This article examines a safety feature that could prevent many accidents at roadworks, about 4,000 of which occur in Great Britain per year. Accident rates are about 60% higher at roadworks. Mobile lane closures were introduced during the 1980s to facilitate continuous working on high speed roads. They were judged to be cost-effective in certain situations. A `block' or `shadow' vehicle is used at the rear of the roadworks, to protect workers from conflict with mainstream traffic. The vehicle has amber flashing warning lights, and a road sign indicating on which side of the closure main stream traffic should pass. Crash cushions, called `Truck Mounted Attenuators' (TMAs) should be mounted on block vehicles for mobile lane closures on high-speed dual carriageways and motorways. About 1,800 are used in the USA, and about 200 elsewhere. The widespread use of TMAs seems to have considerable safety potential, as they reduce the possibility of under-run, and absorb the energy of impact for the occupants of both vehicles. Their widespread use has been recommended in the USA, after a three-year trial in Virginia which led to a 70% reduction of work zone accidents. There have also been tests in Germany and Japan. Accidents involving collisions with TMAs in the UK showed only minor injuries. The author advocates the wider introduction of TMAs as a very cost-effective part of a package of measures for improved safety at roadworks in the UK.
Abstract