CA 126 does it, the highway have a center median strip from Santa Paula to I-5?
I have noticed that Caltrans are improving this highway with traffic circles in its intersections in it's plan.
Scott C. Presnal
Morro Bay, CA
Mod note: Slightly changed thread title. –roadfro
The last time I drove on 126 (circa 2011) it was mostly a 5-lane facility with a bidirectional center turn lane east of the Santa Paula freeway terminus. At that time I didn't see any roundabouts or construction for such in progress -- although I wouldn't be surprised to see one installed at the CA 23 junction in Fillmore.
Here's the project in question:
http://www.dot.ca.gov/dist07/travel/projects/126/
It is still 5 lanes and undivided between Fillmore and Santa Paula, and even with rumble strips in the center lane, it's a very dangerous stretch of road. There's a lot of ag traffic, but also a lot of general traffic cutting through.