In 1993, the Federal Highway Administration adopted a policy that requires all roadside features placed within the clear zone to be evaluated according to the guidelines contained in National Cooperative Highway Research Program (NCHRP) Report 350. Variable message sign trailers and arrow board trailers have never been tested under these safety evaluation guidelines. A full-scale crash test and a review of work zone accident studies clearly indicate that these trailers are a serious roadside hazard and they are struck in approximately 15% of all work zone intrusion accidents. An attenuating cushion that safely treats the full range of these trailers was developed. Two full-scale crash tests of the trailer attenuating cushion were conducted to verify that the new designs meet NCHRP Report 350 guidelines. The new safety treatments are believed to be relatively inexpensive to build and easy to deploy. The new systems should reduce the severity of many run-off-road crashes without a major increase in the cost of using variable message signs and arrow boards.
Abstract