NCHRP Report 350
When it is determined that shielding the hazard with a traffic barrier is appropriate, ensure that the barrier performance conforms to Recommended Procedures for the Safety Performance Evaluation of Highway Features, NCHRP Report 350. This publication outlines minimum crash performance criteria that roadside hardware should meet. NCHRP Report 350 approved devices are required on: all National Highway System (NHS) roads, all roads where daily traffic volumes exceed 6000 vehicles, and on all roads where the design speed is greater than 50 mph. NCHRP Report 350 approved devices are considered crashworthy.