i dont know where you were waiting on 395 (i.e. just near the exit you wanted or near Pentagon City).  i think some directions say take penn ave exit, some say 6th st. SE.  but if 395 wasnt backed up to say Pentgon City.  once you get over the river just try to take any exit, go a couple of blocks north to independence, turn right (east) and take it to the stadium.   famliarize yourself with the grid system though in case you get lost.

Yeah, I was on 395 from Pentagon City to the Stadium exit.  Towards the exit itself 395 opened up except for the left lane...making it apparent that it was satdium traffic at that point.  

I've been fearful of getting off anywhere elese, thinking that traffic on the streets leading to RFK would be even worse.....maybe not?