Why Dozens of Waymo Robotaxis Got Stuck and Towed in San Francisco’s July 4th Gridlock

Dozens of Waymo robotaxis ground to a halt and had to be towed after San Francisco’s Fourth of July fireworks show drew a record crowd to the Golden Gate Bridge, leaving stranded passengers, gridlocked streets and at least one driverless car rolling through a lit firework in the middle of an intersection. The episode has reopened a question city officials and NHTSA have both been asking this year: what happens when a fleet of computer-driven cars meets a traffic jam nobody programmed for.

Waymo operates 577 robotaxis and provides roughly 500,000 paid rides a week across 10 US cities, and San Francisco is its home market. On the night of July 4, unplanned road closures around the fireworks display, a surge of foot and vehicle traffic estimated at more than 100,000 people, and hours of gridlock in the Presidio combined to trap a large cluster of the company’s vehicles on a handful of streets. Some cars idled in place so long that their batteries ran down, and tow trucks had to haul them away with passengers still inside or after they had been let out on the sidewalk.

The Firework, the Passenger and the Viral Video

The most widely shared moment of the night came from the Mission District, where a Waymo carrying a passenger rolled directly over an exploding firework. Video of the encounter shows colorful smoke billowing around the white SUV as a passenger inside can be heard asking whether the car was on fire. Waymo told reporters no injuries were reported, the vehicle itself was undamaged, and the company reached out to the rider afterward. A separate, empty Waymo also drove over a lit firework elsewhere in the city that same night.

Away from the fireworks themselves, the bigger practical problem was congestion. One rider said he was trapped behind a cluster of stalled Waymos for four hours near the Palace of Fine Arts. Another said his children were stuck for roughly the same stretch of time before a tow truck finally arrived to haul away the vehicle blocking their path. Clips of rows of idle, sensor-topped Waymos sitting nose to tail circulated widely online within hours, reviving a debate that has trailed the company all the way back to a separate incident last winter.

What Waymo Says Happened

In a statement, Waymo said extreme traffic congestion in northern San Francisco disrupted normal operations for several of its vehicles, and that the company’s priority is keeping the city moving safely, especially at major celebrations. A spokesperson said the team worked to clear the vehicles from the area in coordination with local authorities and emergency services, and that Waymo is always evaluating ways to strengthen its resilience through major traffic disruptions.

The company confirmed the stranded vehicles were concentrated on a limited number of streets in the Presidio, and that the combination of heavy traffic, an unusually large crowd, and unplanned road closures around the bridge produced congestion beyond what its routing systems anticipated. Some cars were able to work their way out once traffic eased. Others simply ran out of charge while idling and needed a tow. Waymo said it had preemptively embedded a staffer at the San Francisco Emergency Operations Center ahead of the fireworks show and worked with first responders throughout the night, and that its own roadside assistance team is responsible for coordinating tows in situations like this one.

City Hall’s Response

Mayor Daniel Lurie’s office acknowledged the disruption without singling out Waymo by name. A spokesman for the mayor, Charles Lutvak, said public safety was the top priority that night and that the city was glad most people enjoyed the fireworks safely, while acknowledging that with more than 100,000 people in the area, some residents experienced delays getting home. Lutvak said the city plans to have conversations with its public and private partners, a category that includes Waymo, to make the experience smoother the next time San Francisco hosts an event of similar size.

An Echo of December’s Blackout

The Fourth of July gridlock is not the first time a mass event has exposed weaknesses in how Waymo’s fleet handles unpredictable, large-scale disruption in San Francisco. In December 2025, a Pacific Gas and Electric power outage knocked out traffic signals across the city and stranded roughly 64 Waymos at intersections, with the company forced to send staff and tow trucks to retrieve them. In two of those cases, first responders had to get behind the wheel themselves to move the driverless cars out of the way. That blackout prompted a San Francisco Board of Supervisors hearing in March, where Waymo acknowledged it should have worked more closely with the city while the outage was underway.

Waymo’s cars are programmed to treat any intersection with a non-functioning traffic light as a four-way stop, a safe default that still slows the flow of traffic when dozens of vehicles apply the same cautious logic at once. Getting a stalled Waymo moving again after a signal failure typically requires what the company calls a confirmation check, carried out remotely by a human operator who can approve the vehicle’s next move but cannot actually steer it. That process, designed as a safety layer, can also become a bottleneck when many vehicles need attention within the same short window.

What This Means Beyond San Francisco

Robotaxis now operate in roughly 10 US metro areas, and Waymo has continued expanding through 2026, most recently reaching Miami. Every city hosting large-scale public events, from championship parades to holiday fireworks to concerts, will eventually face some version of the same test San Francisco failed on July 4: can an autonomous fleet cope with sudden, extreme congestion around a planned gathering, or does it need advance coordination with organizers the way transit agencies and ride-hail dispatchers already build into their own event planning.

Federal regulators have been paying closer attention to exactly this kind of scenario. NHTSA sent a directive to autonomous vehicle developers earlier this month demanding that driverless cars stop interfering with first responders and law enforcement, citing what the agency called a clear pattern of autonomous vehicles blocking emergency vehicles nationwide. The agency has asked companies to present solutions by the end of the month. The Fourth of July gridlock did not involve emergency vehicles being blocked in the way NHTSA’s directive addressed, but it lands in the same broader conversation about whether robotaxi operators can reliably manage their fleets when a city’s streets stop behaving normally.

What Riders Should Know

For everyday riders, the practical lesson is simple: avoid booking a Waymo, or any robotaxi, in or near an area hosting a major public event with road closures, especially in the hours immediately before and after. Waymo’s app does account for some road closures, but the company’s own account of the July 4 night shows its routing did not fully anticipate the scale of the crowd or the duration of the congestion. Riders who do get stuck in a stalled robotaxi can request help through the app, and Waymo says its roadside team monitors vehicles that stop moving for an extended period, though as the Presidio backup showed, a tow can still take hours to arrive once a large cluster of vehicles needs help at the same time.

Anyone caught in a stalled robotaxi for an extended period can also exit and continue on foot or hail a traditional rideshare instead of waiting for a tow, above all if a route around the closure is walkable. Waymo’s app shows a live map of the vehicle’s position and any detected slowdown, which can help a rider judge whether to sit tight or find another way home. For families planning around future fireworks shows, parades or similar large gatherings in cities where Waymo, Zoox or other driverless services operate, booking a pickup well outside the footprint of expected road closures remains the safest way to avoid getting caught in a repeat of what happened in the Presidio.