TTI Research Supervisor: Sun Hee Park Assistant Research Scientist Texas A&M Transportation Institute Texas A&M University System TAMU 3135, College Station, Texas, 77843-3135 (979) 317-2688 [email protected]
Pooled Fund Technical Representative: Micheal Hills Alaska Department of Transportation & Public Facilities [email protected]
ABSTRACT
This report provides guidance for the treatment of bridge rail ends on low-speed, low volume (LSLV) roads at sites with geometric constraints. Based on federal guidelines and supporting research, the installation of end terminals, transitions, or crash cushions is considered risk-beneficial for bridges with posted speed limits above 30 mph. However, conventional systems typically require a minimum installation length of 37.5 feet, which is often impractical in constrained environments.
To address these limitations, the research team collected LSLV-related current practice data from state agencies and conducted a cost-benefit analysis. Using this information, finite element modeling and simulation were employed to develop compact, non-proprietary attenuator designs as short as 36 inches, evaluated under MASH Test Level 1 (TL-1) conditions.
Although full-scale crash testing was not performed, simulation results demonstrated that the proposed designs significantly reduce occupant risk factors compared to blunt-end impacts— particularly in terms of occupant impact velocity and ridedown acceleration.
This report includes design recommendations intended to enhance safety at bridge ends where space and geometry constraints prevent the use of conventional crash-tested end terminals or crash cushions.
