Unfortunately the powers-that-be who are developing former MCAS El Toro have closed the old Perimeter Road to bicycles. This road runs along the south and east sides of the base. This eliminates the connection from Marine Way to Astor and Fairbanks in the East Irvine Industrial Complex.
Riders can still enter the area on Marine Way off Sand Canyon, but will have to turn left up either Ridge Valley or Sky Hawk/Bosque to Irvine Blvd. Bummer, especially for those of us who live in Lake Forest!