AAA Study Finds Driver-Assist Systems Struggle in Bad Weather

author: Vineeth Joel Patel   

With advanced driver-assist features being ubiquitous and operating smoothly in nice weather, quite a few drivers have become used to relying on the systems to handle the majority of driving for them. While that's a bad idea in good weather, it's a really bad idea in bad weather. According to a study conducted by the American Automobile Association, automatic emergency braking and lane keeping assist have a lot of trouble operating properly in rainy conditions.

Bad Weather Affects Safety Systems

Just like humans, a vehicle's safety system has a hard time seeing the road in moderate and heavy rain. AAA conducted closed-course testing where it simulated rainfall for vehicles equipped with automatic emergency braking traveling at 35 mph. During the test, vehicles collided with a stopped car 33 percent of the time. Lane keeping assist did even worse in the test, as vehicles departed their lane 69 percent of the time.

For drivers, this could lead to a dangerous situation when driving in inclement weather. If a driver relies too heavily on the systems, they could get into an accident. The findings are especially noteworthy, as safety systems tend to be evaluated in perfect conditions. The AAA believes that testing standards should incorporate inclement weather, as that's something drivers will encounter normally.

"Vehicle safety systems rely on sensors and cameras to see road markings, other cars, pedestrians and roadway obstacles. So naturally, they are more vulnerable to environmental factors like rain," said Greg Brannon, AAA's director of automotive engineering and industry relations.

Tips To Follow In Bad Weather

It's not like slowing down helped the situation a lot, either. At 25 mph, vehicles with automatic emergency braking still hit a stopped vehicle 17 percent of the time at 25 mph. In ideal conditions, vehicles with lane keeping assist crossed lane markers 37 percent of the time. The AAA's study involved researchers spraying water directly onto the sensors on the cars' windshield. So, the roads remained dry for the most part. The AAA notes that wet roads could result in even higher crash rates.

To conduct its testing, the AAA tested a 2020 Toyota RAV4, Hyundai Santa Fe, Volkswagen Tiguan, and Buick Enclave Avenir.

There is some good news, as the AAA found that dirty windshields or ones with a lot of bugs on them didn't greatly affect a vehicle's sensors. For driving in the rain, the AAA recommends that drivers keep their windshield clean, slow down, avoid hard braking and sharp turning, increase following distance, and avoid using cruise control. These tips, though, don't state the obvious, which is to not rely on driver-assist systems in inclement weather.

Vineeth Joel Patel

Joel Patel has been covering all aspects of the automotive industry for four years as an editor and freelance writer for various websites. When it comes to cars, he enjoys covering the merger between technology and cars. In his spare time, Joel likes to watch baseball, work on his car, and try new foods