Ballston, VA to Reagan National Airport, VA: 3
Starting from MaryMount University, Ballston, Arlington VA head West on Custis trail until you hit the W & OD trail. Head East. At some point you can either continue on the W&OD or take a detour on the Four Mile Run. We took the detour. Close to Shirlington you can go under the newly built underpass below I395 to eventually join the Mt. Vernon Trail. Head North to Rosslyn. Join the Custis Trail. Head west until Marymount university. This was late in the evening and was a nice ride.