Highway Construction Work-Zone Safety: Effectiveness of Traffic-Control Devices

Pavement preservation is a proactive approach to maintaining existing highways. Freeway-preservation projects typically require construction workers to conduct their work in close proximity to ongoing high-speed traffic. This exposure creates a dangerous situation for both workers and passing motorists. A recent study funded by the Oregon Department of Transportation (ODOT) implemented and evaluated different types of traffic-control devices on highway-preservation projects to reduce vehicle speeds and create safer work zones. The study implemented combinations of multiple traffic-control devices [speed-limit (“Speed 50”) signs, portable changeable message signs (PCMSs), and radar speed displays] in two case study projects and evaluated their effects on vehicle speed. The researchers used fixed-location sensors and probe vehicle runs to collect data on traffic speed. The results indicate that using a combination of PCMSs and radar speed displays is the best choice. Although data from the probe vehicle runs could not be used for statistical analysis because of limitations on the number of runs conducted, the data provide a vivid and direct view of how individual motorists behave in a construction work zone. The study also provides valuable insight into the effectiveness of the traffic-control measures that contractors can use to design safety into their work operations and further improve the safety in work zones.