ARA Making Road Construction Safer through Engineering ResearchOctober 2011
ARA recently completed a two and one-half year research effort to help state highway agencies (DOTs), tollway and turnpike authorities, private traffic control service providers, and highway contractors improve the safety of mobile lane closures and reduce risk to highway workers and the traveling public of serious and fatal accidents when work is performed on in-service roadways. Funded by the Illinois Department of Transportation (IDOT), the research examined roadwork using trucks, signs, and arrowboards in a continuously moving or intermittent operation, say for pothole repairing, where it is not feasible to setup a static lane closure using cones and drums. The mobile operation is inherently riskier, but very common due to the time and expense of setting up static lane closures.
The research was unique because it collected extensive data by videotaping full-scale field experiments of driver behavior around actual mobile lane closures under a variety of conditions, traffic levels, day/night, urban/rural, and so on, and analyzed the data to determine what factors were causing dangerous conditions and what the field crews could do to improve safety. Importantly, the research team developed recommendations for spacing requirements between traffic control trucks, trucks and workers, and trucks and the upstream warning signs. Previously, the spacing recommendations in most standards were either incomplete or contradictory and references were almost never documented. The figure gives an example of the types of recommendations developed through the research.
The work was highlighted in the June 2011 edition of Safety Today, a supplement to Road & Bridges magazine, a leading magazine for the transportation construction and maintenance industry.
The original project was performed by the Midwest Division of the Transportation Sector, and while that research has ended, the team has received a follow-on project on a related-topic, one that was identified through the original study. The follow-on work will involve the Cognitive Solutions Division, and Transportation expects to stay active in the area and look for other opportunities to perform a similar study for other states and at a national level.