Caltrans officials say they believe a problem in new software may be responsible for a malfunction that left about 70 onramp meters stuck on red as the Sacramento area afternoon commute began today.
Caltrans spokesman Mark Dinger said sabotage was not suspected.
Reports of problems with the meters designed to regulate merging traffic began coming in about 3:45 p.m.
Dinger said only the meters that were activated at the time were affected. About 30 meters that were scheduled to come on later in the afternoon appeared to be working properly.
Dinger said Caltrans was able to turn off some meters remotely, but Caltrans employees and CHP officers were dispatched to turn off others on site. He said Caltrans is working to correct the problem.
He said some of the meters will be back online Thursday and all should operational by Monday. He said they will be dealing with them as corridors and not as individual signals.
All the meters are off. Caltrans officials said if motorists encounter a red-light meter to treat it as stop signal and proceed with caution.
Areas affected included Interstate 80 from Davis to Roseville, Highway 50 from West Sacramento to El Dorado Hills, Highway 99 from downtown Sacramento to Elk Grove, I-5 from downtown Sacramento to Elk Grove, and Capital City Freeway from Highway 50 to the Interstate 80 interchange.
Although they would not have chosen to do it this way, Caltrans engineers will have an opportunity to study the affects unregulated onramp traffic on the freeway system over the next few days, Dinger said.