考虑行程时间不确定性的服务设施时空可达性度量

在我国拥挤的多模式交通网络中，出行者的行程时间具有较大的不确定性.行程时间不确定性是影响人们出行行为选择的重要因素，对于某些重要活动(如就医等)，人们对行程时间的可靠度有较高要求.本文以南京市玄武区综合医院的时空可达性为例，采用引力模型和行程时间预算模型深入探索多模式交通网络中服务设施的时空可达性，提出了考虑行程时间不确定性的时空可达性度量方法，针对不同交通模式分析了出行者的风险规避行为，为城市多模式交通规划和土地利用布局提供了有效依据及评价指标.研究表明，对于不同的交通模式，在不同可靠性下服务设施的时空可达性具有显著差异.

Measurement of Space-time Accessibility to Service Facilities Considering Travel Time Uncertainty

In congested multi-modal transport network in China, the uncertainty of individuals’travel time is significant. The travel time uncertainty significantly affects individuals’travel choice behavior. To conduct some important activities such as seeking medical service, individuals normally have high expectations of travel time reliability. This paper takes the space-time accessibility of general hospitals in Xuanwu District of Nanjing as an example. The space- time accessibility of service facilities in multi- modal transport networks is intensively explored by extending the gravity model and the travel time budget model. A new method is proposed for measuring the space- time accessibility with consideration of travel time uncertainty. Individuals’risk decisionmaking behavior is analyzed regarding different transport modes. The results provide effective bases and evaluation indicators for urban multi-modal transport development and land use planning. The results show that using different transport modes, there are significant differences among the space-time accessibilities to service facilities under various travel time reliability constraints.