A few months ago I thumbed through a book in a book store that described a cycling route through California. I looked up the section through San Diego, and it was clear they followed the local cycling map, and a route I would not recommend. For example, they chose a route along an old dilapidated bike path, rather than a parallel route a few blocks away along the ocean, with spectacular views (and light/easy traffic, though narrow lanes), or a route in between along a 35 mph arterial with wide outside lanes.