I live in Garrett Park - a small town near Kensington - and work at the northern edge of Old Town. When I bike, I use the sidewalk of Connecticut Ave to the Capital Crescent and Mt Vernon trails, crossing at the Key bridge. (My wife works on capitol hill, but I almost never actually get into the District except when I'm biking.)

When I drive, I come over the Legion Bridge and down the GW. In August or during off-peak hours, it's about a 30 minute drive each way.

-jk