ROADSIDE FEATURES TEST MATRICES

Testing the interaction between vehicles and roadside features should lead to improved roadside safety, and desirably, to more cost effective roadside safety designs. To achieve both of these results, the testing that is undertaken must have relevance to service conditions, and the criteria used to evaluate the test results must take into account both human tolerances to impacts and what is technologically practicable. In order to be relevant, testing must be conducted with vehicles and with approach speeds and angles that are representative of the upper severity limit of a large portion of accident conditions experienced in the field. The current NCHRP Report 230 tests for longitudinal barriers miss the mark a little in this regard. Also, the bus tests that are in NCHRP Report 230 are not representative of vehicles that account for a significant portion of the heavy vehicle barrier accidents, namely, truck semi-trailers. The purpose of NCHRP Report 230 was not to serve as guidance for the acceptance of roadside features. However, it has become the basic document on the subject. In the next writing of NCHRP Report 230 we had better recognize this fact and give much more thought to the recommended design (acceptance) delta V's and do more to explain what they mean.