invest heavily in subway construction and improve urban traffic supply;on the other hand,building TOD community which integrates residential,commercial and social services,fundamentally reduces travel demand and provides convenience for public transport travel.At the same time,appropriate transport policies are introduced to optimize the spatial distribution of urban residents,so that the distribution of urban traffic demand is more reasonable.In view of this,this paper discusses the investment of rail transit network,the design and optimization of TOD zones along a rail line,and the impact of vehicle emission taxes policy on the distribution of urban residents.It provides theoretical support and scientific basis for the relevant government departments to formulate policies.Firstly,this paper discusses the multi-stage investment of interrelated projects in the urban rail transit network.Compared to the general road network design,the investment of urban rail transit network is more complex due to greater capital cost and longer time span required.Based on the traditional road network design model,this study firstly considers the time dimension of urban rail transit network investment and the relationship among rail transit projects.The proposed model determines when to select and complete projects in the urban rail transit network(i.e.project selection,investment sequence and completion time).At the same time,it optimizes the evolving train headways of rail lines with the development of the rail transit network,in order to minimize the total discount cost of the rail transit system during the planning period.Secondly,this paper studies the TOD investment issue along a rail line corridor.This study proposes an urban system equilibrium model with TOD investment for the first time.It considers the impact of TOD investment on residential choice behavior,housing market supply and demand balance and land value.This paper discusses the investment of TOD zones,including the location,number and size of each TOD zone.At the same time,the paper also considers different investment schemes,namely,public investment scheme and private investment scheme.In public investment regime,the government is responsible for the investment cost of TOD projects,which is borne by the private property developers in the private regime model.Finally,this paper explores the impact of vehicle emission tax on the distribution of urban residents with different income levels.With the consideration of residential segregation phenomenon,this paper proposes a city equilibrium model considering heterogenous households with different income levels.The proposed model includes three types of agents: government,property developers and households with different income levels.The analytical properties of the model are discussed,and the optimal level of vehicle emission tax under the maximization of social welfare is determined.At the same time,the analytic conditions of the distribution pattern of the rich living in the city center while the poor living in the suburbs or the poor living in the city center and the rich living in the suburbs are given.