Abstract: Indifference threshold is one of the important influencing factors in traffic demand forecasting. In view of the uncertainty of traveler’s path travel time and vehicle parking time, the travel mode selection model based on indifference threshold under uncertainty conditions was established, which took the travel time budget (TTB) as the selection standard of travel time for travelers. Moreover, the scenario of multiple users was also considered, and the influence of uncertainty on traveler’s choice behavior was analyzed. The research results show that when the indifference threshold is fixed, as the expected punctual arrival probability increases, more travelers will choose the way with high travel time reliability. When the indifference threshold is considered, the expected punctual arrival probability has less influence on the behavior of mode selection, and the greater the indifference threshold is, the smaller the influence is. In the case of multiple users, travelers who expect a higher probability of punctual arrival will have a larger travel time budget and are more likely to choose a more reliable way to travel.

Key words: traffic engineering; indifference threshold; travel time budget; reliability; stochastic user equilibrium

摘要： 无差异阈值是交通需求预测中重要的影响因素之一。针对出行者路径走行时间和车辆寻泊时间的不确定性，以出行时间预算(TTB)作为出行者时间的选择标准，建立了不确定条件下基于无差异阈值的出行方式选择模型；基于多类用户的情景，分析了不确定性对出行者选择行为的影响。研究结果表明：当无差异阈值一定时，随着期望准时到达概率增加，更多的出行者会选择出行时间可靠性高的方式出行；在考虑无差异阈值条件下，期望准时到达概率对方式选择行为影响变小，且无差异阈值越大其影响越小；在多类用户情形下，期望准时到达概率越大的出行者出行时间预算越大，更倾向于选择可靠性高的方式出行。

关键词: 交通工程；无差异阈值；出行时间预算；可靠性；随机用户均衡