What day of the week, and what time of day? Last year, we hit DC around 10:30 on an August saturday and it was starting to back up, and stayed that way all day.
This was on Memorial Day (Monday). We left the DC area around 10:00 am. We didn't pick up I-95 until south of 495, but according to the WTOP website (which we checked before leaving), traffic was moving on all the major roads. We did see more traffic in the opposite direction (northbound), esp as we got closer to Richmond.