A highway insurance group raised serious questions Tuesday about the bumpers designed to protect drivers who hit trucks from behind.
The evidence is compelling and should, we believe, result in immediate action.
The Insurance Institute for Highway Safety tested the effectiveness of the so-called “Mansfield bars” beneath truck beds that are supposed to prevent passenger vehicles from under-riding trucks in collisions.
The bars, more properly called rear-impact safety guards, were first required on trailers after the 1967 death of actress Jayne Mansfield.
Her convertible plowed into the rear end of a truck in Louisiana as it slowed for another vehicle. Mansfield and the driver of her car were killed.
The effectiveness of the guards was again questioned in 1996 and new standards were adopted, setting a uniform height of 22 inches for the bars.
Interestingly, media accounts from those hearings reported safety advocates urging that a stronger, lower unit be required, which would have cost about $300 per vehicle.
After heavy lobbying by the trucking industry, the final standard required a weaker design that cost less than half as much.
Canada, meanwhile, requires a bar that is 75 percent stronger than the U.S. version, and which the IIHS tests show works.
In the U.S., there has never been a requirement for manufacturers to test their bars.
The IIHS tested several trucks with the U.S. and Canadian equipment. These photos show the dramatic difference.
At speeds as low as 35 mph, a mid-sized Chevy Malibu with a 5-star crash-worthiness rating collapses the bar and the car slides under the truck. The trailer, meanwhile, enters the passenger compartment.
The stronger model stops the car from wedging beneath the truck.
Today’s car frames are designed to gradually collapse and dissipate the energy of a bumper-to-bumper collision.
When a car under-rides a truck, that system is ineffective and the torsos of front-seat passengers collide with the bed of the truck.
“Damage to the cars in some of these tests was so devastating that it’s hard to watch the footage without wincing,” said Institute President Adrian Lund. “If these had been real-world crashes, there would be no survivors.”
The U.S. standard is clearly ineffective.
The National Highway Traffic Safety Administration estimates that 423 people a year die when their vehicles strike the back-ends of large trucks. More than 5,000 other occupants are injured.
The truck trailer makers must do better, and federal regulators should make sure they do.
rrhoades@sunjournal.com
The opinions expressed in this column reflect the views of the ownership and editorial board.
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- A car after a 35 mph crash into a trailer with a weak guard.
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- A car after crashing into a strong guard. The occupant compartment is intact.
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