Highway 12 Paving in Santa Rosa

In early July 2023, Caltrans began a paving project on a three-mile stretch of State Route 12 (SR-12) between Llano Road and Farmers Market Road in Santa Rosa to replace worn-out pavement. 

This section of Highway 12 is composed of two types of pavement.  From Llano Road to Fulton Avenue the highway is composed of asphalt, while the section between Fulton and Farmers Lane is composed of concrete slabs.  As such, different construction and paving strategy will be used to revamp the pavement.  

Route 12 Santa Rosa Map

Pavement Condition -

Caltrans will smooth out the new concrete before completing the concrete slab replacement portion of this project. In other words, the new concrete is not in its final condition. Using a grinder, Caltrans work crews will grind the rough concrete into a smooth surface before finishing this project. 


Upcoming weekend closures listed below: 

Caltrans chose to implement full nighttime and partial daytime freeway closures to accelerate the demolition and replacement of concrete slab work that may take up to a year if performed during typical nighttime lane closures. Also, full nighttime closures are safer for workers and motorists. 

Weekend Closure: Friday, March 22 - Monday, March 25 - Westbound Route 12 Only

Between Friday, March 22 and Monday, March 25 Caltrans will close lanes on westbound State Route 12 to demolish and replace existing concrete slabs. Eastbound Route 12 will not be affected. 

Caltrans will provide updates if work is postponed or cancelled due to weather.


FULL Nighttime Closures on Westbound Route 12

Friday, March 22 from 8:00 PM until 8:00 AM on Saturday, March 23.

Saturday, March 23, from 8:00 PM until 8:00 AM on Sunday, March 24.

Sunday, March 24, from 8:00 PM until 5:00 AM on Monday, March 25



One Lane Closure on Westbound Route 12 (One of two lanes will be closed)

Saturday, March 23 from 8:00 AM until 8:00 PM 

  Sunday, March 24 from 8:00 AM until 8:00 PM

Click here to read t.he traffic advisory


Weather has always been a consideration for this project.  Paving is best done when the weather is warm.  If temperature 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 hold true for the concrete sections. Warm weather helps the concrete to harden 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, given the history of wildfire in Sonoma County and the importance of SR-12 as an emergency route, Caltrans decided to perform the bulk of the work during the cooler months.