An emergency project to repair Highway 41 at Los Altos Road near Atascadero is now underway.
Caltrans says the project is necessary due to a collapsing drainage culvert under the highway which resulted in a sinkhole along the shoulder.
Construction is scheduled to take place Sunday through Friday during the overnight hours from 8 p.m. until 6 a.m. and during the daytime Monday through Thursday from 8 a.m. until 4 p.m. and on Fridays from 8 a.m. until 2 p.m.
Caltrans says delays are not expected to exceed 15 minutes.
Officials also warn the roadwork will be noisy and could affect nearby residents.
The project is scheduled to be complete in early September.