I'm going to add that, depending on the day, you should allow up to 3 hours for the trip from Richmond to the Beltway around DC. I know it's only 90 miles, but the traffic around here is unbelievable, second only to LA traffic. And this also applies to weekends. I can't explain it….noone can. It's a crap shoot as to which day and what time it's going to be the worst, but Thursdays and Fridays are the absolute worst. Most people come OUT of DC in the evening, and go IN in the morning, but it's pretty bad both ways. If it's raining, add up to 1 hour to the travel time from Richmond. Again, don't ask. Around here the formula seems to be "Instant idiot driver, just add water..." The southwest 1/4 of the beltway (inner loop) is worse in the mornings and the outer loop is worse in the mornings, but when you near Rte 50, Tysons and the Dulles Toll Road, it sucks in BOTH directions. Once you get on the Toll Road (Dulles HOV lanes), however, you are home free. The Toll Road (non HOV) isn't terrible either. 95 North and the beltway are going to be your biggest obstacles. Agian, time dependant. You're better off doing it on a weekend (Sunday at 3am is the best time, I've found...).
On the lighter side of things, these are some general driving guidelines that will make your travel as fast as possible:
Watch out for cars with MD tags, they REALLY can't drive. Make sure you stay in the left lane and drive as slow as possible, that's apparently what everyone ELSE does...and you want to fit right in... If their turn signal is NOT blinking, that means they are about to change lanes. If their right signal is on, they are going left and vice versa. If you want to change lanes, try the freeway on ramps and off ramps and the shoulder of the road, they are really good for going around long lanes of traffic and cutting people off who've been waiting patiently in line. If you see a stalled car or a car with a flat within 500ft of the highway, slow down to about 15 and take a really long look. Make sure when you slow down, and this is really important, that you almost lock your brakes or else you won't cause enough accidents behind you. The more accidents you cause BEHIND you, the more clear the road will be for you since you've, in essence, eliminated the traffic to contend with. When the lane in front of you is clear, floor it and drive as fast as possible until you see brake lights, then slam on the brakes. Lather, rinse, repeat.
I think that covers everything. I've been here for 10 years and I think I've got it all figured out.