(Reuters) — U.S. vehicle safety regulators have said the artificial intelligence system piloting a self-driving Google car could be considered the driver under federal law, a major step toward ultimately winning approval for autonomous vehicles on the roads.

The National Highway Traffic Safety Administration told Google, a unit of Alphabet Inc (GOOGL.O), of its decision in a previously unreported Feb. 4 letter to the company posted on the agency’s website this week.

Google’s self-driving car unit on Nov. 12 submitted a proposed design for a self-driving car that has “no need for a human driver,” the letter to Google from National Highway Traffic Safety Administration Chief Counsel Paul Hemmersbaugh said.

“NHTSA will interpret ‘driver’ in the context of Google’s described motor vehicle design as referring to the (self-driving system), and not to any of the vehicle occupants,” NHTSA’s letter said.

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