I used to drive it all the time when I lived in Ventura... but that was 10 years ago. If I recall, there was a short stretch near Encino that dead-ended at a reservoir.
The stretch that runs through the Santa Monicas was great bike country. Some gravelly/sandy parts to watch out for that made it more of a cruise than a knee-scraper.
Again, my experience is 10 yrs old, so take it with a grain of salt. TWN and other locals have current info.
Cheers!
Griff in the Great White North