ADAS: Advanced Driver Assistance Systems

When I make vehicle recommendations for a client, I try to select vehicles that have as many advanced driver assistance systems (ADAS) as their budget allows.

ADAS ≠ Autonomous

When ADAS first emerged about ten years ago, I was not on board. As someone who loves to drive, I thought these new technologies were ushering in the era of the self-driving car. But, I misunderstood what these systems actually were. Nowadays, some technologies do blur the lines between ADAS and true autonomous driving, like Tesla’s AutoPilot or Cadillac’s Super Cruise. But generally ADAS technologies are quite different than self-driving capabilities.

Of course, the very best safety feature is an attentive driver. These systems don’t exist to take over the function of driving from the driver. Instead, they supplement the driver with a technological safety net. They help to reinforce the observations of an already alert driver. They can also fill in the gaps in human reaction time to respond to obstacles more quickly.

ADAS technologies are effective

In fact, the largest cause of accidents is driver error, including the failure to properly recognize hazards, according to the National Highway Traffic Safety Administration. ADAS are proven to reduce both accidents and insurance claims by allowing your vehicle to react to dangers faster than a human can. For the data to back this up, click this link.

Advanced driver assistance systems are becoming more commonly standard on many new models. But they remain an option on many vehicles (and on some dated automotive designs, including several that I name in this blog post as the five 2020 models to avoid, they’re not available at all). I expect these systems to become mandated by the government eventually, just like seatbelts, airbags, and backup cameras, due to their proven effectiveness. But in the meantime, make sure your next vehicle has these potentially life-saving technologies.

ADAS alphabet soup time!

But, exactly what are these systems, and what do they do? I’m glad you asked! The following are the most common ADAS technologies available today, and how they operate.

Of note, different automakers use different names to refer to similar systems. There is a push to adopt uniform terminology for ADAS for clarity, and I will follow the proposed standard below.

Forward Collision Warning (FCW)

This system uses sensors to scan the road in front of your car. If it detects an obstacle in the path of your vehicle, and you have not reacted, the car will flash a visual warning and/or sound an alert.

FCW was one of the first types of ADAS. On new cars today, it is commonly paired with the following system as well.

Automatic Emergency Braking (AEB)

Layering on top of FCW, many cars also feature AEB. After FCW activates, AEB can apply the brakes for you, if you don’t respond in time. Depending on the car’s system and your speed of travel, AEB may bring your car to a complete stop, avoiding the accident all together. Or, if you’re driving at a speed that makes an accident unavoidable, AEB will at least slow your car down and minimize the severity of the accident.

Depending on the manufacturer, some AEB systems only operate at city driving speeds. Some work at both city and highway speeds.

Many FCW with AEB systems now also include pedestrian detection, and some can detect bicyclists as well.

Lane Departure Warning (LDW)

LDW uses sensors to scan the lane marker lines in the road. If your car crosses a line, but you haven’t used your turn signal to indicate an intentional lane change, the system will alert you. Some systems use an audible warning, and some create a small vibration in the steering wheel. LDW is intended to prevent you from sideswiping a car in an adjacent lane on the highway, from crossing the center line and causing a head-on collision with oncoming traffic, and from veering off the road onto the shoulder or into a ditch.

LDW systems usually only operate over a certain speed. So, your car won’t beep or buzz at you as you drive through a parking lot, or slow down to make a turn.

Lane Keeping Assistance (LKA)

This system expands upon LDW technology, and can make small steering corrections for you. If your car senses that you’re leaving your lane of travel, and no turn signal has been used, LKA can slightly steer you away from the lane marker and away from other traffic. It can be unnerving and unnatural the first few times you feel your steering wheel move in your hand without your input, but LKA is a great feature.

Cars with LKA have an indicator in the instrument panel so that it’s clear when LKA is operating, and when it isn’t. LKA also only operates above a certain travel speed. It may not operate in bad weather, or on roads with faded or poor lane markers.

Some LKA systems also include lane centering. Vehicles so equipped can watch the lane markers and make subtle steering motions to keep your car driving approximately in the center of your lane.

Blind Spot Warning (BSW)

Of all ADAS, BSW has been around the longest in mainstream vehicles. BSW uses sensors to scan your car’s blind spots. Most turn on an indicator somewhere in or near your side mirrors to let you know when a vehicle is in your blind spot. In most systems, if you then use your turn signal while a car is in your blind spot, an audible alert will sound.

Rear Cross Traffic Alert (RCTA)

RCTA is typically packaged with BSW. When your car is in reverse, RCTA scans both sides of your vehicle watching for oncoming traffic. If traffic is approaching, an alert will sound. As a driver of a sedan, when I’m sandwiched in between two SUVs in a parking lot, I always wish my car had this feature. RCTA systems can scan for potential hazards beyond what can be seen using your car’s backup camera.

On some vehicles, beyond sounding an alert, RCTA systems can also apply the brakes for you, stopping you from reversing into the path of an oncoming vehicle.

Adaptive Cruise Control (ACC)

On many cars with ADAS, ACC is often included as well. While it has some safety benefits, it is a godsend on longer trips. I view it as a convenience feature as well, by greatly minimizing driver fatigue.

ACC works like traditional cruise control systems in that you set your car to maintain a predetermined speed. It also watches the traffic ahead of you, and will slow your car down if there’s someone in front of you driving at a slower speed. ACC systems can maintain a range of following distances between your car and the vehicle in front of you. If that vehicle speeds up, or if you change lanes and there’s no traffic ahead of you, your car will accelerate back to your set cruising speed.

Some ACC systems are also designed to operate in stop-and-go traffic. This can minimize the hassle of crawling along in a traffic jam.

In Conclusion…

To reiterate, none of these systems can replace the safety benefits of a skilled and attentive driver. But when you view ADAS as a backup failsafe, they can keep you, your passengers, other drivers, their passengers, and even pedestrians and bicyclists safer. As ADAS technologies continue to be proven to reduce accident and injury rates, they are likely to become standard on all cars in the future. Until then, make sure your next car has these critical safety features.