Evaluating the Effectiveness of Dynamic Speed Display Signs.

摘要

This study investigates the impact of dynamic speed display signs (DSDSs) on drivers speed-related behavior. A survey questionnaire regarding attitudes and reactions to DSDSs on different road classes was distributed to Maryland drivers of different ages and socioeconomic backgrounds. In addition, the research team collected vehicle speed data upstream and downstream of the DSDS location on different corridors. The data was collected with a portable Trax Flex High Speed Counter, which records vehicles length, speed, and number of axels as they pass over the devices tubes on the road. The speed data was collected on three roads with different speed limits: 25 mph, 35 mph, and 45 mph. Conventional statistical analysis, Bayesian network, and planned behavior theory were applied to assess the DSDS effectiveness with reducing speed. To investigate the shortterm and long-term effects of the DSDS, the research team collected the data in different periods (few days to few months) after the installation. Furthermore, the effective distance for the DSDS was investigated. Two different sizes of the DSDS were used to find the impact of size on drivers compliance.