EVALUATION OF CAUSAL FACTORS AFFECTING DRIVERS’ READING TIME ON VARIABLE MESSAGE SIGNS

摘要

Variable message sign which is used for providing real-time information on traffic conditions and accidentoccurrences is an important component of intelligent transport systems (ITS). Proper consideration ofdrivers’ message reading time is necessary for designing VMS message phase and duration. The drivers’message reading time depends on various factors, such as the number of information units, the number oflines, character height, drivers’ travel speed, and driver characteristics. In this study, a portable VMS(PVMS) was specially manufactured for the study of VMS message reading time, which has three lineswith eight characters per line. Various field experiments were conducted using this portable VMS toobtain drivers’ message reading time with respect to the above causal factors. The relationships betweenthe drivers’ message reading time and various causal factors were statistically tested by ANOVA. Also,regression modeling techniques were applied to develop an estimation model for drivers’ message readingtime. By the final established model, it is shown that the message reading time is affected by the numberof information units, drivers’ travel speed, gender and age group (179 words).