Can't speak of the trails in the states you mentioned, but I've ridden many of the rail trails throughout PA, and would highly recommend them if you might think of venturing there. I've ridden several in Pa, including the North and South Youghiogheny River Trail (listed under Great Allegheny Passage)-good ride with good mileage. Check out the Rails to Trails site (
http://www.traillink.com/home.aspx ) - if you just put in the state, it will pull up the trails in that state. If other states are keeping theirs up as well as PA does, should be fine for a road bike.