At the end of a crowded public hearing Thursday that included nearly six hours of public testimony, state regulators voted to allow two autonomous vehicle companies to operate driverless taxis 24 hours a day and deploy an unlimited number of vehicles in San Francisco.

The California Public Utilities Commission voted 3-1 to allow Waymo, backed by General Motors and Cruise, and the Alphabet company, to expand services both autonomous vehicle operators had been offering, with limited vehicles and hours of operation, for the past year or so.

“Today’s permit marks the true beginning of our commercial operations in San Francisco,” said Tekedra Mawakana, co-CEO of Waymo, in a blog post on the company’s website. “We’re incredibly grateful for this vote of confidence from the CPUC, and to the communities and riders who have supported our service.

“We can’t wait for more San Franciscans to experience the mobility, safety, sustainability and accessibility benefits of full autonomy for themselves — all at the touch of a button.”

While the approval represents a benchmark for autonomous vehicle innovators that have been working for years to perfect driverless cars that rely on high tech sensors and advanced software programs to “see” other vehicles and potential hazards while navigating roadways, pushback on the decision came from multiple quarters, including San Francisco first responders who cited numerous issues they’ve encountered with driverless vehicles in the northern California city.

Reports have included vehicles blocking pathways for emergency vehicles, rolling over fire hoses and infringing in areas of active first responder incidents.

San Francisco Fire Department Chief Jeanine Nicholson spoke at the separate public hearing on Monday, citing 55 written reports detailing incidents in which robotaxis interfered with the work of firefighters.

“They are still not ready for prime time because of the way they have impacted our operations,” Nicholson said, per The Associated Press.

In a June 22 letter to the California Public Utilities Commission, Tracy McCray, president of the San Francisco Police Officers Association, urged commission members to reject Waymo and Cruise’s applications for expanded service, until “further research is done to help understand the impact these vehicles have to the safety of not only other vehicles on the roadway but pedestrians as well.”

“While we applaud the advancements in technology, we must not be in such a rush that we forget the human element and the effects such technology unchecked can create dangerous situations,” McCray wrote. “Delays of even seconds in our line of work can be a matter of life and death.”

In the letter, McCray also cited a recent incident in which an autonomous vehicle hindered access by emergency vehicles to the scene of a mass shooting incident in San Francisco’s Mission District neighborhood.

For their part, robotaxi operators tout their safety records following millions of miles of on-road testing.

Out of 3 million driverless miles, a Cruise car has not been involved in a single fatality or life-threatening injury, according to the company per CNN. In a February review of its first million driverless miles, Waymo said its cars caused no reported injuries and that 55% of all contact events were the result of a human driver hitting a stationary Waymo vehicle.