What is adaptive cruise control?

Less stress in traffic and safety benefits too: adaptive cruise control will automatically keep its distance from any car in front

BuyaCar team
Apr 27, 2021

If you're looking for ways to take the strain out of driving, especially if you spend most of your time on motorways, a car with adaptive cruise control might be your next port of call.

You might have heard of cruise control, it's been a common feature on new cars since the early 2000s, and the standard cruise control systems are perfect for long journeys when the road ahead is clear. They control the accelerator to keep the car travelling at a set speed, so you don't need to keep your foot balanced on the pedal for hours on end. However the car will only ever maintain its speed, so you still need to be alert whenever the time comes to apply the brakes.

Unfortunately, a clear road is a distant dream to millions of British drivers who are often forced to content with congestion, tailbacks and variable speed limits, each of which means disengaging cruise control and taking back full control of the car.

This is where adaptive cruise control comes in. Whereas cruise control simply locks in a constant speed, adaptive systems make use of sensors around the outside of the car to manage distances between you and the car in front, so it's possible to travel pedal-free much more freely in light traffic, although heavy braking will still need to be done by the driver.

Cars with adaptive cruise control are increasingly common, even relatively affordable cars such as the Volkswagen Polo and Ford Fiesta will have models equipped with this incredibly convenient feature. If you're keen to reduce your driving workload, read on for details or head to our BuyaCar search page to start your car buying journey.

What is adaptive cruise control?

Cars with adaptive cruise control can automatically accelerate and brake to maintain a safe distance behind the car in front. When the road ahead is clear, your car will continue at a pre-set speed โ€“ slowing down if a slower car is ahead, and speeding back up when the way is clear.

More advanced systems can also take control in stop-start traffic jams, while some cars will also make use ofย traffic sign recognition, which will adjust the car's speed depending upon the speed limit.

How adaptive cruise control works

To engage adaptive cruise control, you set your desired speed the same way you would with standard cruise control - this is normally a switch on the steering wheel, and the car will travel at that speed as long as the road ahead is clear.

Once the system is active, it will constantly monitor the road ahead with sensors. More basic adaptive cruise control systems use radar alone, but many manufacturers also use cameras to provide more information about any upcoming traffic - these are generally only more on more expensive cars.

The car's sensors should be able to detect any slower vehicles ahead before there's any need to slow down. As the gap closes, adaptive cruise control systems gently slow your car to the same speed until both vehicles are travelling at the same rate, a safe distance apart.

If the vehicle ahead speeds up or turns off the road or into another lane, then your car will speed up until it reaches the pre-set speed again.

Advanced adaptive cruise control systems

Traffic jam assistance

Early cars with adaptive cruise control could only adjust speed within a small range. At slower speeds, drivers had to take control. Many modern systems now include traffic jam assistance that can bring the car to a halt in traffic jams and slowly crawl along when the tailback moves.

Speed recognition

Speed limit recognition is commonly available on cars, although it's often optional. Front-facng cars can identify speed limit signs and display the limit to the driver on a dashboard screen. Some adaptive cruise systems link to this function and automatically reduce the pre-set speed when the car enters a higher or lower limit.

However, the operation of these systems is hit-and-miss. The car may not react quickly enough to motorway speed limits, putting you at risk of being caught by a speed camera when the limit is reduced.

They can also be caught out by speed limit signs on a lorry or a side road, so you may find your car suddenly trying to brake to from 70mph to 40mph on a clear A-Road, which can be alarming for other traffic, to say the least.


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