Analysis on Car Commuters' Behavior During a Massive Downpour Based on Probe Data and Questionnaire Survey

Abstract

A massive downpour due to Typhoon Roke attacked the Tokai region on 20th September, 2011. Several roads in the northeastern part of Nagoya city and the adjacent areas were closed to traffic, resulting in a serious commuter chaos. In this research, we attempted to explore the effects of departure hours, early or late departure, the significance of acquiring proper traffic information as well as the impacts of road closures on the level of difficulty of home returning trips. Regression models were developed using both questionnaire survey and taxi probe data. Questionnaire survey can gather drivers' information; however, it is difficult to gather the actual changes in travel condition. On the other hand, probe data can demonstrate a real time change in travel condition at every couple of minutes. Therefore, this study presents a combined usage of both data for a clearer explanation on the travel condition and the behavior of drivers during the typhoon. The findings revealed that the difficulty to gather reliable and comprehensive information on the traffic regulations enforced temporarily during the typhoon had led drivers facing the closure sections and the consequent very long travel delay. In fact, these delays can be avoided if the drivers had chosen the right detour route from the beginning. Based on the findings, this paper also suggests some proper countermeasures to reduce the severity of commuter chaos for the future disaster.