The lasers, radar systems and cameras that enable autonomous driving and emergency braking systems are technical marvels that can make roads safer, but the technology has limitations consumers should be aware of.
- Autonomous systems don’t get tired or distracted, but they still can’t replace human drivers in all instances.
- Obstacles as large as a fire truck and as small as a bug can flummox autonomous systems.
- Some safety systems, such as automatic emergency braking, have actually caused accidents.
Autonomous driving and safety systems have been available for more than a decade, but the technology is still developing, and faces a range of challenges.
As experts from the National Transportation Safety Board (NTSB) have pointed out, autonomous systems can have problems when the car ahead suddenly changes lanes. This is referred to as a “cut-out scenario“. While sensors are good at detecting the lead vehicle changing lanes, they are less adept than alert human drivers at determining WHY it turned. Was the lead vehicle merely changing lanes to enter a rest stop, or is there a stopped fire truck immediately ahead? Autonomous systems still take precious seconds to figure it out, and that can lead to accidents.
Self-driving cars use a variety of sensors. This technology is constantly changing. (Photo: Getty Images)
Commercially viable automatic braking systems are approaching their 17th birthday — Mercedes and Honda offered systems back in 2003 — but would you trust a teenager with your life? Toyota had to recall 31,000 Avalon sedans and Lexus models in 2015 to repair emergency collision systems that mistakenly triggered over commonplace objects on the road, such as metal plates. And just this summer, Nissan had to recall some Rogues from 2017 and 2018 for false-positive automatic braking issues. The National Highway Traffic Safety Administration reports 843 complaints from Rogue owners that the system activated the brakes without warrant, causing 14 crashes and five non-serious injuries.
Even insects pose a significant challenge to self-driving cars. Bug splatter on a windshield may be annoying, but human drivers can usually see around it. By contrast, the cameras and sensors used for automatic driving can be a fraction of an square inch in size… a kamikaze katydid can completely block one. The use of multiple sensors can reduce the risk from bug splatter, as can aggressive countermeasures. Ford, for instance, has been working on a system that combines an air-curtain to blow insects away from sensitive lens with washer nozzles to clean away any that get through.
WHY THIS MATTERS
Autonomous vehicles are getting ever-more-powerful computer systems, but fatal accidents involving Tesla and Uber show they are still far from perfect. These systems need to see their environment to function, and that requires accurate sensors that work reliably in a wide range of situations over the life of the vehicle.