Automotive researchers at AAA found that over the course of 4,000 miles of real-world driving, vehicles equipped with active driving assistance systems experienced some type of issue every eight miles, on average.

Researchers noted trouble with the systems keeping the test vehicles in their lane and coming too close to other vehicles or guardrails. AAA also found that active driving assistance systems, those that combine vehicle acceleration with braking and steering, often disengage with little notice — almost instantly handing control back to the driver.

Active driving assistance, classified as Level 2 automation, is the highest level of ADAS available on vehicles today. This means for a majority of drivers, their first or only interaction with vehicle automation is through these types of systems, which according to AAA, are far from 100% reliable.

AAA tested the functionality of active driving assistance systems in real-world conditions and in a closed course setting to determine how well they responded to common driving scenarios. On public roadways, nearly three-quarters (73%) of errors involved instances of lane departure or erratic lane position.

While AAA’s closed-course testing found that the systems performed mostly as expected, they were particularly challenged when approaching a simulated disabled vehicle. When encountering this test scenario, in aggregate, a collision occurred 66% of the time and the average impact speed was 25 mph.

“AAA has repeatedly found that active driving assistance systems do not perform consistently, especially in real-word scenarios,” said Greg Brannon, director of automotive engineering and industry relations. “Manufacturers need to work toward more dependable technology, including improving lane keeping assistance and providing more adequate alerts.”

“Active driving assistance systems are designed to assist the driver and help make the roads safer, but the fact is, these systems are in the early stages of their development,” added Brannon. “With the number of issues we experienced in testing, it is unclear how these systems enhance the driving experience in their current form. In the long run, a bad experience with current technology may set back public acceptance of more fully automated vehicles in the future.”