The Use of Dynamic Message Signs (DMSs) on the Freeways: An Empirical Analysis of DMSs Logs and Survey Data

Document pages: 18 pages

Abstract: Thisstudy evaluates the Dynamic Message Signs (DMSs) use to dissipate incidentinformation on the freeways in Las Vegas, Nevada. It focuses on the DMSsmessage timing, extent, and content, from the operators’ and drivers’perspectives, considering the variability in drivers’ freeway experience.Two-week incidents data with fifty-nine incidents, DMS log data, and responsesfrom a survey questionnaire were used. The descriptive analysis of theincidents revealed that about 54 of the incidents had their information postedon the DMSs; however, information of only 18.6 of the incidents was posted ontime. The posted information covered the incident type (54.2 ), location(49.2 ), and lane blockage (45.8 ), while the expected delay or the time theincident has lasted are rarely posted. Further, the standard DMSs are the mostpreferred sources of traffic information on the freeway compared to the traveltime only DMSs, and the graphical map boards. The logistic regression appliedto the survey responses revealed that regular freeway users are less likely totake an alternative route when they run into congestion, given no other information is available. Conversely, when givenaccurate information through DMSs, regular freeway users are about 2.9times more likely to detour. Furthermore, regular freeway users perceive thatthe DMSs show clear information about the incident location. Upon improving theDMSs usage, 73 of respondents suggested that the information be providedearlier, and 54 requested improvements on congestion duration and length information.These findings can be used by the DMSs operators in Nevada and worldwide toimprove freeway operations.