In early July 2023, Caltrans began a paving and concrete slab replacement project on a three-mile stretch of Highway 12 in Santa Rosa between Llano Road and Farmers Lane.
As part of this project, Caltrans has planned a weekend closure in both directions of Hwy 12 between Fulton Road and Dutton Avenue beginning at 8:00 p.m. on Friday, September 22 through early Monday morning, September 24, 2023. There will be a full closure along this section of Hwy 12 between 8:00 p.m. and 8:00 a.m. each night. During the day, between the hours of 8:00 a.m. and 8:00 p.m., there will be one lane open in each direction. The weekend closure will allow Caltrans to expedite construction, completing work that would typically take weeks of night work and completing them over the long closure weekend.
Weather is a consideration for this project. Paving is best done when the weather is warm. If temperatures dip into the 40s, there's a good chance the pavement won't bind properly, and the newly laid asphalt will need to be replaced. The same holds true for the concrete sections. Warm weather helps the concrete to cure properly, which is essential to getting the road open on time. Naturally, the best season in which to pave or pour concrete is summer, when warm weather is the norm, however, Caltrans is very aware that summer and fall is fire season, and our community has been impacted by fires in recent years.
During the weekend closure, Caltrans is prepared to open at least one lane to allow emergency vehicles to pass through if necessary. Additionally, Caltrans will postpone the weekend closure if a Red Flag wind or fire warning is issued.
Closure Limits

Daytime 8 a.m. to 8 p.m.: One lane open in each direction

Night Time Closures 8 p.m. to 8 a.m.

Detours
Eastbound Detours
- Right onto Fulton/S Wright Rd,
- Left on Sebastopol Rd
- Left onto Dutton Avenue
- Right onto the eastbound State Route 12 onramp
-OR-
- Left onto Fulton/S Wright Rd,
- Right onto 3rd St
- Right onto Dutton Ave
- Left turn to merge on the eastbound State Route 12 onramp
Westbound Detours
- Take the Dutton Avenue offramp
- Right at Dutton Avenue
- Left at W 3rd St
- Left at Fulton/S Wright Rd
- Right turn onto SR 12 WB
-OR-
- Take the Dutton Avenue offramp
- Left at Dutton Avenue
- Right at Sebastopol Rd
- Right at Fulton/S Wright Rd
- Left onto westbound State Route 12
Caltrans District 4 project webpage