CR Finds Tesla’s Autopilot Lane Changing Doesn’t Work Well & Could Be Unsafe

The automaker Tesla recently updated its Autopilot software to allow certain cars to automatically change lanes. Tesla says it is an attempt to make driving “more seamless.” But Consumer Reports observed the opposite in its own tests of the feature, finding that it doesn’t work very well and could create potential safety risks for drivers.

Tesla added the update to its Navigate on Autopilot feature in April 2019 as part of a promised upgrade to its package of driver assist features. To use it, a driver must first turn it on, essentially giving the car permission to make its own lane changes. A driver can cancel an automated lane change that’s in progress at any time by using the turn signal stalk, braking, or holding the steering wheel in place.

In practice, CR found that Navigate on Autopilot lagged far behind a human driver’s skillset: The feature cut off cars without leaving enough space, and even passed other cars in ways that violate state laws, according to several law enforcement representatives CR interviewed. As a result, the driver often had to prevent the system from making poor decisions.

“The system’s role should be to help the driver, but the way this technology is deployed it’s the other way around,” said Jake Fisher, Consumer Reports’ senior director of auto testing. “It’s incredibly nearsighted. It doesn’t appear to react to brake lights or turn signals, it can’t anticipate what other drivers will do, and as a result, you constantly have to be one step ahead of it.”

Despite Tesla’s promises that self-driving cars are just around the corner, CR’s observations show that today’s vehicles seem far from fulfilling the promise of full autonomy. In addition, experts tell CR that the automatic lane change feature demonstrates the technological limits of Tesla’s current hardware.

David Friedman, vice president of advocacy at Consumer Reports, said that as it currently exists, Tesla’s automatic lane change function raises serious safety concerns. “The Navigate on Autopilot driver-assist feature overpromises and under-delivers, with lives on the line,” he said. “Tesla is showing what not to do on the path toward self-driving cars: release increasingly automated driving systems that aren’t vetted properly.

“Before selling these systems, automakers should be required to give the public validated evidence of that system’s safety—backed by rigorous simulations, track testing, and the use of safety drivers in real-world conditions,” Friedman said.

Today’s full report by CR is available online here.  This finding is in addition to existing concerns regarding the underlying Autopilot system already raised by CR and the National Transportation Safety Board, among others.

CR continues to advocate for Tesla to implement an effective feature to ensure the driver is aware, engaged, and ready to take over when the automation system is at or near its limits. This kind of feature would directly address the risk of people in the driver’s seat checking out and getting into crashes, as the NTSB documented in September 2017. Cadillac’s Super Cruise currently has the highest-rated ability to keep the driver engaged in CR’s first ranking of automated driving systems.