中文摘要：

正确理解可变情报板（VMS）诱导信息影响下的驾驶员路径选择行为，是高效发挥VMS作用的必然要求。采用SP调查（意向调查）探索VMS同时提供快速路和替换路径行程时间条件下的路径选择行为，采用离散选择分析方法对影响路径选择的因素进行了多变量分析，建立了描述路径选择概率的二元probit模型。Probit模型中的行程时间节省量这一解释变量的系数视为服从对数正态分布的随机系数，以反映行程时问重要性在人群中的不纯一性（heterogeneity）。分析表明，驾驶员的路径选择会受VMS诱导信息显著影响，VMS影响大小取决于VMS信息内容、驾驶员个体属性（年龄、驾龄、用车类型以及快速路使用频率）、以及替换路径属性（所含信控交叉口数目）。具体地，（a）VMS所告知的行程时间节省量越大，改道可能性越大；（b）年轻和年长者较之中等年龄者，改道可能性更大；驾龄越长，改道可能性越大；非单位公车驾驶员改道可能性更大；使用快速路频率越低，改道可能性越大；（c）替换路径所含信控交叉口越多，改道可能性越小。研究成果可为更好地设计、运行和评价VMS信息发布策略提供参考。

英文摘要：

For better supporting informed diversion decisions in case of congestion and incidents, it is important to provide drivers with detailed real-time traffic information such as travel times on intended and alternated routes through Variable Message Signs （VMS）. This paper used a stated preference （SP） approach to undertake a quantitative assessment of the potential effects of travel time information provided by VMS on en-route diversion behavior of Shanghai urban freeway drivers. Using SP data, a binary probit model was estimated with a log-normal random coefficient accommodating heterogeneous taste preference for travel time savings. The main findings follow. Drivers＇ en-route decision on diverting from the regular freeway route to the alternate local street route can be significantly influenced by VMS information. The impact of information is significantly influenced by the characteristics of driver, route, and VMS message of travel time. Travel time saving and drivers＇ driving age serve as positive factors in drivers＇ diversion behavior. Signal number on alternate local route, driving employer-provided public car, frequency of driving on freeway, and driver＇s being mid-age, serve as negative factors in diversion behavior. The findings have important implications for the operation of VMS-based advanced traveler information systems （ATIS）.