A malfunctioning rail crossing signal snarled Thanksgiving Day traffic for several hours on College Avenue in Santa Rosa.
The signal lost power around 11 a.m., causing the gate arms to drop across the roadway.
"People are a little confused," said Paul Downing, a local train enthusiast who pulled over to observe the traffic tie-up.
Some drivers frustrated by the long lines snapped U-turns on College Avenue, while others waited and weaved through the gates one at a time. Santa Rosa police officers later directed traffic at the intersection.
Mike Milin, a signal engineer with Summit Signal Inc., drove from Napa to fix the problem. He said the power to the signal had been cut for an unknown reason.
He planned to lock the gates back into their upright position and alert the railway to ensure no trains operate in the area until the problem is fixed.
One of those caught in the traffic back-up was Mitch Stogner, executive director of the North Coast Railroad Authority, who stopped to offer officers his assistance.
"What a terrible inconvenience on Thanksgiving Day," he said.