I do 80-120 "miles" a week, often times 40-50 of those are on a trainer doing a set workout at midnight (no 'junk' miles on the trainer). The rest of the miles are on the SART and sometimes I'll hit up Santiago canyon, back bay, or yorba linda hills. I do a self supported century about once a month, as the wife can handle things while I go play for 6 hours on a weekend.

I do 6 weeks of the Time Crunched Cyclist plan every 3 months or so (6 weeks on, 6 weeks off) and that helps build my fitness without having tons of time to live on a bicycle. The book gives a very clear prescription for the workouts, no guesswork involved assuming you have a powermeter.