How Can Cars Avoid a Crash?

The term "crash avoidance" can encompass a wide variety of vehicle features designed to help the driver operate the vehicle safely. Vehicles increasingly offer various advanced systems that assist the driver with warnings or automatic braking to avoid or mitigate a crash. In this section, explore how IIHS researchers test and evaluate these systems. Also, discover how crash avoidance systems monitor the environment around the vehicle and warn the driver when they detect the possibility of dangerous conditions.

Crash avoidance systems can help prevent collisions that could result from a variety of dangerous conditions. In many cases, drivers can be warned if a collision is imminent, or the system can automatically slow or stop the vehicle. Adaptive headlights can pivot into optimal direction, while adaptive cruise control can monitor both vehicle speed and the distance to the vehicle ahead. Researchers at the IIHS Vehicle Research Center continue to create and update testing for these systems.

This knowledge can lead to the overall improvement of crash avoidance systems and fewer crashes and injuries on our roadways.

Front Crash Prevention

Front crash prevention systems alert the driver when the vehicle is getting too close to one in front of it. Most systems precharge the brakes to maximize their effect if the driver responds to the warning. Some systems are able to brake the vehicle autonomously if the driver doesn't respond. These systems use various types of sensors, such as cameras, radar or light detection and ranging (LIDAR) to detect vehicles in front of the vehicle. A forward collision warning system with autonomous braking may not always be able to prevent a crash but may reduce vehicle speed, mitigating the severity of the crash.

Lane Departure and Warning

Lane departure warning and prevention systems use cameras to track the vehicle's position within the lane, alerting the driver if the vehicle is in danger of inadvertently straying across lane markings. Some systems use haptic warnings, such as steering wheel or seat vibration, while others use audible and/or visual warnings. Some systems cause the vehicle to actively resist moving out of the lane or help direct the vehicle back into the lane through light braking or minor steering adjustments

Blind Spot Detection

Technology that helps drivers keep an eye on their blind spots cuts crashes in the real world. Read about IIHS blind spot detection research here: go.iihs.org/blindspot

Park Assist and Backover Prevention

Park assist and backover prevention systems help drivers park and back up. Rear object detection systems use cameras and sensors to help the driver look for objects behind the vehicle when backing up. Rearview cameras display what is behind the vehicle, and radar or ultrasonic systems warn the driver of objects behind the vehicle. Some systems will even automatically apply the brakes to keep the vehicle from backing into or over an object. A cross-traffic alert system uses sensors to detect approaching vehicles that may cross the path of a vehicle backing up, warns the driver of their presence, and may automatically apply the brakes to prevent a collision. Some parking assist systems also are capable of automatically parallel parking the vehicle.

Adaptive Headlights

Adaptive headlights help drivers see better on dark, curved roads. The headlights pivot in the direction of travel based on steering wheel movement and sometimes the vehicle's speed to illuminate the road ahead.More information at Headlights.

Adaptive Cruise Control

A related feature to forward collision avoidance is adaptive cruise control, which is typically marketed as a convenience feature. As with regular cruise control, the driver sets the desired speed. The difference is that the vehicle automatically slows down in heavy traffic in order to maintain a safe gap without the driver having to do anything. Forward-mounted sensors track the distance to a lead vehicle, and the engine and brakes are used to maintain a safe gap if traffic slows. As traffic speeds up, the vehicle accelerates to maintain the preset cruise speed. Some systems allow drivers to adjust this gap, resulting in smaller or larger following distances. If the vehicle slows below a certain speed as it approaches another vehicle, some systems are designed to disengage and require the driver to resume control, while others can bring the vehicle to a complete stop.

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