My commute, using my shortest route, is 13.5 miles each way. I didn't think I could do it, due to traffic and other logistics. I did a trial ride of my route on Martin Luther King Day 2011 (today is my one year commuting anniversary). The trial ride was useful in many ways. I quickly discovered that my backpack-bungee cord-rack setup wouldn't keep the backpack securely on the rack. I also discovered that my morning commute was faster than my evening commute, due to traffic patterns. Now that I am used to commuting to work, I vary my morning route to keep things interesting. My favorite route is about 20 miles, and allows me to watch the sun rise over the lake. I have significantly more energy when I get to work on a day that I ride my bike than on a day that I drive the steel cage.

I'd suggest doing a trial route on a day off. Do the ride as though it would be a work day, with any bags you plan to carry being loaded.

Good luck, and enjoy the ride!