If you travel through Rosslyn, via the station, one of the many busses that come through or may be even use it as a pick-up point outside the city, be prepared for a few traffic changes that will begin this weekend:
Starting Saturday, North Moore Street will become a one-way street heading south toward Wilson Boulevard. As a result, taxi stands and bus stops will be relocated to other parts of North Moore Street. Also, passenger pickup and drop-off will be prohibited on North Moore Street — it will only be allowed on the Fort Myer Drive side of the station.
The modified traffic pattern is to account for construction on the new Metro entrance and is likely to take a few years.