From where you are you need to come down to the DC beltway, and take it south. Get off at exit 7a (Rt. 5/Branch Ave). Take 5 south. It will become Rt. 301. Just follow 301 south until you get to Rt. 234. Make a left onto 234 and it will be on your right after about 10 miles or so. You'll probably be on 5/301 for about 30 miles after you get off the beltway. Here is a link for MIR it should give you some info. Also jrock is right about the cops. I'd take it easy as you start getting closer and closer.