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Don’t rely on car safety systems in bad weather, warns American Automobile Association


Features such as automatic braking and lane assist become less effective in the rain.

The American Automobile Association (AAA) is warning drivers across the country not to rely too much on advanced car safety systems, such as automatic braking and lane change assist systems, in bad weather.

New research from the organization has revealed that heavy rains interfere with the proper functioning of security functions, which can lead to performance issues.

During the AAA experiments, vehicles equipped with automatic emergency braking, which were traveling at 35 mph, collided with a stopped vehicle a third of the time.

“Often times these systems are tested under somewhat perfect conditions,” Greg Brannon, director of automotive engineering and industrial relations at AAA, told ABC News. “But the reality is that drivers don’t drive in perfect conditions.”

In the experiment, AAA simulated rain and other environmental conditions, such as insects and dirt, to measure the performance impact of various advanced driver assistance systems (ADAS).

To simulate precipitation, AAA engineers designed a system that used a reservoir to hold water at the top of the test vehicle’s loading area. The system was connected to a nozzle positioned above the windshield, so that the spray jet covered the entire windshield.

“We created a device that allowed the windshield to essentially feel what it would do in a rainstorm,” said Brannon.

The AAA also found that cars equipped with lane keeping assist went out of their lane 69% of the time.

“These are pretty, pretty substantial and surprising results for something that’s on a lot of cars today,” Brannon said.

The tests were conducted with five different vehicles, including the 2020 Buick Enclave Avenir with automatic emergency braking and lane keep assist, a 2020 Hyundai Santa Fe with front collision assist and lane keep assist, a 2020 Toyota RAV4 with pre-collision system and lane keeping. lane assist and a 2020 Volkswagen Tiguan3 with front assist and lane assist.

According to the National Highway Traffic Safety Administration (NHTSA), “Driver assistance technologies have the potential to reduce traffic accidents and save thousands of lives each year.

The agency said more than 36,000 people died in motor vehicle crashes in 2019, many of which were linked to human error.

Brannon said consumers should be using advanced safety systems, but not in place of engaged driving. “The most dangerous thing a consumer can do is rely too much on systems.”

“AAA’s advice to consumers who have advanced security systems in their cars is really the same regardless of that system, and that is to drive the car as if the system isn’t there,” said Brannon. “Select a car with the most advanced safety systems available, because they all have tremendous potential to reduce injuries and save lives, and that’s a good thing”

Brannon said drivers should never use cruise control in bad weather, and he advised motorists to slow down.

“Really understand the environment you are operating in and then make sure that you are fully engaged in that driving task,” said Brannon.