Automatic emergency braking will be standard in most cars in 2022. The technology is expected to cut the number of rear-end crashes in half, but hundreds of drivers say sometimes the system slams on the brakes – apparently for no reason.

CBS News found reports of several accidents and injuries that drivers blamed on false activations of emergency automatic braking systems. Safety advocates and carmakers say in the vast majority of cases it works, but it is not perfect.

For Cindy Walsh, getting behind the wheel of her 2018 Nissan Rogue raises her anxiety level. Since she bought the SUV new last October, she told CBS News correspondent Kris Van Cleave it has slammed on the brakes three times for no clear reason when she said there was no risk of a collision.

"The first one, I was driving down a four-lane highway going about 55 and it completely came to a complete stop," Walsh said. Now she said she's scared to drive the car, so she doesn't drive it.

Walsh took it to the dealer each time. Twice, she said, they told her they fixed it.

The National Highway Traffic Safety Administration (NHTSA) is now investigating the 2017 and 2018 Rogue after learning of nearly 850 complaints of false activation of the SUV's automatic braking system. That includes reports of 14 crashes and five injuries.

The Rogue, like about half of new cars sold, is equipped with forward collision avoidance technology that includes automatic emergency braking. It's supposed to sound an alarm and automatically brake if you are about to rear-end another vehicle. It will be standard in most cars within three years.

"People [were] saying they were turning it off… The technology can help and does save you and prevents crashes, but only if it's on and only if it's working," said Jason Levine of the Center for Auto Safety. "We want to see this move towards a recall very quickly."

The Insurance Institute for Highway Safety (IIHS) said autobraking is making driving safer, estimating the technology could cut rear end collisions in half, preventing 28,000 crashes and 12,000 injuries by 2025.



"These autonomous emergency braking systems, they are effective. They are working in the real world. But there is definitely room for improvement," said David Aylor, IIHS' manager of active safety testing.

Since 2015 there have been seven recalls for auto-braking issues, affecting nearly 180,000 vehicles. There are more than half a million Nissan Rogues subject to the NHTSA investigation. The regulator has also received hundreds of complaints about so-called "phantom braking" in vehicles from a number of automakers.

"It happened to us last year. We were driving a Tesla Model 3 with autopilot," CNET Roadshow editor Tim Stevens said. "The car pumped the brakes as we approached an overpass on a busy New Jersey freeway."

"It may have actually seen that bridge as another car," he added, "And so another example that autopilot is not perfect."

In a statement Nissan acknowledged some Rogue drivers may experience "false activation," saying: "Nissan is committed to the safety and security of our customers and their passengers. Nissan has investigated the issue of false activation on its Automatic Emergency Braking (AEB) system extensively and, in consultation with NHTSA, launched field actions notifying affected customers of a software update that improves MY17-18 Rogue AEB/FEB system performance. On some affected vehicles, vehicle owners may experience false-positive activation by the AEB system in unique road conditions, such as specific railroad crossings, bridges, and low hanging traffic lights. The update to the FEB/AEB system software is designed to improve system functionality. Customers are invited to bring their vehicle to an authorized Nissan dealership where the update will be applied at no cost."



Walsh is unconvinced. "I don't feel safe driving it anymore. I don't feel safe putting my family in it, so I don't want the car," she said.

In regards to Walsh's car, the automaker said: "Nissan will not comment on the subject of a customer's pending legal claim."

Automakers insist the technology will save lives and continues to improve. But there is no federal standard, so each system is a little different. Carmakers have at least 49 different names for the technology.

Additional automakers who have had complaints of phantom autobraking reported to NHTSA responded to CBS News' request for comment:

Fiat Chrysler Automobiles (FCA): "FCA vehicles meet or exceed all federal safety regulations. Nevertheless, we continuously monitor their performance in the field, and respond accordingly. Vehicle safety is a top priority at FCA."

Toyota: "We remain committed to NHTSA's voluntary automatic emergency braking (AEB) goal established in 2016 and we have made AEB standard across most of our lineup. IIHS estimates that AEB may help prevent 28,000 crashes and 12,000 injuries by 2025."

Mercedes: "I'd point out first that these systems are driver assistance systems which, simply put, are not meant to take the place of a driver's responsibilities. It should be noted too that all such assist systems can be overridden by the driver. So, for example, if the vehicle's Active Brake Assist activates because it senses a dangerous or ambiguous situation, all the driver has to do is give it gas and the vehicle comes back up to speed.

"In terms of reports of the alleged uncommanded braking issue you cite below, we have not seen any verified instance of it. Rather, for example, where the system engaged it sensed that the vehicle was closing too fast on the vehicle in front of it. If a driver wants to be closer than what safety considerations might dictate, he or she can simply hit the gas pedal and override the system.

"These systems are getting more and more sophisticated. Moreover, enhanced versions will continue to benefit from new inputs and be able to more accurately assess an ever-broader variety of situations likely to be encountered."

Honda: "To show you exactly what we tell vehicle owners about our version of Automatic Emergency Braking, I've attached the relevant pages from the 2020 Honda Accord Owner's Guide. We call our system the Collision Mitigation Braking System (CMBS), and we are quite open about its potential limitations. On page 513, under the heading "Important Safety Reminder" it reads, "The CMBS is designed to reduce the severity of an unavoidable collision. It does not prevent a collision nor stop the vehicle automatically. It is still your responsibility to operate the brake pedal and steering wheel appropriately according to the driving conditions.

"CMBS uses a combination of forward looking radar and cameras in an attempt to detect potential collisions with vehicles, pedestrians or objects, but it is not capable of detecting everything every time. Depending on conditions (see pages 517-519), it also may not be able to stop the vehicle before a collision. Thus, we recommend that drivers pay attention and stay in control of the vehicle at all times. Since the AAA study calls out pedestrian testing, please pay particular attention to the limitations listed on page 519.

"The CMBS may also activate at times when drivers don't believe it should, and our Owner's Guide provides a few such potential scenarios on pages 520-521.

"Ultimately, CMBS is meant to aid the driver to reduce the severity of a potential unavoidable collision. While research continues toward true automated vehicles in the future, CMBS is not yet an automated vehicle technology capable of operating a vehicle unsupervised. Thus, we recommend that drivers concentrate on the driving task and maintain control of their vehicle at all times."

Volkswagen: "At Volkswagen Group of America we pride ourselves on our vehicle safety technology and take our commitment to customer safety very seriously. While we remain confident in our safety systems such as autonomous emergency braking, we continue to fully cooperate with NHTSA and other appropriate agencies to evaluate these important and in some cases, life-saving technologies."