Caltrans began a project to resurface about 35 miles of State Route 166 from west of Carrizo Canyon Bridge to Cuyama Canyon Bridge Thursday.
During the resurfacing project, drivers will encounter one-way reversing traffic throughout the week.
The delays will be Monday through Thursday from 8 a.m. to 4 p.m. and from 8 a.m. to 2 p.m. on Fridays. Crews will be working overnight Sunday from 7 p.m. to about 11:55 p.m. and Monday through Thursday from 6 p.m. until about 6 a.m. the following morning.
Caltrans said drivers can expect 15-minute delays because of the construction.
CalPortland Construction of Santa Maria is working on the $5 million project that should be completed by November.