The rural deployment of dynamic message signs (DMSs) has been more limited than its deployment in urban areas because of the more dynamic nature of traffic conditions and heavier traffic volumes. However, Missouri Department of Transportation (MoDOT) was awarded a rural safety improvement program (RSIP) grant in 2008 to deploy DMSs and closed-circuit television (CCTV) cameras on some rural segments of highway in the southeast region of Missouri. The University of Missouri performed an evaluation of the deployments with a focus on obtaining the perception of motorists toward DMSs in rural areas, evaluating the impact of DMSs in alerting drivers of an upcoming work zone, and evaluating the impact of DMSs in diverting traffic to a detour route during full freeway closure.
A survey was deployed during the bridge closure in order to get a better understanding of motorists' perceptions and responses to the information provided by the DMSs, as well as basic demographic questions. Traffic data was collected during and after the bridge closure. Based on traffic flow data and survey results, a simulation model was built to evaluate the DMS benefits achieved for various percentages of drivers receiving their detour information solely from DMS.
Because it cannot be known exactly how many drivers took the detour route solely based on the information provided by DMS, multiple percentages were used to calculate a plausible range of benefits acquired through the use of DMS to provide detour information.
- Survey results indicated that 41 percent of drivers surveyed learned about the detour route solely from DMS, providing approximately $21,365 in potential benefits over the closure.
- Total travel time savings ranged between 35.4 and 394.4 hours, which translates to between $5,163 and $55,929 over the three day bridge closure project.