The letter, dated February 4 and first reported by Reuters[1], was in response[2] to a request from Alphabet's GOOG [3], -0.68% GOOGL, -0.45% Google[4] to interpret how federal vehicle-safety and driving regulations could affect its self-driving vehicles.
"No human occupant of the [self-driving vehicle] could meet the definition of "driver"...given Google's described motor vehicle design", NHTSA's letter said.
Google submitted a proposed[5] design for one of its self-driving cars to the NHTSA in November in which it stated that the vehicle had "no need for a human driver" since its AI systems could control the journey from start to finish.
The redefinition of "driver" by the National Highway Traffic Safety Administration is an important break for Google, which is developing self-driving cars that get around without steering wheels, pedals - or even the need for a person to be inside.
According to BBC News[6], the legal breakthrough marks a shift in regulator policy, as previously an automobile without a human driver could not be considered road legal, while paving the way for the production of vehicles which do not require steering wheels or pedals. The automakers also complain that the regulators are delaying the testing process and deployment of these vehicles on road.
Still, driverless cars may have many roadblocks to clear before they are manufactured and sold in large numbers, The Associated Press said[7], pointing out that the NHTSA "rejected many of Google's claims that its cars met federal auto safety standards".
"In this instance, an item of motor vehicle equipment, the(Self-Driving System), is actually driving the vehicle", said the letter, addressed to Chris Urmson, the USA company's director responsible for its SDV project.
However, the NHTSA's letter notes that these features could present safety issues because the human could decide to try and take control, which could conflict with the car's system.
NHTSA said the move to driverless cars began with antilock brakes, air bags, automatic-emergency braking, and, most recently, with crash- and lane-departure warnings.
So the way Google describes the vehicle, NHTSA does not see it is practical for a human to take over the actual driving of it.
Google's fleet of prototype driverless cars rely on sensors and software to complete journeys.
