Types of ADAS
The following advanced driver-assist systems are either standard equipment or can be ordered on many new cars. Note that individual automakers’ systems will vary and may use different nomenclature.
This safety feature will be required equipment on all new cars sold in the U.S. as of May 2018. A recent variation worth noting is a 360-degree view of what’s happening around a vehicle. Vehicles offering the 360-degree view include the Ford F-150 and Mercedes-Benz GLC300.
Blind-spot monitoring/rear cross-trafﬁc alert
Blind-spot monitoring (BSM) uses radar technology in a car’s rear quarter panels to detect cars that are immediately beside and behind your vehicle. The system alerts you if you start to make an unsafe lane change that could result in a collision with another car. When a car is in your blind spot, a small icon lights up, typically in your car’s side mirror. If you activate a turn signal while a vehicle is in your blind spot, the light flashes, and sometimes a warning tone also sounds. Some BSM systems use cameras to show what’s going on in the driver’s blind spots. With Honda’s LaneWatch, when you activate the right-turn signal, the touch screen on the dashboard shows what’s happening on the right side of your car.
Blind-spot monitoring and rearview-camera systems are often paired with a rear cross-traffic alert (RCTA) function, which is useful when you’re backing out of a head-in parking spot. When you’re backing up, the system typically flashes a warning signal in the side mirror, A-pillar, or the rearview-camera display on the touch-screen display and sounds a warning if a vehicle is approaching from the left or right.
Lane-departure warning/lane-keeping assist
Lane-departure warning (LDW) and lane-keeping–assist (LKA) systems typically use cameras or sensors mounted on the windshield near the rearview mirror to read road markings and help you stay in your lane. If your vehicle starts to drift out of its lane, LDW alerts you with a sound, a flashing icon on the instrument panel, pulsing or vibration in the steering wheel or driver’s seat, or a combination of all 3.
LKA systems go even further: When you start to drift out of your lane, the system nudges the steering wheel or selectively brakes a single wheel to guide the car back into the lane. Such corrections are subtle, and you can always override them by turning the wheel yourself.
Note that LDW and LKA systems don’t function when you use your turn signal. If you have an LKA system on your vehicle, you can’t just take your hands off the wheel and expect the car to do the steering for you. On some vehicles, if the car doesn’t sense steering input for a brief period (about 10 seconds), it alerts the driver to regrip the wheel.
Forward-collision warning/automatic emergency braking
Several types of forward-collision systems use cameras and/or radar to help drivers respond safely to traffic in front of them. The following is a general description of the different types of systems. Automakers may use 1 or a combination of such systems in their lineups.
- A forward-collision warning (FCW) system provides audible and visual alerts that warn drivers of a potential crash, but it does not apply the brakes to prevent a crash from occurring. There are also 2 types of automatic emergency braking (AEB) systems. The difference between such systems is mostly one of degree:
- A forward-collision mitigation (FCM) system lets drivers know a collision is imminent and, if the driver doesn’t respond, applies the brakes to attempt to minimize the damage.
- A forward-collision avoidance (FCA) system alerts drivers to the likelihood of a crash and automatically applies the vehicle’s brakes to either prevent a crash or reduce the severity of the impact. It also may retract and increase the tension of the occupants’ seatbelts.
As of September 1, 2022, virtually all new cars will feature AEB systems like those described above. In 2016, AAA tested 5 different vehicles equipped with AEB. In all cases, the AEB systems worked, but there was considerable variation in performance among different systems. If you buy a vehicle with AEB, it’s really important that you understand how the braking system functions, as not all systems are created equal.