There are no true self-driving cars for sale in America today. But most new cars include so-called automated driver assists — partial automation systems that help keep a car in its lane or brake to avoid an obstacle.
Self-driving advocates say they’re the first step toward a future where self-driving cars are safer than human drivers.
But new research says they’re no safer yet.
“Crash records and insurance data offer little evidence that partial automation systems are preventing collisions,” says the Insurance Institute for Highway Safety (IIHS).
Your Insurance Company’s Lab
The IIHS is a safety laboratory funded by a large group of car insurance companies. Your insurance company has a financial motive for making accidents as rare and minor as possible, and the IIHS is how it tries to do that.
The institute conducts its own crash tests, generally considered more rigorous than government crash tests. It also studies accidents to understand how they happen and what helps prevent them.
For this study, IIHS researchers examined data from insurance claims for vehicles with and without driver assists, such as automatic emergency braking and forward collision warning.
Systems Are Common, but Not All Effective
Such systems have grown common in recent years. Nearly every car on the market in 2024 has some version of automatic emergency braking to reduce forward collisions, for instance.
But not every system is effective. Studies have found automatic emergency braking less effective than advertised. Many systems are much less effective at night.
The federal government recently announced a new rule mandating the technology in all new cars by 2029. Industry watchers believe the mandate will require automakers to improve their systems, as they’ll soon have to pass tests that measure their effectiveness.
IIHS Studied Nissan, BMW as Examples
Researchers investigated crashes involving BMW and Nissan vehicles. The IIHS says the companies’ products “have been on the road for a number of years” with and without partial automation systems.
The study found that automatic emergency braking conferred some safety benefits. But systems like smart cruise control (which can accelerate and brake to keep pace with traffic) and lane-keeping systems (which can navigate curves to keep a car in the center of its lane) did not.
The IIHS found that Nissan Rogue models’ lane centering and adaptive cruise control provided “no additional benefit” beyond what automatic emergency braking could do.
Similarly, “there were no additional statistically significant reductions associated with BMW’s Driving Assistant Plus partial automation system” for BMW vehicles.
Systems Could Still Be Useful
The data doesn’t mean that partial automation provides no benefits, researchers say. Instead, IIHS President David Harkey says, “Everything we’re seeing tells us that partial automation is a convenience feature like power windows or heated seats rather than a safety technology.”
Car shoppers “should not confuse it for a safety feature,” adds Jessica Cicchino, senior vice president for research at IIHS.
