Lasers, radar, cameras, or a combination are used to keep a constant, safe following space between your car and the car ahead. If highway traffic slows, some adaptive cruise control (ACC) systems will bring the car to a complete stop, then bring it back up to speed when traffic gets going again. Others only work at certain speeds.

(Read our special report, "The Positive Impact of Advanced Safety Systems for Cars.")

Which Brands Do ACC Best?

Most Satisfying: Ninety-two percent of Tesla owners were very satisfied with their ACC system, the highest among all brands. An owner of a 2016 Tesla Model S said ACC makes driving much easier. “It is highly reliable and keeps me at a consistent, safe distance from the car in front of me. This makes the driving experience safer, less fatiguing, and more relaxing.” Subaru holds the second spot at 82 percent very satisfied.

Least Satisfying: Even among the least satisfying brands for ACC, most owners were pleased with the benefits. The lowest-ranked brands—BMW, Chevrolet, and Acura—rated at 66, 68, and 69 percent very satisfied, respectively. An owner of a 2014 BMW X5 liked the system overall but complained that it “overreacts, really slowing down a lot when a car pulls in front. And it’s extremely slow to recover speed once that car has moved out of the way.”

False Alerts: The system does not give alerts or warnings.

CR’s Take: ACC isn’t designed to prevent crashes, but it’s a great system for the highway, reducing some of the stress involved with driving. It also helps prevent tailgating. ACC systems often include FCW, which not only makes the car safer but also further reduces driver stress.

Adaptive Cruise Control

Guide to Advanced Safety Systems

We tell you which safety systems owners like, and the brands that do them best.