As for the 495 question?

Yeah, there are alternatives other than 301, which will take you right into Waldorf, Md and a bigger mess than what you are trying to avoid...

For those of you who must take 95 North (if 81 is not an option) then take 17 West in Fredrickesburg. (This road actually run northwest). About 30 miles up 17 you'll pass Warrenton and then a few more miles (about 8) take a left on Rt. 15 North. Take 15 to Fredrich, Md., then 70 east to 695 (Baltimore's beltway) take inner loop to 95 North.

This will save you at least an hour and maybe 2, depending on time of day...

Bobert