Waymo’s taxis seem to be vying for the top spot on the driverless jam scoreboard if such a thing ever existed. The autonomous taxis, which take the form of Jaguar I-Pace EVs and ply the streets of San Fransico and Arizona, have been a frequent sight for residents. But following reports of five cars blocking a residential street in SF last month due to fog, it’s time for Arizona’s fleet to take the headlines.

The jam occurred along Roosevelt Street in Downtown Phoenix last month and saw 12 Waymos get “confused” and ended up clogging the road. According to one TikTok user, police attempted to intervene, but as there were no human drivers behind the wheel, the cops weren’t exactly able to tell the befuddled Waymos where to go.

Related: Waymo Robotaxis Create Five-Car Roadblock After Freaking Out Over San Francisco Fog

@azchronicless Technology is the future #arizona #waymo #trafficjam #traffic #downtownphoenix #future #maricopa #devinbooker #screammovie ♬ Trap Mafia – Lastra

Waymo blamed the jam on a software glitch, reports the AZ Mirror. A spokesperson said, “As safety is central to our mission, our autonomous driving technology prioritizes the safest driving path with the information it has at any given moment. Sometimes, that means our vehicle will pull over or come to a stop if it’s assessed to be the safest course of action in that instance, as happened here. We identified the software that contributed to this situation and made appropriate updates across our fleet within 24 hours.”

However, the incident is the latest in a long line of run-ins with authorities for driverless cars. While no injuries have been reported, it’s not the first time that the behavior of autonomous cars when being directed by first responders has been called into question. In San Francisco, a fire department official claimed that incursions of autonomous vehicles have now become a “daily occurrence.” In one such incident a driverless car kept creeping towards a firefighter who was yelling at it to stop and would only do so when those at the scene smashed the car’s window.

How driverless cars should respond to human instructions — particularly from those in law enforcement — is a concern that evidently has room for improvement. Whether such a solution can be found in the near future is another question.

 Software Bug Causes Waymo Traffic Than Usual In Bizarre Driverless Jam