News cars already get smashed in the front and the back, sideways and from above, in a battery of tests that has made vehicles safer than ever. But people still die in crashes even in these very safe new cars, so the Insurance Institute for Highway Safety (IIHS) has cooked up another way to demolish cars to test an overlooked type of crash that catches just the front edge of a car.
The IIHS already employs an offset frontal crash test, a side-impact test, a rear-impact test, and a roof-crush test to determine its Top Safety Pick award. These are not the U.S. government's official tests; the National Highway Traffic Safety Administration does those. But scoring an "acceptable" or a "good" on the IIHS tests is necessary to earn a recommendation from the influential Consumer Reports (and to boast in commercials of being a top safety pick), so carmakers take these tests very seriously.
The new test is called a small offset frontal crash test. Currently, NHTSA does a frontal crash test that effectively rams a car into a wall at 35 mph to test head-on hits. This offset front crash test is more realistic because few head-on crashes see the cars perfectly lined up with each another. When they are offset, which is what happens when drivers swerve to avoid the impact, the crash force gets concentrated in just the part of the car that's hit.
The IIHS's existing offset frontal crash test sees a car plow straight into a crushable barrier (designed to replicate a collision with another car) at 40 mph, with the force concentrated on 40 percent of the front end. For the new test, that impact strikes just the corner of the car, concentrating all the force on only 25 percent of the front end. That focuses all the energy in a part of the car where there is typically no frame structure to absorb the blow, making it a tougher safety challenge for new cars.
And because the crash hits the front corner of the car, the vehicle pitches sideways on impact, rotating around the point of impact. Safety systems are designed to protect against direct front or side impacts, so they may not respond appropriately for this kind of crash, where the driver would be thrown sideways even though there was no direct side impact.
The IIHS developed this test after studying late-model cars that scored well in its tests but still suffered fatal accidents. Cars are safer than they've ever been, yet about 10,000 fatalities a year involve frontal crashes, according to the IIHS, and about a quarter of those crashes fall in the category of small offset collisions with either other cars or objects such as trees and poles. "These are severe crashes, and our new test reflects that," noted IIHS president Adrian Lund.
Because cars haven't been crash-tested in exactly this way before, the results have been scattershot. The Acura TL and Volvo S60 both earned "good" scores. (Volvo, it turns out, already does similar testing, so the S60 was prepared. ) Other safety stalwarts from carmakers such as Mercedes-Benz didn't fare so well. In the first round of tests, the IIHS saw the Volkswagen CC's driver's door ripped clean off the car.
Car companies will start developing new autos with this test in mind, but that probably means adding additional steel armor to the front corners. This will compound the weight escalation seen in new cars lately. Carmakers have spoken extensively about finding ways for new models to weigh less than their predecessors, but increasing tough crash tests make that difficult. This extra weight has made improving gas mileage an even tougher chore, but neither carmakers or consumers seem willing to trade safety for greater efficiency through lighter weight.
Honda has said it's building some 2013 cars with the test in mind; the new Accord might be among the first cars to do so. But that doesn't mean other cars are doomed to bad scores until they are totally redone. IIHS says many subtle details can improve the scores of existing models. Programming the side airbags and curtains to deploy during these kinds of crashes is one way. Among 13 entry luxury models tested so far, the side airbags did not deploy in the test because they are primarily intended as protection in side impacts.
In the longer term, carmakers will probably redesign airbags to protect against this kind of crash. Current side airbags and curtains do not extend very far forward because they anticipate a T-bone type of crash that pitches the occupant sideways. In these small overlap frontal tests, the crash-test dummy tends to pitch diagonally forward toward the windshield pillar, falling into a gap between front and side airbags.
Seatbelts will change too. Volkswagen and Mercedes suffered poor performance because of their seatbelt programming. Their belts are programmed to have some give in frontal crashes to reduce the loads placed on the occupant's chest. But in the small overlap test, that give allowed the test dummies to move too far forward in a cabin that is collapsing backward. Minor tweaks to belts, bags, and software will help many cars better protect occupants and earn decent ratings until they receive the additional body armor.
Carmakers don't have long to adapt. For the 2013 model year, the existing rules remain in place for getting a Top Safety Pick award (though cars such as the TL and S60 will get some kind of asterisk denoting their good performance in the new test). Then, for 2014, the new test will be part of the requirements.