This is the first article in a series on modern automotive technology.
Adaptive cruise control is one of those features where once you experience it, you never want to go back.
Older cruise control, which cars have had for decades, is straightforward: Push a button and the vehicle maintains its set speed. The driver can then take their foot off the gas, which is relaxing on long drives when there are few other cars on the road.
But that’s rarely the case in busy urban areas, where the need to brake frequently cancels out the function and limits its usefulness. Enter adaptive cruise control.
What is it?
Adaptive cruise control lets the driver set a travelling speed and automatically maintain a constant distance from the car ahead. When the car ahead gets closer, your car slows down on its own. When the car ahead speeds up, so do you.
It’s an early step toward autonomous driving in which the car controls its own speed and distance from other vehicles.
How does it work?
Adaptive cruise control systems rely on radar sensors built into the front of the car. The radar continually tracks vehicles ahead as the car’s computer calculates and maintains distance by applying acceleration or brake. It’s like a robot working the pedals on the driver’s behalf.
Many manufacturers also incorporate cameras into their systems to help distinguish vehicles from other objects.
“That’s what it’s concentrating on,” says Terry Tizzard, manager of Hyundai Performance Academy for Hyundai Canada. “It won’t pace you off a bicycle on the side of the road.”
Earlier adaptive systems could bring the car down to about 30 kilometres an hour before disengaging and reverting to manual control. Newer systems continue to work even down to a full stop. They generally disengage after three seconds of stoppage, at which point the driver has to manually re-engage the system by stepping on the gas.
As with regular cruise control, adaptive versions are activated with the same set of buttons on the steering wheel. One button turns the system on while a small lever sets the speed.
Adaptive cruise control adds a further button for selecting how closely to follow the vehicle ahead, with three settings: close, medium and far. At a speed of 100 kilometres an hour, the following distances are generally 30, 45 and 60 metres, respectively. The distances are shorter at slower speeds and longer when going faster.
What is it for?
Although adaptive cruise control has all of the makings of an autonomous driving feature, auto makers are marketing it as a convenience.
“If you’re caught in heavy traffic, it’s a benefit because you’re not constantly braking and slowing down,” says Scott Pak, senior product planning manager for Nissan North America. “The system is doing it for you.”
Manufacturers are quick to point out that adaptive cruise control isn’t a safety feature. One area in which it can prove tricky is when another vehicle suddenly cuts you off by unexpectedly moving into your lane, which can cause your car to brake hard.
“That’s to make sure the driver is still paying attention. We designed it into the system to make sure the customer is still looking at the road,” says Scott Lindstrom, driver assist technologies manager at Ford.
“We’re tuning the system to react, but we also don’t want it to overreact. They are systems where drivers have to stay aware and pay attention.”
Adaptive cruise control generally isn’t standard yet, but many auto makers are offering it as an option. Newer Hyundai cars including the 2019 Santa Fe and Sonata, for example, will have the more advanced stop-and-go capability, as do most core Nissan and Infiniti vehicles starting with model year 2018.
Ford says its 2018 F-150 and Expedition have the function, as do the 2019 Fusion and Edge.
Toyota, meanwhile, is offering it in many Lexus models and in Camry, Prius, Sequoia, Tacoma and Tundra, among others.
What are the rules?
Since adaptive cruise control is a convenience rather than a safety feature, there aren’t yet any regulations around its use aside from requirements that self-braking cars also automatically engage their rear brake lights.
“This is not a safety system and should never be used as a collision-prevention system, but it really makes highway driving easier,” says Hideki Hada, executive engineer in the research and development division of Toyota Motor North America. “That’s the goal.”