Assessment of impact of variable message signs on traffic surveillance in Kuala Lumpur

Variable message signs (VMS), also known as changeable message signs (CMS) or dynamic message signs (DMS), are traffic control devices to communicate with motorists. A VMS is generally used to inform motorists the roadway, traffic, or weather conditions. It is also used to display travel times and public service announcements. This study attempts to utilize archived traffic data from the MRR1 freeway area in Kuala Lumpur to assess the accuracy with which VMS display travel time estimates, and driver response to display messages of varying lengths and formatting. Results show that usage of variable message signs reduces the average travel times during the duration of the incident until the clearing of the resulting congestion by a significant amount. Under the presence of VMS, there is a significant shift of people from higher travel times in case of incident to lower travel times. The results demonstrate that VMS has no significant impact on gap but occupancy comes down.