A recent study comparing vehicles with and without rear automatic emergency braking (AEB) found that vehicles equipped with the technology had 28% fewer property damage liability claims and 10% fewer collision claims, according to the Highway Loss Data Institute (HLDI).

Rear AEB was the standout feature in HLDI’s annual compilation of its research on the impact of crash avoidance technologies, an updated analysis from the Highway Loss Data Institute (HLDI) shows. Collision insurance covers damage to the insured driver’s vehicle, while property damage liability insurance covers damage to the other vehicle involved in a crash when the insured driver is at fault.

“We haven’t seen that kind of reduction in claims for vehicle and other property damage from any other advanced driver assistance system,” said HLDI Senior Vice President Matt Moore.

However, the impact of rear AEB on injury crashes was relatively small, which makes sense based on the type of crashes the technology is designed to avoid, the study found.

“Backing crashes generally happen at lower speeds than front-to-rear crashes,” Moore said. “That means they’re less dangerous, but the costs from vehicle damage can add up.”

Low-speed backing crashes represent a substantial portion of insurance claims, an HLDI study found. Collision claims with rear damage of less than $2,000 accounted for 17% of all collision claims and over $8 billion in estimated damage during calendar years 2010 to 2017.

In comparison, HLDI has found that front AEB reduces the frequency of collision claims by 3% and property damage liability claims by 14%. However, it slashes the frequency of bodily injury liability claims, which are for injuries that at-fault drivers inflict on occupants of other vehicles or others on the road, by nearly 25%.

Both front and rear AEB use sensors like cameras or radar to detect when the vehicle is getting too close to an obstacle and automatically apply the brakes to avoid or mitigate collisions.

HLDI also found that two other features designed to prevent backing crashes, parking sensors and rear cameras, which are both more common than rear AEB, were much less effective. Data from seven other manufacturers showed that rear cameras reduced the frequency of property damage liability claims by 5%. Parking sensors also reduced the frequency of property damage liability claims by 5%.

“Claims data show that collision avoidance technologies that automatically intervene to prevent or mitigate crashes are more effective than warning-based systems,” said Moore, noting that forward collision warning is also associated with smaller claims reductions than front AEB.

Aside from rear AEB, front AEB and forward-collision warning are the only stand-alone driver assistance features analyzed by HLDI that show double-digit percent reductions in claim frequency under any type of coverage.