SP Approach toward Driver Comprehension of Message Formats on VMS

This study attempts to examine driver comprehension of the traffic information that is presented in three formats, namely, the numerical format, the description format, and the switch-on-light format. A stated preference survey with well designed attributes regarding travel conditions and comprising a total of 475 successful cases for Hong Kong drivers has been conducted for this purpose. Binary logit models with respect to drivers' traveling preference of two designated routes under different traffic conditions were developed and found to have considerably high goodness-of-fit statistical values. The final models were specified with 11 variables. The explanatory variables employed in the models include those referring to respondents' socioeconomic background and those characterizing the transport network. Based on the findings, it is possible to conclude that drivers have different comprehension of the formats for presenting traffic information on variable message signs, and the message formats can induce biases toward a route in drivers' decision-making processes.