Urban Regeneration and Sustainable Urban Development from Polycentric Spatial Structure Traffic Performance

Traffic congestion and air pollution have become the main phenomenon of agglomeration dis-economy in urban. As one of the means to alleviate the agglomeration dis-economy, the traffic performance of polycentric space structure needs to be further tested. The study examines the traffic performance of polycentric spatial structure in Harbin, China. Discusses the relationship between regeneration and traffic efficiency of polycentric spatial structure. The study was divided into three parts. The first part, the study adopted the social survey method to collect the information of working and residential location, commuting mode and time, subjective commuting feeling and influencing factors of employment and residential location selection with employees in urban centers as the objects of investigation. The second part is traffic performance test of polycentric spatial structure, a positive polycentric space structure should have three aspects of traffic performance. First, shortening the commuting distance, reducing excessive commuting, reduce road pressure, traffic congestion and air pollution, when the ratio of the average commuting distance between centers and the city is less than 1, the polycentric space structure is beneficial to shorten the commuting distance. Second, shortening the commute time and reducing the time cost, when the ratio of the average commuting time between centers and the city is less than 1, the polycentric space structure is beneficial to shorten the commuting time. Third, increase the proportion of green transportation. The traffic performance of polycentric spatial structure is evaluated through the above three points. The third part is to analyze the influencing factors of traffic performance combining with the co-location hypothesis. The spatial separation of employment and residence is the core reason that affects the traffic performance of polycentric spatial structure, the co-location hypothesis holds that households and enterprises adjust their positions periodically to achieve the residence-employment balance and shorten the commuting distance, The core of the co-location hypothesis is the re-balancing of the commuting cost with the location benefits of employment and residence. When the cost of commuting is greater than the benefit of the current employment and residential location, location re-selection occurs. Residents can reduce the commuting distance and time by changing their work and residence. It is most important that commuting cost has enough weight in location selection to compete with location benefits of residence and employment. The factors that make long-distance commuting affordable are the focus of urban regeneration and sustainable urban development. The commuting distance is not determined by the cost of commuting alone, but by the comprehensive cost-benefit. The case study of Harbin shows that the average commuting distance in centers is greater than that of the city, and the proportion of long-distance commuting is higher, but the faster commuting speed in the fringe area makes average commuting time shorter than that of the city. The importance of commuting costs is insufficient, the employment and residential location resources are extremely unbalanced, and they influence the process of location re-selection and makes long-distance commuting economically reasonable. The fundamental ways to improve the traffic performance of polycentric spatial structure are to face up to the rationality of long-distance commuting and traffic demand, adjust commuting cost and the balance of residential and employment location resources, improve the relationship between occupation and housing.