I brought my wife's car out to Falls Church to get the A/C serviced, then rode to my Arlington, VA office from there. The WO&D and Custis trails are ill-signed, but it is amazing to be able to ride for perhaps 6 miles (10) km without a single stoplight or stop sign. It was also amazing how much more of a workout a trip can be if one is not coming to a stop every few blocks.
Paul
(who thinks he finally labyrinthine Northern Virginia trail system worked out, but still generally prefers roads.)