My route takes me through neighborhoods for the first 3 or 4 miles. After that I am on 4-lane main roads with bike lanes the rest of the way in. The return trip in the evening is the reverse. I have never been hit though I have had several close calls. I've learned to keep my eyes open and give way to those big cars!
I started commuting by bicycle 5.6 miles to the nearest bus stop in October of 2001, shortly after moving to Arizona from Montana. About 6 months later I decided to try the full commute to work one day per week. That was a chore but I kept at it. I eventually started doing 3 days per week and then 5 in early 2003. I bought a new road bike in April 2004 and have started riding on Saturday mornings as well. I now use my bike as my main form of transportation. I don't own a car, though my wife does. I just got back from riding in the 2004 Seattle to Portland Bicycle Classic (206 miles in 2 days) and am looking for more long organized rides. I'll be 50 next May and have never been in better shape.
My only accident while commuting happened in January 2004 on the way home. I was only about a mile from home on an unlighted street when I ran into a pile of crushed granite left in the street by a landscaper. I had my light on and was doing everything right. The landscaper hadn't bothered to use any lights to mark the pile. I never saw it. I hit going 12-14 mph and came off the bike forward. I never touched the pile, just landed on the black-top on the other side and slid on my chin and chest. I'm sure glad I was wearing a helmet or I probably would have broken my nose and glasses. I did go to the hospital and was off my bike for 6 weeks while bruises on my legs and ribs healed.