In Petaluma:

Caltrans will close Northbound Hwy. 101 Tuesday night from 11 p.m.-5 a.m.  and the northbound on-ramp from eastbound Old Redwood Highway will be closed 10 p.m.-5 a.m. During those hours, traffic will take a short detour onto the Gravenstein Highway.

Southbound Hwy. 101 will be closed Wednesday night from 10 p.m.-5 a.m., as will the southbound on-ramp from westbound Old Redwood Highway. Traffic will be detoured onto Petaluma Blvd. N. and back onto Hwy. 101 at East Washington Street.

Crews are building a new bridge at the Hwy. 101/Old Redwood Highway intersection as part of the Marin-Sonoma Narrows widening project.

In Santa Rosa:

Caltrans has scheduled temporary closures of Hwy. 101 at Airport Blvd. Wednesday night from 11 p.m.-5 a.m. while a contractor makes adjustments to the recently installed falsework (temporary support structure) for the new Airport Blvd. bridge.  CHP will perform 5- to 10-minute traffic breaks on northbound and southbound U.S. 101, then will reopen the road to traffic.