The appropriateness of test conditions specified in NCHRP Report 350 was assessed. The assessment focused on the basic Test Level 3 and addressed two areas of interest: the effects of higher speed limit on impact speed and the appropriateness of 25 deg for the impact angle. The following conclusions and recommendations were drawn on the basis of the results of the analysis: (a) the current test impact speed of 100 km/h (62.2 mph) should be maintained, (b) the current impact angle of 25 deg for Test 11 of length-of-need sections of permanent longitudinal barriers should be maintained, (c) the test impact angle should be reduced from 25 deg to 20 deg for Test 11 of length-of-need sections of temporary longitudinal barriers, and (d) the test impact angle should be reduced from 25 deg to 20 deg for Test 21 of barrier transition sections. However, the selection of impact conditions is more a policy decision than a technical issue to be resolved in the update of NCHRP Report 350 guidelines.
Abstract