Easiest way to knock down the noise is to re-direct it,stop by an auto part's and get a curved exhaust tip that lock's on with set screw's.Turn it down and the sound changes with no other effect's like milage,starting.I got out of a few noise ticket's doing that with straights.

 

Great Idea!

 

As you move west, you'll find that these rest stops of which you speak are non-existent. I thought they were a great idea when I saw them on the highways back east, but we really don't have them here. Most exits (at least those near a town) have a quick on/off gas station, but you do have to get off the freeway to get to them.