In my last Brightmile article, I wrote about why autonomous vehicles have been slow to arrive. I also suggested we pay more attention to the advanced driver-assistance systems (ADAS) available now. This tech is incredibly powerful, and how we use it—or ignore it—can be lifesaving or lethal.
The range of ADAS is vast, so I’ll cover only three common types here: adaptive cruise control, emergency automatic braking, and lane-keeping assist/lane departure warning.
What Is ADAS and How Does It Work?
ADAS is a collective term for different electronic, vehicle-based, intelligent systems that help human drivers avoid crashing or mitigate collisions. Most ADAS is safety-related, but some provide convenience (like parking assistance).
To build a picture of and monitor its environment, ADAS uses interior and exterior cameras, ultrasonic sensors, radar transmitters, highly advanced software and computer processors, and satellite-mapping technology.
Adaptive Cruise Control (ACC)
Pros: We’re all familiar with regular cruise control, but adaptive cruise control takes it a step further by letting you set a maximum speed and a specific distance behind the vehicle ahead. Your vehicle automatically speeds up, slows down, and brakes while keeping your preset following distance. Thus, ACC helps prevent rear-end collisions, reduces crash severity, decreases tailgating, and lowers stress in congested traffic.
Cons: Drivers often don’t realize that ACC can be set to a following distance that’s too close. Three seconds is the minimum safe distance on dry pavement and six seconds on rainy days; some ACC allows you to follow as closely as 1.3 seconds. Just because your vehicle allows you to maintain a certain distance doesn’t mean it can always stop in that space.
The degree of ACC’s braking is also limited by vehicle speed, environmental conditions, and automaker specs. Some vehicles can come to a complete stop while others won’t, so understanding your specific car’s limitations is crucial. And just because ACC is operating doesn’t mean you can take your eyes off the road or text on your smartphone. It may not function properly in fog or rain or on slippery surfaces, curvy roads, or tunnels, so you still need to stay alert and be ready to intervene at a moment’s notice.
Emergency Automatic Braking (EAB)
Pros: By sensing slow or stopped traffic ahead, automatic emergency braking can slam on the brakes if you don’t respond. It can be lifesaving in unpredictable situations, like when a child runs into the road, a vehicle ahead stops faster than you can react, or you fall asleep behind the wheel. Although EAB can’t always fully stop your vehicle in time to prevent a collision, it will scrub off speed, which may prevent serious injury and death.
Cons: Some drivers believe that EAB safeguards them, given how it appears to function. But many don’t know that it works best when objects or vehicles in front are fully stopped—not so much when they’re moving. It’s also more reliable at highway speeds when the sensors detect greater contrasts in the relative speed of what they’re closing in on. And extremely bright or very low lighting can trick sensors into not “seeing” objects as large as trucks.
EAB sometimes activates without an apparent cause, frightening drivers. These false positives are caused by road conditions, weather, very uneven road surfaces, acute angles, or sharp curves. A sensor might momentarily misregister a benign object in the road as something to avoid, like the large steel plates used in road construction.
Once again, EAB is no substitute for paying attention!
Lane-Departure Warning and Lane-Keeping Assist
Pros: These two ADAS function separately, but they work together to literally keep you on the road. Lane-departure warning uses lights, sounds, and vibrations to alert the driver that the vehicle is about to leave its current lane, while lane-keeping assist uses the road’s painted lines to steer the vehicle back into the lane or away from the shoulder. Leaving a lane due to inattention or drowsiness is one of the most frequent causes of serious injury and death, often happening in less than a second, so these ADAS are exceptionally lifesaving.
Cons: These ADAS work only when they detect reliable lane markings. If these are worn off, absent, or obscured by leaves, snow, ice, or debris, you’ll need to take over the driving task manually.
The Myth of AutoPilot and FSD
One of the most confusing—and dangerous—aspects of ADAS is that automakers often market them in ways that encourage drivers to believe they can “set it and forget it” when just the opposite is true. Tesla is the worst offender with its egregiously named AutoPilot and FSD (Full Self-Driving) features, which mislead consumers—sometimes fatally—to think its cars can drive themselves. As of June 2023, no true self-driving car is available that the general public can buy and own—don’t let the marketing hype and owner testimonials fool you.
Is It Really Worth It?
From this article, you might wonder if ADAS is really worth it. The answer is a resounding yes. Safety studies of ADAS-equipped vehicles have shown actual and projected drops in certain crashes by 24 to 78 percent, especially those involving backing up, rear-ending, and lane departure. This trend will surely continue as these vehicles become more common on our roadways, saving thousands of lives annually.
But we need to consider these amazing systems only as backup safety nets, not foolproof tech that we can get complacent about using.
For more ADAS information, an excellent resource is My Car Does What, which clearly defines each feature, how it works, and its benefits and limitations. And don’t forget to read your owner’s manual—it’s the ultimate guide to the ADAS specific to your vehicle.
