Cruise control is the grandparent of all driver aids. It’s been around for decades, but more recently it got a high-tech makeover. Adaptive cruise control can maintain a set speed like conventional cruise control, but it can also vary speed based on traffic flow. This technology can not only make cruise control more useful, it’s also a baby step toward autonomous driving.
What to look for
Adaptive cruise control is also known as dynamic radar cruise control or intelligent cruise control, and automakers have their own brand names for their systems. Regardless of the name, the basic idea is that a car can accelerate or decelerate automatically, based on what other cars around it are doing.
To do that, a car must be equipped with sensors that allow it to detect nearby vehicles and potential obstacles. Most adaptive cruise control systems use radar, although cameras and lidar (which works on the same principle as radar, but with light waves) can be used as well. You can often spot cameras mounted in the grille or behind the windshield; radar units usually sit behind flat plastic panels in the grille. The sensors communicate with a computer that controls the throttle and — sometimes — the brakes and steering.
A basic adaptive cruise control system will only handle acceleration and deceleration, usually by locking onto the car in front with sensors and keeping a set following distance and speed. Some automakers have begun bundling this capability with systems that can brake a car to a full stop, or that provide a limited amount of automated steering to keep the car centered in its lane.
Adaptive cruise control is at the center of the pile on of electronic driver aids that could form the basis for fully autonomous driving. Sensors like radar already deployed in adaptive cruise-control systems will be crucial to autonomous cars, and adaptive cruise control has kicked off the process of automating some parts of driving. We’re nowhere near fully autonomous driving yet, though, and it is important not to mistake adaptive cruise control and other related tech for full autonomy. These systems are designed to help the driver, not drive the car themselves.
This is one technology that cannot easily be retrofitted to an existing car. The complexity of adaptive cruise control systems puts them beyond the reach of the aftermarket. Considering that these systems can mean the difference between a car driving along and smashing into the back of another vehicle, concerns over liability will probably keep adaptive cruise control firmly within the domain of the original equipment manufacturers for the time being.
Who does it best?
It’s no surprise that an automaker known to be obsessed with safety was an early adopter of adaptive cruise control. Volvo was also one of the first automakers to pair the technology with autonomous emergency braking, allowing a car to both automatically follow a vehicle in front and brake if it encounters an obstacle. Volvo’s latest Pilot Assist II system also doesn’t need to track a vehicle ahead, can a keep a car centered in its lane, and can operate at speeds up to 80 mph.
Available on: S90 (standard), V90 (standard), V90 Cross Country (standard), XC90 (standard), and XC60 (Convenience Package).
Subaru’s EyeSight system uses cameras instead of radar, bringing down its cost and making installation of the hardware a bit easier. EyeSight bundles adaptive cruise control with lane-keep assist, a “pre-collision throttle management” feature that cuts the throttle ahead of an anticipated collision, and low-speed autonomous emergency braking.
Available on: Impreza (Premium trim), Crosstrek (Premium trim), WRX (Limited trim), Forester (Premium trim), Outback (Premium trim), and Legacy (Premium trim).
Mercedes offers one of the most comprehensive adaptive cruise control and driver-assistance suites of any automaker. Its latest Distronic Plus system can keep up with traffic, but also brake the car to a full stop in stop-and-go situations. The system will automatically resume driving if the stop is under three seconds; longer stops require a tap of the accelerator pedal or cruise control “resume” button. A steering-assist feature helps keep the car centered in its lane, and certain versions of the system can initiate lane changes
Available on: S-Class (Driver Assistance Package), E-Class (Premium 3 Package), C-Class (Premium Driver Assistance Package), CLS-Class (Driver Assistance Package), SL-Class (Driver Assistance Package), GLC-Class (Premium Driver Assistance Package), GLE-Class (Premium 3 Package), GLS-Class (Driver Assistance Package), and Mercedes-Maybach S650 4Matic (standard).
Tesla’s Autopilot system has attracted its share of controversy, and the name is a bit misleading considering that a human driver must be kept in the loop, but it’s still one of the most advanced systems of its kind. In addition to following traffic and automatically keeping a car in its lane, Autopilot can execute lane changes with the flick of a turn signal, and negotiate some highway off ramps. Tesla’s ability to pull data from cars using the system and launch over-the-air software updates means Autopilot has significant potential to improve over time.
Available on: Model S (optional extra), Model X (optional extra) and Model 3 (optional extra).