Driverless Waymo Slips Past Barricades and Into Denver Farmers MarketGuessing HeadlightsOlivia RichmanMon, September 21, 2026 at 10:25 PM UTCAdd us on GoogleImage Credit: 9 News.A Waymo with nobody behind the wheel rolled into a Denver farmers market Sunday morning while vendors were still setting up, leaving workers with an unusual problem: How do you tell a driverless car it has gone somewhere it should not be?The vehicle appeared on South Pearl Street around 8:40 a.m. Sept. 20, according to 9NEWS. Assistant market manager Shari Wilkins said barricades and signs were already in place, and workers tried to stop the Waymo after it entered the market area.That was easier said than done. There was no driver to flag down, no open window to knock on and nobody behind the wheel to tell to turn around.AdvertisementAdvertisementWorkers instead began clearing people from its path while trying to usher the car back out.Unexpected GuestThe South Pearl Street Farmers Market normally takes over the 1400 and 1500 blocks of South Pearl Street on Sunday mornings. Its official schedule lists the market from 9 a.m. to 1 p.m., meaning the Waymo arrived during the final stretch of vendor setup.Wilkins told 9NEWS the vehicle would stop and then begin moving again as workers tried to figure out what it was going to do.Market manager Theodore Subbotin described the basic complication: with no person inside, workers could not handle the situation the way they would with a conventional car that mistakenly entered a closed street.AdvertisementAdvertisement"There is no driver or anyone in the car," Subbotin told the station. "You can't get the car out like you would with a normal driver."Waymo told 9NEWS the vehicle had been navigating toward a destination on Pearl Street. The company said the vehicle recognized the situation and moved out of the area.What remains unclear is how it entered the market area despite the temporary closure in the first place. Subbotin said access required getting around barriers.Changing StreetsTemporary closures are precisely the kind of changing road condition autonomous vehicles have to interpret without assuming that yesterday's route still works today.AdvertisementAdvertisementWaymo says its vehicles combine previously mapped road information with what their sensors encounter in real time. The company has also described a fleet-response system that allows its autonomous Driver to ask remote personnel for additional context when it encounters an unusual situation.One example Waymo gives is a confusing arrangement of construction-zone cones. A remote fleet-response agent can examine the vehicle's camera feeds and provide additional information about what the cones appear to mean, while the autonomous driving system remains in control of the car.The South Pearl Street episode happened less than three weeks after Waymo began welcoming its first public riders in Denver on Sept. 1. The company said that rollout brought its newest vehicle platform and next-generation Waymo Driver to the city.Denver had already supplied the system with at least one other lesson in how quickly streets can change.Another DetourIn August, a Waymo spent roughly an hour navigating around construction on East Colfax Avenue before becoming stranded outside the active work area, according to Denverite.AdvertisementAdvertisementConstruction workers eventually placed cones around that vehicle. Waymo told Denverite at the time that the car had alerted the rest of its fleet to avoid a blockage but became stranded in the process of navigating around it.The farmers market presented a different version of the same broad challenge. South Pearl Street was still a street, but on Sunday morning it was in the process of becoming something else.For the people setting up tents and moving vendor vehicles into position, the transformation was obvious. For the Waymo heading toward a Pearl Street destination, it became something the car had to recognize after it was already there.Waymo told 9NEWS it is learning from the incident as it continues operating in Denver.If you want more stories like this, follow Guessing Headlights on Yahoo so you don't miss what's coming next.