To get out of traffic. I think the easiest trails are the Custis Trail that follows the orange line into Virginia and the [Blanked on name] that runs into Alexandria. Four Mile Run connects these two opens up more neighborhoods in Arlington. These keep you out of traffice for nearly all of your commute. The Cresent trail coming down from Maryland and Bethesda is nice but darker at night with less foot traffic through some wooded areas.
