Wow, thanks for all the responses! Unfortunately I don't think commuting by bike will be an option...It's 23-ish miles each way, and for those of you familiar with MD, I'll be commuting from Laurel to Rockville. The DC exurbs are clogged with traffic.

Part of my problem is that I really do just need to get more comfortable around traffic. I'm still new with all this and get rattled when a van gives me a foot clearance at 40 mph. Apparently I also need to get to know my own area more! Sarah -- I just looked up Columbia Gateway Drive on a map, so people just circle through that that as a training ride? Also, if you don't mind sharing details I'd love to know what your favorite post-work route is (I assume its through Patuxent State Park?). We're more in Laurel than Columbia, but of course we could drive for 15 minutes to get to real Columbia for the start of our post-work rides.