No luck here. I'm working as well.

The only part of that route I'd worry about is rt.144 & rt.40 on through Frederick.
Super aggressive and trafficky in there. Barry might know better.

I mapped this about 9 mos. ago.
http://www.bikely.com/maps/bike-path/133627
HOWEVER, I haven't ridden it yet so take it as you wish.
The route drops down to avoid Frederick. Might be helpful.

EDIT: I just realized that this is probably the western route of the DC rand's Spiral Staircase ride. NR rode that one.