Online Surveys Distributed to Travelers in the Las Vegas Area Revealed Drivers’ Preferences for Dynamic Message Signs’ Message Format and Their Likelihood to Change Their Behaviors in Response.
Las Vegas, Nevada, United States
The Use of Dynamic Message Signs (DMSs) on the Freeways: An Empirical Analysis of DMSs Logs and Survey Data
Summary Information
Dynamic Message Signs (DMS) are a tool widely used by transportation agencies to disseminate information to the traveling public. One common application is providing travel time information upstream of a congested area with information to travelers about an alternate route. Las Vegas has 82 DMS signs on their freeways and arterials. This comprehensive study aimed to evaluate the effectiveness and usefulness of DMSsin the Las Vegas freeway system. The research incorporated detailed log data from the DMSs themselves as well as survey responses from drivers to gain insights into user preferences and satisfaction levels.
METHODOLOGY
The study utilized two weeks of log data in December 2014, detailing 59 incidents on Las Vegas freeways and the corresponding information displayed on DMSs, allowing analysis of how much incident information was disseminated via DMSs and the timeliness of messaging. Then over two months, a survey was distributed which collected 238 responses. The survey asked if drivers preferred incident information, just route travel times, or a congestion map on the DMS. It then asked how likely drivers were to choose an alternate route, and finally asked broad questions about how to improve general road use satisfaction.
FINDINGS
- Regular freeway users were 2.9 Times More likely to take an alternate route when accurate information is provided.
- The analysis of incident and DMS log data revealed that DMSs effectively informed travelers about incidents 54.2 percent of the time.
- Survey results showed that 70 percent of respondents preferred standard DMS with incident information (e.g., “Major crash, Sahara N I-15, 2 Right Lanes Blocked”) than travel time only DMSs, and the graphical map boards.
- Majority of the respondents (73 percent) requested that congestion information be displayed as early as possible by showing it at more than one DMS location upstream.
