The toughest crash test is getting even harder

What's arguably the toughest crash test in US automotive safety trials is getting an upgrade, with a new version of the small overlap test announced. IIHS, the Insurance Institute for Highway Safety, is adding a second version of the challenge that will be focused on front passengers rather than the driver. It'll make it even tougher for automakers to score what has become a coveted safety award.

While the NHTSA (National Highway Transport Safety Administration) has its own battery of crash tests that all US cars must satisfy, the IIHS has been running its own extra tests for several decades. The Institute was set up by three of some of the largest automotive insurers back in 1959, and began crash testing cars itself in 1992.

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Its become most notorious, though, for the small overlap front test. Added to the roster in 2012, it's one of two front-collision challenges IIHS pits cars against: vehicles are driven at 40 mph into a 5 foot tall, rigid barrier, which hits 25-percent of the front of the car, biased toward the driver's side. It's intended to simulate the impact of hitting an oncoming vehicle or a tree or utility pole.

When the test was launched, the results were surprising – and concerning. Unexpectedly, although vehicles had been designed to handle oncoming collisions, some struggled when the force of the impact was concentrated on such a small area. It forced a change in automotive safety design.

Now, the IIHS is adding a second version of the test that's focused on the passenger. Citing concerns that some automakers have been focusing more on driver-side protection than on parity on both sides of the front of the car, the Institute will now run a passenger-side small overlap front test program on all vehicles it tests. They'll need to get a good or acceptable rating there, in order to qualify for a 2018 TOP SAFETY PICK+ award.

"IIHS engineers initially focused on driver-side protection for a simple reason: Every vehicle on the road has a driver, future advances in self-driving cars notwithstanding, but not every vehicle has a passenger," the organization said of the change. "It also was clear that what works for small overlap protection on the left side might not work on the right, since vehicles are to a certain extent asymmetrical."

Early testing of 2014-16 model year small SUVs found that not all with good driver-side ratings fared so well on the passenger-side test. Indeed, only two of the nine SUVs tested scored "good" ratings. Four managed "acceptable" while two were "marginal" and one "poor".

The results are better for the 2017-18 midsize sedans IIHS has just tested. None had "poor" or "marginal" ratings in the new test, in fact, though five cars did show issues with inconsistent airbag protection.

Of course, there's a reason driver-side testing is still most important for the front overlap test: it's far more common for collisions with oncoming cars to strike the driver's side. Nonetheless, with IIHS giving the passenger side equal weighting if manufacturers want to get the best safety sticker, it seems both sides of the car will benefit from the greater attention to crashworthiness.