Capabilities and Performance
Unlike
active safety systems, such as
automatic emergency braking(AEB), that intervene only momentarily when necessary to help prevent a collision, active driving assistance systems provide continuous support intended to make driving easier—for instance, when you’re on a long, boring highway drive or when you get stuck in a slow-moving traffic jam. For this category, we judged how well each system’s lane centering assistance (LCA) kept the vehicle in the center of the lane, as well as how smoothly and intuitively the adaptive cruise control (ACC) could adjust its speed behind other cars.
When it comes to LCA, the systems from Ford, Mercedes-Benz, and Tesla all gave smooth steering inputs and did a good job of keeping the car at or near the center of the lane on both straight and curvy roads. This type of performance gives confidence to the driver that these systems are highly capable.
The previous version of the
Hyundai/
Kia/
Genesis Highway Driving Assist system was dinged for its less capable steering assistance, which caused the vehicle to ping-pong back and forth between the lane lines—even though it’s intended to stay near the center of the lane. At times it also moved uncomfortably close to a vehicle in an adjacent lane, and our testers noted that occasionally the system was incapable of keeping the vehicle within the lane through curves. The updated Hyundai/Kia/Genesis system—called Highway Driving Assist 2 (evaluated on a Hyundai
Ioniq 6)—performed much better thanks to its substantially improved LCA system, which no longer struggles to keep the vehicle near the center of the lane.
The Jaguar/Land Rover Adaptive Cruise w/Steer Assist (tested on a Land Rover
Range Rover Sport) performed the worst of any system at keeping the vehicle centered, or even within the lane, on city streets. There were many times the system would suddenly go into a “standby” mode and stop giving steering assistance, and then depart the lane. Other times the steering-assistance remained engaged but the driver still had to intervene to keep the vehicle from crossing over a lane line. It faired much better on the highway—in fact, it almost felt like an entirely different system.
Volvo/Polestar’s Pilot Assist system lost points because it frequently goes into “standby” mode—which is when the system is not giving steering assistance—without a clear warning to the driver. The periodic mode changes create uncertainty as to whether the system is actively providing steering assistance or not, resulting in the driver frequently looking at the instrument panel for verification rather than keeping their eyes on the road.
The Mercedes and
Lexus/
Toyota ACC systems scored top marks for their well-tuned following-gap distance settings. Our testers found the closest setting to be comfortable in high-traffic areas while still not allowing so much space that other vehicles would continually cut in ahead. We also like that the Mercedes and Subaru ACC systems have settings that allow the driver to adjust the deceleration and acceleration force with which it slows down and speeds back up for traffic ahead.
BMW’s Driving Assistance Professional and GM’s Super Cruise have a driver monitoring camera that ensures the operator is looking at the road ahead when the ACC system brings the vehicle to a full stop, for up to 30 seconds. This provides the convenience of a stop-and-go feature in most traffic jam situations, without the hassle of having to re-engage ACC once traffic ahead starts moving forward again. The camera is there as a safeguard to ensure that drivers are watching the roadway. Most of the other systems change the ACC mode to standby after the vehicle has been stopped for just a few seconds, which eliminates the benefits of using ACC in stop-and-go traffic.
