The problem with bicycling in San Diego is geographic more than infrastructure. If you live and work in the same area, usually bicycling is fine. But the entire city and surrounding areas are segmented off by large mesas, hills, and mountains, with the connections between the areas mostly done by freeway or 50+ mph access roads. So if you live and work in Mira Mesa, fine. If you live and work in Clairemont, fine. But if you live in Clairemont and work in Mira Mesa, forget it.