Safe and Effective Speed Reductions for Freeway Work Zones: Phase 2

Freeway preservation projects typically require construction workers to conduct their work in close proximity to ongoing traffic and often reduce traffic flow to a single lane while work is undertaken in an adjacent lane. Due to the short-term nature of these work zones, temporary traffic control measures typically consist of a line of cones, blocker vehicles, and impact attenuators. Work zones place both the workers and passing motorists at risk of injury. The Oregon Department of Transportation conducted a research study to investigate the impact of selected traffic control devices on vehicle speeds within highway paving project work zones. The research study, which follows a similar study conducted a year earlier, centered around two case studies on multi-lane paving projects in Oregon. On each case study, the researchers implemented combinations of multiple traffic control devices (“Speed 50” signs, PCMS signs, and radar speed displays) and evaluated their impact on vehicle speed. The research findings suggest using a combination of reduced speed limit signs, radar speed monitoring displays, and PCMS signs on either trailers or rollers. The results of the present study complement those of the prior study and, combined with the prior study, provide ODOT with guidance on the selection of traffic control measures for freeway preservation projects.