From Camarillo, you can get to Bradley Rd and the Somis area with just a very brief time on the 118. Go to the Calleguas Creek bike path (you're only on it for a mile or two), head north on it, turn left on Upland where the bike path ends, then right on Lewis, to North St. in Somis. That ends at the 118, turn left onto 118, then take the first right (<100 yds), right after the Somis Nut House, onto Bradley Rd. I live in Newbury Park and commute to work in Camarillo. My route is here:
https://www.strava.com/activities/1398520888. I come down Potrero behind CSUCI early in the AM on my way to work. I wouldn't recommend going up it except at low traffic times of day -- it's steep and narrow and cars really aren't happy you're there. I would also recommend Las Posas to PCH, maybe up Encinal, go right at the top where the road ends, then left at the next stop sign, which is Mulholland. That will take you back to PCH.