Passenger cars and trucks slammed into a TTI-designed bridge rail in August at speeds never before tested at the Texas A&M Riverside Campus. The vehicles reached 85 miles per hour in tests designed to prepare for high-speed roadways under consideration by the Texas Department of Transportation (TxDOT) in an effort to expand the state’s transportation system.
“TxDOT is investigating very high design speeds between 80 and 100 mph to promote faster and more efficient travel within the state,” says TTI Research Engineer Roger Bligh. “We know how our roadside safety devices react to crashes performed at normal highway speeds, but above 80 mph is not something we have tested before now.”
Two of the high-speed tests involved a bridge rail modified with pipe inserts between a concrete barrier and steel rails. “The energy-absorbing mechanism did its job,” Bligh says. “But, as a result of the tests, we know these faster speeds will require a taller rail in order to ensure stability for vehicles with higher centers of gravity, like pick-up trucks.”
To be deemed successful, the roadside safety device must keep the tested vehicle stable and upright with little intrusion into the passenger compartment.
As part of the TxDOT project, Bligh and his team also tested a guardrail system designed to accommodate high-speed impacts.