Mimitabby, I commute ALOT through the mean streets of Washington, DC, and I LOVE IT!

It sounds like you are doing everything right. I would just add that you may be able to find a quieter and more pleasant route. It may not be the most direct, but I've found that having several routes from which to choose, it keeps things interesting.

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In my area, the Washington Area Bicyclists Association (www.waba.org) conducts effective bicycling courses. I have not been to one since I'm very comfortable in traffic, but it would probably do me good anyways. If you look at WABA's website, you might find out if there are similar offerings in your area.

Have fun!