Email the District 5 Traffic engineer and ask for documentation that standard traffic control devices have been previously evaluated.
Remind him (or her) that:
"Along the length of the highway, serious and enthusiastic road cyclists make good use of this section of the Pacific Coast Bike Route. Both day trips and overnight tours are common, some as part of organized supported rides and other independent riders alone or in small groups."
I c&p that from the Caltrans Corridor Management Plan.