Waymo and other robotaxi operators face increased scrutiny (and possible new federal requirements) over how their autonomous vehicles interact with emergency services, a regulatory risk that is increasingly difficult for the industry to ignore.

Rep. Kevin Mullin (D-Calif.) is the latest lawmaker to pressure the industry with a bill that would direct federal regulators to set national minimum safety standards for autonomous vehicle operators. The proposed legislation, which is expected to be introduced in Congress this week, follows a series of incidents in which autonomous vehicles blocked ambulances and fire trucks, entered active crime scenes and failed to recognize safety signs such as traffic cones and flares.

A TechCrunch investigation earlier this year identified a series of incidents in which Waymo relied on first responders to manually drive its vehicles when they encountered problems.

The legislation, called the AV Emergency Response Coordination Act, was unveiled Tuesday during a news conference in San Francisco, a testing center for autonomous vehicles and where hundreds of Waymo robotaxis already ferry paying customers. San Francisco Mayor Daniel Lurie, San Francisco Fire Chief Dean Crispen and Advocates for Highway and Auto Safety President Cathy Chase also spoke at the press conference.

“We have seen a disturbing and, frankly, unacceptable number of incidents where autonomous vehicles inadvertently interfere with emergency services,” Mullin said during the press conference.

Crispen said that while the fire department has worked with AV operators, a series of incidents and a continued pattern of behavior show changes need to be made. He noted that robotaxis pick up and drop off passengers directly in front of fire stations and ambulance deployment facilities, obstructing emergency access.

Mullin’s bill proposes requiring AV companies to provide clear emergency protocols for first responders, establishing a 24-hour hotline that gives public officials direct access to these companies, and directing the National Highway Traffic Safety Administration (NHTSA) to develop national minimum emergency response standards. The bill would also create a process that would allow public officials to “geofence” autonomous vehicles, a term that refers to imposing limits on where these vehicles can operate during emergencies or other ongoing safety hazards.

For autonomous vehicle operators, that geofencing provision could matter as much as the safety standards themselves: It would give city and public safety officials real-time leverage to restrict where robotaxis can travel, rather than waiting for companies to self-regulate.

Waymo responded that it has “long supported” a federal framework to set standards for autonomous vehicles.

“Similarly, we support efforts to standardize how AV developers interact with first responders,” Waymo said in a statement emailed to TechCrunch. “Our emergency response protocols, along with our extensive training with first responders, are a critical component of our operations in the US. Establishing minimum guidelines would provide the entire industry and public safety community with a consistent framework, ensuring first responders have the resources and certainty they need every time they encounter an autonomous vehicle on the road.”

Mullin is not alone in criticizing autonomous vehicle operators. Over the past few weeks, elected officials and federal regulators have expressed concerns about autonomous vehicles and how they have interfered with first responders.

In early July, NHTSA Administrator Jonathan Morrison sent a letter to autonomous vehicle developers saying the agency had “identified a clear pattern of driverless autonomous vehicles interfering with law enforcement and other first responders.” The letter demanded that AV developers submit “fixes” to the problem by the end of the month, a deadline that has already passed, putting pressure on companies like Waymo, Zoox and others to show progress or risk further federal action.

Mayor Lurie has called on California regulators to strengthen rules for autonomous vehicles following a hours-long July 4 traffic jam in San Francisco, compounded by Waymo robotaxis that had lost power, blocking key streets. Since then, Lurie has pressured state regulators to establish new rules to prevent problems like the traffic jam incident and a widespread power outage in December that stranded dozens of Waymo vehicles.

“Residents and visitors should be able to take an AV, public transportation or bike around our city safely, and they should also trust that our police and fire departments can contact them in an emergency,” Lurie said, speaking in support of Mullin’s proposed bill during the news conference.