Report Result

TRP-03-478a-25

Mojdeh Pajouh, Scott Rosenbaugh, Mohammadreza Rajaee, Ethan Galusha, Ronald Faller

2025-05-16

The Hawaii Department of Transportation (HDOT) utilizes the Hawaii Modified Natchez Trace Bridge Rail to safely redirect vehicles on bridges. However, the crashworthiness of this bridge rail has not been investigated under current impact safety standards. This report documents one full-scale crash test conducted to evaluate the safety performance of HDOT’s Hawaii Modified Natchez Trace Bridge Rail. The system had a mounting height of 36 in. and varied in width from 18¼ in. at the top to 24 in. at the bottom. The bridge rail design utilized 12-in. long by 12-in. wide posts that were spaced 90 in. apart on centerlines and mounted on top of a 10-in. high curb. The test installation had an overall length of 70 ft – 7 in. and incorporated three railing segments with ½-in. expansion joints placed at the end of each rail segment. Test no. HNTBR-1 was conducted according to the Manual for Assessing Safety Hardware (MASH) test designation no. 3-11. In test no. HNTBR-1, a 2270P vehicle impacted the Hawaii Modified Natchez Trace Bridge Rail at a speed of 62.3 mph and an angle of 25.0 degrees. The vehicle was safely contained and redirected with minimal damage to the bridge rail. However, the occupant compartment intrusion at the wheel well and toe pan measured 12.7 in., which exceeded the MASH limit of 9 in. Thus, test no. HNTBR-1 failed to satisfy the safety standards of MASH. The system will need to be redesigned and re-tested in future research efforts.

Highway Safety, Crash Test, Roadside Appurtenances, Bridge Rail, Compliance Test, MASH 2016, Test Level 3, Modified Natchez Trace Bridge Rail

TRP-03-478a-25.pdf