I commute to work 5 days a week 5.5 mi. each way. I also ride and do errands on Sat./Sun. My riding is 100% urban - streets. I ride to work in the afternoon and get off work at 10:30 P.M. At night I ride more cautiously than in daytime. I'm always cautious but have a higher level of awareness at night. Friday nights call for even more caution due to all the people at restaurants and night spots. For the most part motorists here in Cleveland have been pretty respectful toward me.
I ride a fixed gear bike mostly and I have a Kona rigid MTB that I run with wider tires and full fenders for bad weather (which we get a lot of).
I had started riding mostly for fun but but take it pretty serious now. Sometimes when I'm driving I find myself wishing I were on my bike. It's a great way to live - I try to encourage more people to start biking. I hope to commute until I retire.