基于TVP-VAR模型的多模式交通需求耦合分析

城市交通出行选择多模式条件下多种出行方式之间的出行需求关系密切，为了探讨城市居民对地铁、公交车、私家车3种出行方式出行需求之间的耦合关系及时变特征，采用时变参数向量自回归（TVP-VAR）模型，使用道路拥堵指数近似代表私家车出行量，对2个小区一个月内工作日时间地铁出行量、公交车出行量和道路拥堵指数三者的平均值进行分析。研究结果表明：地铁出行量、公交车出行量、私家车出行量三者相互作用关系针对不同的用地类型，整体影响趋势不会变化太大，影响大小在时间上存在差异；城市交通小区内居民对地铁、公交车、私家车3种出行方式的出行需求之间全天存在相互作用关系，地铁出行需求的增加会减少公交车出行需求，公交车出行需求的增加会增加地铁出行需求，而私家车出行需求的增加会增加地铁出行需求并减少公交车出行需求。研究结果有助于深入认识现阶段中国城市多模式交通出行方式之间的耦合关系，以更好地应对城市交通拥堵问题。

A coupling analys si of multi modal transportation demands based on TVP-VAR models

Under the condition of multimodal travel choices in large cities , there is a close relationship of traffic demands among subway, buses and private cars.In order to explore the coupling relationship and time -varying feature among multimodal traffic demands, with road congestion index representing the traffic demands of private cars, this paper adopts the time-varying parameter vector autoregressive (TVP-VAR) model to ana-lyze one-month travel demands of subway, buses and road congestion index on weekdays.The empirical re-sults of two traffic zones demonstrate that:Depending on different land use types, the relationship among sub-way demand, bus demand and private car demand does not significantly change in trend, but varies in time scale;In urban traffic zones, there is an interactive relationship among traffic demands of subway, buses and private cars.As subway demand increases, less passengers will switch to buses.When bus demand increases, subway demand will increase correspondingly.The increase of private car travel demand will increase the sub-way travel demand but reduce the bus travel demand.The research is helpful to understand the coupling rela-tionship among different travel modes in our country at the present stage, and thus to better cope with the issue of urban traffic congestion.