Expect Traffic Delays on Highway 41 as Caltrans Carries Out Rock-Scaling Work

Drivers on Highway 41 between Morro Bay and Atascadero should prepare for 10-15 minute delays on Wednesday, December 3, as Caltrans crews carry out rock-scaling work to stabilize eroding hillsides.

Caltrans made the announcement on Tuesday, advising motorists to plan extra travel time. 

The traffic control is scheduled on Wednesday from 8 a.m. through 3 p.m., along the stretch of Highway 41 between Old Morro Road and Toro Creek Road.

The California Highway Patrol recommended US-101 and SR-46 as alternate routes for drivers wishing to avoid the controlled section of SR-41. These alternatives provide a steadier traffic flow and may reduce travel time for drivers. 

Caltrans will temporarily control traffic on this route while crews work to address hillside safety concerns caused by loose rock and erosion ahead of winter rains. 

The agency further noted that vehicles moving in both directions will be guided by highway crews, which can result in a delay of about 10 to 15 minutes. 

Expect delays Dec 3rd, SR-41 Morro Bay to Atascadero, daytime road construction. Maybe quicker be quicker to travel US-101 from San Luis Obispo or SR-46. pic.twitter.com/F5kOkDJ2zl

— CHP San Luis Obispo (@ChpSlo) December 3, 2025

The traffic interruptions are necessary to stabilize slopes above the roadway where loose rocks have been identified as a future hazard. Crews will remove the unstable rocks before the weather to reduce the risk of rockfalls and keep the highway operational during storms.

The advisory is part of a broader county network affecting Santa Barbara, San Luis Obispo, Monterey, San Benito, and Santa Cruz Counties. 

Drivers are encouraged to allow extra travel time or consider alternate routes to avoid delays.

According to the Caltrans Geotechnical Manual, rockfalls in California commonly occur during rainstorms, when water washes out the soil and smaller material that supports heavier rocks. 

Rock scaling involves removing loose material from hillsides using hand tools or mechanical equipment. It is often paired with additional stabilization methods. Because slopes continue to weather over time, scaling may need to be repeated every two to 10 years.

Rock removal or blast scaling takes the process further by removing large or unstable rock sections through controlled blasting or chemical expansion, as stated by Caltrans. 

In addition to the SR-41 closure, Caltrans District 5 also announced lane closures on US-101 in San Luis Obispo. The overnight work is scheduled from the evening of December 3 through the early hours of December 4. 

The construction work on these routes is expected to be carried out from 8 p.m. and 6 a.m. There will be multiple short-term full closures along the US-101 highway entrances and exit ramps during these hours. 

Affected routes include locations at Arroyo Grande, Oak Park Blvd, Price Street, Avila Beach Drive, Marsh Street, Grand Avenue, Broad Street, Osos Street, Toro Street, and California Blvd. During the work, short lane closures may occur with alternate routes wherever required. The work will include guardrail repair and installation, highway striping, and concrete placement.