Tesla Inc. is readying a major upgrade of its driver-assistance software, but the top federal crash investigator says the move might be premature. Chief Executive Elon Musk last week said drivers would soon be able to request an enhanced version of what Tesla calls its "Full Self-Driving Capability." The upgrade is expected to add a feature intended to help vehicles navigate cities, expanding the suite of driver-assistance tools that had been designed mainly for highways.



The self-driving capability is not fully autonomous

Despite its name, Full Self-Driving doesn’t make cars fully autonomous, and Tesla instructs drivers to remain alert, with their hands on the wheel. Jennifer Homendy, the new head of the National Transportation Safety Board, said Tesla shouldn’t roll out the city-driving tool before addressing what the agency views as safety deficiencies in the company’s technology. The NTSB, which investigates crashes and issues safety recommendations though it has no regulatory authority, has urged Tesla to clamp down on how drivers are able to use the company’s driver-assistance tools.

"Basic safety issues have to be addressed before they’re then expanding it to other city streets and other areas," she said in an interview. Ms. Homendy also expressed concern about how Tesla software is tested on public roadways. Ms. Homendy called Tesla’s use of the term Full Self-Driving "misleading and irresponsible," adding that people pay more attention to marketing than to warnings in car manuals or on a company’s website. In Tesla’s case, she said, "It has clearly misled numerous people to misuse and abuse technology."

Mr. Musk has said Tesla’s advanced driver-assistance features prevent crashes and make driving safer. He has expressed mixed views about the Full Self-Driving system in recent months. "We need to make full self-driving work in order for it to be a compelling value proposition. Otherwise, people are, you know, kind of betting on the future,"



Customer's subscription interest in Tesla
In response to a question about customer interest in subscribing to Tesla’s Full Self-Driving package. Some safety advocates and transportation officials have raised concerns that drivers may be overestimating the capabilities of advanced driver-assistance systems such as Tesla’s. "We’re consistently hearing that it’s definitely a work in progress, so it’s just how do we make sure the public understands its limitations?"