WASHINGTON -U.S. auto safety regulators will extend a deadline for public input on General Motors and Ford Motor petitions seeking to deploy a limited number of self-driving vehicles without human controls like steering wheels and brake pedals.

The National Highway Traffic Safety Administration (NHTSA) on Thursday made the 30-day extension of the public comment on the automaker requests after cities like San Francisco and Oakland, California, state transportation agencies, the National Association of City Transportation Officials and others sought further time to analyze the exemption requests.

San Francisco said petitions raise "numerous complex technical and policy issues involving vehicle safety that necessitate significant analysis."

San Francisco noted it "is the location with the most intensive testing of automated vehicles to date... As such, we have valuable insights to offer and stand to be significantly affected by the outcome of the petition."

NHTSA has authority to grant petitions to allow a limited number of vehicles to operate on U.S. roads without required human controls.

Both automakers want to deploy up to 2,500 vehicles annually, the maximum allowed under law, for ride sharing and delivery services. Neither seek approval to sell self-driving vehicles to consumers.

GM and its self-driving technology unit Cruise in February disclosed they petitioned NHTSA for permission to deploy self-driving vehicles without steering wheels, mirrors, turn signals or windshield wipers.

Ford's petition submitted in July 2021 was previously undisclosed until NHTSA's publication last month.

Ford has said it intended to deploy a self-driving ride hailing and package delivery vehicle early in this decade.

GM wants to deploy its vehicle the Origin, which has subway-like doors and no steering wheels. GM says vehicles will require passengers to buckle seat belts prior to autonomous rides.

In 2018, GM petitioned NHTSA to allow a car built on a Chevrolet Bolt without steering wheels or brake pedals on U.S. roads. In late 2020, GM withdrew the petition.

  - Reuters