Contribution of Travel-Related Variables to Car Commuter's Mode Change

Traffic congestion as a source of daily delays, degradation of environmental quality, and nonrenewable energy consumption is said to be a major trouble in most of the world’s cities. Being discontent about traffic congestion usually persuades transportation policymakers to propose measures to reduce it. Many studies have shown that individuals’ responses to urban traffic congestion, as usually assumed by policymakers, are significantly different from their respected actual behavior. This paper adopts a behavioral approach to examine the role of travel-related variables on the mentioned difference using design of experiments principles and logit models. In this approach, five policies namely cordon pricing, parking pricing, increasing fuel cost, transit time reduction, and transit access time reduction were investigated. This study uses the stated preferences of individuals who regularly use their private cars to access their job locations in the Tehran central area to calibrate seven models of non-car mode consideration. Furthermore, the role of travel-related variables is also addressed in such mode change. Analysis of the effects of the travel related variables in considering non-car modes shows that the contribution of socio-economic variables are greater than travel-related variables in all of the investigated modes. The results show that while the contribution of travel-related variables is 43% for walk and ride considerers and 31% for taxi considerers, it is 12% for considering motorcycle, 10% for public transit accessed by either car or taxis, 5% for taxi caught by phone and 1% for taxi accessed by car.