a graphic photo of a vehicle collision avoidance system in action

What are collision avoidance systems?

Distracted driving accidents are some of the deadliest types of motor vehicle accidents, claiming more than 3,500 lives in 2021 in the United States alone. While many of these car accidents could be easily prevented by paying close attention to the road, you can never be sure that drivers around you won’t be distracted or texting and driving. That’s why vehicle manufacturers have developed collision avoidance systems to reduce distracted driving accidents. 

What Are Collision Avoidance Systems?

A collision avoidance system (CAS) is designed to help a motor vehicle’s driver avoid a crash and improve highway safety. Also known as crash avoidance systems, these systems could either notify the driver of a potential hazard through an alarm or take direct action by steering the vehicle or deploying the emergency brakes.  

How Do Collision Avoidance Systems Work?

A CAS uses radars, lasers, cameras, algorithms, and more to identify potential crash risks. They then deploy a crash warning to alert the driver of potential warnings through visual, auditory, or haptic means. These systems help prevent common motor vehicle accidents like blind spot accidentsguardrail accidents, and more. 

Most cars are equipped with front-facing and rear-facing sensors that alert the driver of the proximity of an object. You might hear these beeps, for example, if you are parking and start getting too close to the car in front of you. This can help prevent front-end collisions and rear-end collisions by alerting the driver before it’s too late.

A more advanced CAS may include artificial intelligence (AI) technology to prevent crashes with other cars on the road actively. They often use a combination of dash cameras, GPS maps, and machine learning to avoid potential collisions. Cars equipped with self-driving technology, like the Tesla autopilot, usually come with this technology.

What Are the Different Types of Collision Avoidance Systems?

Some of the most common types of CAS are:

  • Forward collision warning system (FCW). These systems monitor the vehicle’s speeds equipped with the technology and the speed and distance of the vehicles around it. It will alert the driver if a sudden change in speed could result in an accident.
  • Lane departure warning system. These systems monitor the vehicle’s position in relation to the lane it’s driving on. It will alert the driver if the vehicle inadvertently drifts from the lane.
  • Pedestrian detection system. These systems monitor any pedestrians on or near the road and alert the driver, including cyclists and jaywalkers if they are getting too close to the vehicle. These systems help prevent pedestrian accidents.
  • Blind spot warning (BSW). These systems notify the driver when a vehicle is coming up on adjacent lanes. These systems can be especially helpful when switching lanes, as drivers may easily overlook a car in the blind spot. 
  • Automatic braking system. This technology automatically triggers the vehicle’s braking system when it senses another object rapidly approaching. Some automatic braking systems will deploy a complete stop, while others simply slow the vehicle down to allow the driver to react.
  • Parking sensors. They help detect small objects near the vehicle to assist with parking. They can help drivers avoid hitting other vehicles, trees, poles, fences, etc.
  • Curve adaptive headlights. Headlights posted according to steering help improve visibility when driving on curves. 

Do Collision Avoidance Systems Prevent Accidents?

Plenty of evidence supports the claim that collision avoidance systems help prevent accidents. In particular, forward collision warning systems combined with autonomous emergency braking systems were extremely effective at reducing the rate of front-to-rear collisions.

A study by the Insurance Institute for Highway Safety, a non-profit highway safety organization, found that combining these two types of CAS could reduce the rate of rear-end striking accidents by up to 50% and up to 56% in the case of rear-end striking accidents with injuries. The study also estimates that almost 1 million police-reported rear-end crashes could be avoided in the U.S. in a year if all vehicles were equipped with these types of CAS.

Can Collision Avoidance Systems Cause Accidents?

No technology comes without fail, and collision avoidance systems are no exception. Although they are typically solid aids for drivers, they may occasionally cause an accident due to the following:

  • Overreliance by the driver. Relying too heavily on a CAS may cause the driver to delay or omit a maneuver to avoid a crash. 
  • Misunderstanding CAS technology. Drivers may expect their CAS to detect every vehicle and pedestrian on the road, while many vehicles only have blind-spot monitoring. 
  • Weather interference. Weather and environmental factors like rain, sleet, snow, or fog could affect CAS performance. 
  • Malfunctions. All technology malfunctions from time to time. A CAS malfunction could cause the vehicle to come to a sudden stop when there is no imminent threat or to avoid stopping when approaching an object.
  • Self-driving features are still faulty. Autopilot or assisted driving technology is still new, so drivers should exercise caution when deploying it. 
  • Inadvertent deactivation. Most new vehicles come with optional CAS technology, which may be deactivated accidentally or independently.

What Can I Do if My Vehicle’s Collision Avoidance System Causes a Crash?

In most cases, a driver is still responsible for any accidents or injuries caused by their vehicle, even if a CAS was involved. However, the driver may be able to hold the car manufacturer responsible for a crash if it resulted from a major fault in one of the car’s collision avoidance systems. For this to happen, however, the CAS needs to be the primary cause of the accident.

If you were involved in a motor vehicle accident and believe your car’s CAS is to blame, then you should contact an attorney to discuss your options. You may be able to hold the auto manufacturers responsible if the CAS caused you to get into an accident.


Morris & Dewett provides this information to the public for general education and interest. The firm does not represent clients in every topic discussed in legal & injury news. The information is curated and produced based on trends in law, governance, and society to present relevant issues to the general public. Every effort is made to provide accurate information. Do not make any decision solely based on the information provided, please seek relevant counsel for each topic area. Consult an attorney before making any legal decision, consult a doctor before making any medical decision, and consult a financial advisor before making any fiscal decision. If you have any legal needs that we can assist you with, please do not hesitate to contact us.

Morris & Dewett Will Answer Your Questions and Help You Recover