How safe is your vehicle?

Increasing the number of safety devices in vehicles, making structural changes, and testing these innovations have helped reduce deaths and injuries on U.S. roads. But while these features help protect a vehicle’s occupants during or following a collision, they do not prevent or mitigate the severity of collisions.

Other recent safety features act as more preventative measures. These vehicle features, which are becoming increasingly available, include:

  • Head-up displays that project data such as speed, distance from the car ahead, etc., in front of drivers at eye level, so they don’t have to glance away from the road.
  • LED headlights that illuminate farther down the road than halogen or HID headlights.
  • Adaptive headlights that follow a curve as a car turns, allowing better visibility.
  • Self-dimming rear-view mirrors that prevent glare, allowing drivers to better judge how close they are to other cars and to pass or change lanes more safely.
  • Automatic high/low beams that detect headlights or taillights of vehicles ahead and automatically switch between high beams and low beams to improve a driver’s visibility.
  • Driver-alert systems that monitor driver behavior, such as eye and head movements, that might indicate a driver isn’t fully alert. If the system senses a potential problem, it issues a visual and/or audible alert.

Advanced driver-assist systems

In recent years, safety technology has taken a more active role. Many vehicles now include features that help prevent collisions or reduce their severity. These electronic systems are known collectively as advanced driver-assist systems (ADAS); they started out as optional equipment but are becoming standard equipment on more cars.

ADAS act as a safety net; for example, blind-spot monitoring alerts drivers to cars they might not be able to see in adjacent lanes. In other cases, ADAS reduce the effects of mistakes drivers have already made—such as drifting out of their lane or getting too close to the vehicle in front of them—by taking temporary control of the vehicle.

The National Highway Traffic Safety Administration estimates that more than 90 percent of vehicle crashes involve human error. ADAS have the potential to improve driving safety, as they can help mitigate driver errors. And because they take over various driving functions, they’re also foundational to the development of self-driving or autonomous vehicles.

ADAS appeared first on high-end vehicles, then eventually became available in midpriced and lower-priced vehicles. Many safety features are now available on almost every model in various manufacturers’ lineups. For example, the Toyota Yaris iA, which has a base price under $18,000, comes with a low-speed collision-avoidance system as standard equipment. Blind-spot monitoring with rear cross-traffic alert is available on a 2017 Mazda Mazda3 for less than $23,000, and blind-spot monitoring with rear cross-traffic alert plus Subaru’s well-regarded EyeSight collision-avoidance system are available on a 2017 Impreza costing about $24,000.

If recent history is an indicator of upcoming trends, advanced driver-assist systems will become more widespread and will be standard equipment on more vehicles. In 2016, a blind-spot monitoring system with cross-traffic alert was optional on the high-end Ford Escape Titanium but unavailable on lower trim levels. The following year, that feature became standard on the Titanium trim level and optional on the mid-level SE.

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.

Rearview camera

This safety feature will be required equipment on all new cars sold in the U.S. as of May 2018. One 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 three.

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 one 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 two 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 five 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.

Limitations of ADAS

Good driver-assist systems have controls, displays, and touch screens that are easy to understand and operate. As a fail-safe measure, many systems won’t activate until drivers go through two or more steps and are fully aware when the systems are operating.

However, as with other electronic systems, ADAS don’t work 100 percent of the time. For example, they might not detect other vehicles or lane markers in bad weather (snow, rain, or fog); they might not detect faded lane markers or small objects in the road; and they work better on multi-lane highways than on narrow country roads. Some systems turn themselves off if they can’t “see” what they need to, and many ADAS can be switched off if drivers don’t want to use them.

Also, it’s critical to understand what any driver-assistance system is designed to do—and not do—before you leave the dealership. For example, ACC systems may keep your vehicle a safe distance from a moving car in front of it, even when that car comes to a complete stop. But some systems aren’t designed to recognize stationary objects, including cars. That means these particular systems might not prevent you from hitting a stopped car.

In short, drivers must be responsible for maintaining control of their vehicles. While ADAS provide added safety and convenience, it’s important not to rely on them. After all, they’re mean to be a support system, not a substitute for safe, alert driving.