Starting Tuesday morning, motorists traveling both directions of State Route 154 and 246 will be driving through a partially completed roundabout near Santa Ynez.
Daytime land closures will be Monday through Thursday from 9:30 a.m. to 3 p.m.
Caltrans expects delays to last no more than 10 minutes.
This traffic switch is part of constructing a new roundabout and to improve safety on both state routes in the area.
The $3.3 million project and is expected to be completed this summer.
For traffic updates on other state highways in Santa Barbara County, motorists can call Caltrans District 5 Public Affairs at (805) 549-3318 or visit the project website at: http://www.dot.ca.gov/dist05/projects/SB154@246/index.htm