Malfunctioning railroad arms at railroad crossings are continuing to be a problem in Petaluma since freight train service resumed in mid-July.

Traffic was backed up onto North McDowell Boulevard on Aug. 18 due to a malfunctioning railroad crossing arm at the tracks on Southpoint Boulevard.

The railroad arms switched on about 8:45 a.m., stopping traffic, but with no train approaching. Traffic quickly began piling up onto McDowell Boulevard and motorists eventually began weaving their way around the railroad arms.

Petaluma police arrived on the scene a little after 9 a.m. to lift the arms and direct traffic across the tracks until signal technicians were able to shut the signals off about an hour later.

In previous weeks, there have been reports of railroad crossing arms malfunctioning and creating traffic jams at the intersections of Lakeville and D streets, and at East Washington and Lakeville streets. A similar issue has been reported in Schelleville, as well.

Mitch Stogner, executive director of the North Coast Railroad Authority, said a trigger mechanism for the railroad arms isn't working properly and that they have a team of people looking into the problem.

"When switching takes place with trains, that is when cars are dropped off, stopped or backing up, the crossing signal arms should go down, but for some reason they're staying down. In some cases they're going up and down, so it's the trigger mechanism that's not behaving properly for some reason."

Stogner said that the NCRA is working with engineers with HNTB, a railroad bridge design firm in Oakland, and the Northwestern Pacific Railroad Company's signal experts with Summit Signal to fix the problem as quickly as possible.

"It's like we said early on, in the first 30 to 60 days of operations we'll be having to get the bugs worked out," said Stogner. "The rails are rusted from not having been used in a long time and we have signal equipment that is state of the art. Having those two things work in synchronicity is going to take some time, but we are working to get them resolved."

Freight service resumed on July 13 for the first time since 2001, when federal transportation regulators halted service on the storm-damaged route. The NCRA leases the tracks to a private short-haul rail operator, the Northwestern Pacific Railroad Co. The trains haul goods during daylight hours and make one round-trip on the line, three days a week on Mondays, Wednesdays and Fridays.

(Contact Yovanna Bieberich at