Highway 101 Bridge Shift Delayed, Will Start Monday Night

North Bay drivers avoided having their commute changed for a few extra days thanks to the weather.

Caltrans will have both directions of Highway 101 share the southbound bridge over State Route 116 in Petaluma while a new bridge is built. The agency was planning to make the switch Friday night, but cold and foggy weather kept the work from starting, Caltrans said in a press release Monday.

"Northbound traffic will to be shifted to the left across the median to the southbound bridge," Caltrans said in the press release. "There will be two northbound lanes and two southbound lanes sharing the same bridge. After passing over SR 116, northbound traffic will shift to the right and return to the original roadway."

Caltrans is replacing the bridges, which each have two lanes, no shoulders and were built in 1955. The new bridges will have three lanes in each direction and should be finished by mid-2015, Caltrans says on its website.

During the temporary lane shift, traffic directions will be separated by concrete barriers and the speed limit in the area will be 45 mph.

"It is essential for the safety of motorists and construction workers that this speed limit is observed," Caltrans said in the press release. "This speed limit will be enforced by the California Highway Patrol."

The construction will include the following lane closures:

• One lane of northbound Highway 101 will be closed from 11 p.m. to 6 a.m. Monday, Tuesday and Wednesday nights.
• One lane of southbound Highway 101 will be closed from 10 p.m. to 4 a.m. Monday and Tuesday nights.
• The northbound Highway 101 offramp to State Route 116 will be closed from 10 p.m. to 6 a.m. Monday and Tuesday nights.
• The northbound onramp from State Route 116 to Highway 101 will be closed from 10 p.m. to 6 a.m. Wednesday night.