With the multitude of driver assist technologies like blind spot warning and lane keep assist, the question now beckons: which tech actually prevents accidents?

Based on the latest findings published by the U.S.-based Insurance Institute for Highway Safety (IIHS), it’s clear that technology designed to automatically help vehicles stay in their lanes doesn’t provide the same safety benefit as other advanced safety systems.

The IIHS study examined claims data for BMW vehicles from the 2013 through 2017 model years that were equipped with different levels of BMW crash avoidance packages, some of which included LKA.

According to the IIHS study, automatic emergency braking (AEB) and blind spot warning (BSW) can reduce the frequency of insurance claims due to car crashes, but lane keeping assistance (LKA) systems that can automatically steer vehicles between lane lines don’t appear to offer drivers the same safety advantages.

Still despite the benefits, BSW is seldom included as standard safety equipment on new cars and is instead offered as a stand-alone option or as part of a more expensive package of driver convenience options—even on vehicles where LKA comes standard.

A system with FCW, lane departure warning (LDW)—which alerts a driver when the vehicle crosses over a painted lane line but does not take control of the vehicle’s steering automatically—and AEB reduced collision claims by 5 percent, property damage claims by 11 percent, and bodily injury claims by 16 percent. A more technologically advanced version of these systems available in BMW’s Driving Assistance Plus package reduced claims even more. But the addition of optional LKA did not lead to a further reduction in claims.

This echoes an earlier study by Consumer Reports (CR) where they believed that forward collision warning (FCW), AEB, and BSW should come standard on all trim levels. To be named a CR Top Pick, a vehicle must have FCW and AEB with pedestrian detection as standard equipment on all trims, but doesn’t add points to a vehicle’s Overall Score for LDW or LKA.

The IIHS study shouldn’t stop automakers from trying to improve their LKA systems though. That said, they’re reiterating that AEB and BSW should be made standard on new vehicles as well.