Rear-end collision avoidance systems are meant to help drivers avoid being involved in rear-end crashes. These types of systems rely on radar and cameras to detect when a motorist is driving too fast and assist the vehicle with decelerating on time to avoid colliding into the back of vehicles in front. While rear-end collision systems are becoming more common in vehicles, they also have some limitations about which you should be aware. Regardless of technological advances, motorists should not be overly reliant on them and should remain focused on the road so that they are prepared to react in time and avoid crashes and legal liability for rear-end collisions.
Understanding rear-end collisions
Rear-end crashes are the most common types of collisions that happen in the U.S. Each year, an average of 1.7 million rear-end accidents are reported. While many of these wrecks result in property damage only, many others cause catastrophic injuries or fatalities. An estimated 500,000 people are injured in rear-end accidents each year, and another 1,700 are killed.
Most rear-end crashes are preventable. Many are caused by negligent driving behaviors, including texting while driving, talking on the phone while driving, inattentive driving, drowsy driving, speeding, and others. Rear-end collision technology is a type of safety technology that aims to reduce the prevalence of these types of accidents by alerting drivers and applying brakes automatically.
While rear-end collision avoidance technology might help to prevent accidents, there are a few limitations to it that drivers should understand. People should never overly rely on technology and should instead keep their attention focused on the roads at all times when they are behind the wheels of their vehicles.
What is rear-end collision technology?
Rear-end collision avoidance systems are designed to detect the speed of the vehicles in which they are installed and the vehicles or objects in front of them. These systems rely on cameras and radar to communicate information about hazards to the drivers. A rear-end collision avoidance system might include several features, including automatic braking systems to brake when the motorist fails to do so on time, adaptive headlights to turn in the direction the driver steers, pedestrian detection systems to detect the presence of pedestrians, rearview cameras, and rear braking systems to prevent motorists from backing into people or vehicles located behind their vehicles.
In 2018, the Insurance Institute for Highway Safety conducted a study in which they found that vehicles that had rear-crash collision avoidance systems installed were 78% less likely to be involved in rear crashes while backing up. These types of systems can help to prevent low-speed crashes in parking lots and tragic accidents involving people backing into children or other pedestrians when they exit driveways.
Rear-end collision technology, by contrast, is a forward-collision avoidance system. It is designed to prevent the vehicle in which it is installed from colliding into a vehicle it is following or into other objects that might be in the vehicle’s path on the road. These systems might engage the vehicle’s automatic emergency braking system to cause the vehicle to quickly decelerate to avoid crashing into the back of the vehicle or object in its path.
Forward-collision avoidance technology shows promise in helping to prevent accidents. As more semi-autonomous vehicles enter the market and appear on the highways, people are likely to increasingly rely on this type of technology to help them avoid being involved in collisions. While all types of safety technology hold promise for a reduction in accidents, injuries, and fatalities, rear-end collision avoidance systems have limits. For this reason, people should never rely only on the technology installed in their vehicles and should instead keep their focus on the road whenever they get behind the wheel. A few of the limitations of rear-end collision technology are discussed below.
Algorithms are not infallible
Rear-end collision avoidance systems are not infallible. They rely on algorithms that are programmed in by people. Programming mistakes can introduce errors into these systems and prevent them from working properly.
One 2017 crash investigated by the National Transportation Safety Board illustrates some of the limitations posed by the software used by semi-autonomic vehicles to avoid collisions. The crash involved a 38-year-old man who was driving a Tesla SUV in California while using the vehicle’s adaptive cruise control and lane-keeping systems.
The driver was reportedly distracted by a video game on his cell phone at the time while he was traveling in the HOV lane. While he was distracted, the vehicle’s autopilot system steered the vehicle into a gore area of the highway. Since the adaptive cruise control was engaged, the vehicle sped up. The system failed to detect that the vehicle was in a gore area and that a crash attenuator was in the path of the vehicle to mark the end of a concrete median. The SUV crashed into the attenuator and then into two other vehicles before bursting into flames.
The NTSB identified several issues that contributed to the crash. The first thing that the agency noted is that the man was distracted and not focused on the road while the autopilot was engaged. If he had not been distracted, he would have likely noticed that the vehicle was headed towards a gore area and had been able to safely steer it back into the lane of travel.
The NTSB noted that the collision avoidance system in the vehicle failed to detect the crash attenuator and to apply the automatic emergency braking system. Instead, the vehicle accelerated and did not send alerts to the motorist. The NTSB also noted that the autopilot system did not include any type of technology to detect the attentiveness of the motorist while he was behind the wheel. The failure of the system to detect the crash attenuator was believed to be due to a processing error in the software itself.
Weather and lighting can affect collision avoidance systems
Another limitation of rear-end collision avoidance technology is that inclement weather can interfere with its proper functioning. When you are driving through snow, fog, or rain, your forward collisions warning system might not detect vehicles traveling in front of you on the road. The cameras might not be able to “see” vehicles that are present and obscured by the weather. During a storm, the sensors might also be covered by ice or snow and stop functioning altogether. It is best to avoid using your automatic emergency braking and collision avoidance systems when you drive in inclement weather.
Another issue can occur when there is a glare or in low-light conditions. This is especially problematic for vehicles with systems that rely on lasers and cameras. For example, when you travel through a tunnel, your system might struggle to detect vehicles in front of you and might also have problems when your vehicle emerges from the dark conditions inside of the tunnel into the glare of the sun. This makes it important to be extra cautious while driving in these types of conditions and to carefully scan the road to react in time to avoid a rear-end collision.
Sudden, unexpected braking and other malfunctions
Millions of people rely on automatic emergency braking systems in their vehicles to help them to stop their vehicles on time to avoid colliding with vehicles and objects in front of them. However, there have been hundreds of complaints filed about defects in automatic emergency braking systems that have caused vehicles to suddenly brake when there was no risk of an accident.
According to a report in the Wall Street Journal, more than 400 complaints were filed with the National Highway Traffic Safety Administration about malfunctioning emergency braking systems between 2016 and 2019. Many of the complaints were about braking systems that suddenly engaged when no danger was present, and in some cases, this sudden braking occurred without warning while the motorists were traveling at highway speeds. Other motorists reported that their automatic emergency braking systems failed to engage at all when a hazard was present.
In 14 of the complaints, the malfunctioning AEB systems caused collisions. In several of the crashes, the malfunctioning brakes caused the vehicles to stop so suddenly that vehicles behind them couldn’t avoid crashing into their rears. Three of those crashes resulted in injuries.
Other people reported that their AEB systems engaged and stopped their vehicles while they were crossing over railroad tracks. Some people also reported losing control of their vehicles because of the sudden braking and crashing into guardrails.
While rear-end collision avoidance technology promises to help reduce the number of rear-end crashes, people should not solely rely on it. Instead, all motorists should ensure that they keep their attention focused solely on the roads while they are driving. Drivers should be prepared to react and not wait for their safety technology to act for them. When the weather conditions are poor, motorists should consider turning off their collision avoidance and automatic emergency braking systems to avoid otherwise preventable accidents.