Back seat safety: Ford, Subaru, Tesla score highest in IIHS crash test

There is much room for improvement when it comes to the safety of back seat passengers in midsize crossovers, a new Insurance Institute for Highway Safety study shows.

IIHS updated its moderate overlap front crash test by adding a rear passenger behind the driver to examine rear passenger protection. This led to only four of the 13 tested midsize crossovers earning a "good" rating: the Ford Explorer, Ford Mustang Mach-E, Subaru Ascent and Tesla Model Y.

The results show that knowledge of back seat safety isn't limited to legacy automakers, Raul Arbelaez, vice president of the IIHS research center, told Automotive News.

"There is no secret sauce here. We know what needs to be done to properly restrain occupants and give them higher levels of protection," Arbelaez said. "By having this new test criteria, it will force the auto industry to pay more attention to this crash mode."

The Chevrolet Traverse, Toyota Highlander and Volkswagen Atlas earned "marginal" ratings in the test. The Honda Pilot, Hyundai Palisade, Jeep Grand Cherokee, Jeep Wrangler four-door, Mazda CX-9 and Nissan Murano earned "poor" ratings.

"All these vehicles provide excellent protection for the driver," IIHS President David Harkey said. "But only a handful extend that level of safety to the back seat."

The risk of fatal injury is 46 percent higher for belted occupants in the rear seat in vehicles model year 2007 and beyond simply because restraint technologies have improved in the front seat only, a release said. IIHS updated its test after seeing back seat safety improvements trail behind those for front-seat occupants.

The back seat isn't getting more dangerous, but rather safety advancements haven't kept up with front-seat advances, Arbelaez said.

The new test uses a dummy that represents a small woman or 12-year-old to focus on avoiding injuries typically seen in back seat occupants.

To earn a good rating, sensors must not indicate excessive risk of head, neck, chest, abdomen or thigh injury. Video footage and greasepaint on the dummy's head are used to showcase that restraints prevent the head from hitting the interior or the front seat. Restraints must also prevent the body from sliding underneath the lap seat belt. Pressure sensors monitor the belt on the dummy's torso to gauge chest injury risk.

"Zeroing in on weaknesses in rear seat safety is an opportunity to make big gains in a short time, since solutions that are already proven to work in the front can successfully be adapted for the rear," IIHS Senior Research Engineer Marcy Edwards said. "The four good ratings in this round of testing show that some automakers are already doing it."

Despite receiving a rating of "good," Ascent and Explorer measurements indicated a slight risk of head or neck injuries for the rear dummy. The dummies in the Ascent, Explorer and Model Y approached the back of the front seat, which is a head injury risk.

The Atlas indicated a slight risk of head or neck injury, the seat belt tension was high and the rear dummy's head came close to the front seatback.

The Highlander indicated a slight risk of head or neck injury and the rear dummy's belt moved to the abdomen, increasing risk of injury.

The Traverse showcased a more significant risk of head or neck injury as well as high seat belt tension, which increases the risk of chest injury.

Rear dummy measurements showcased a high risk of head or neck injury in the CX-9, Grand Cherokee, Murano, Palisade and Pilot. The rear seat belt tension was also high in the CX-9, Grand Cherokee, Palisade and Pilot.

The Wrangler showcased a significant risk of head or neck injury. It lacks a side curtain airbag in the rear and the lap seat belt shifted to the abdomen.

The rear passenger dummy's head almost hit the front seat in the Murano. In the Grand Cherokee, the rear dummy's head dead-ended between the window and the airbag after rebounding from impact, increasing the risk of injury from the hard interior or objects outside the vehicle.