Originally Posted by force10

If you click on the section of the map that where an obstruction exists, a window appears detailing the nature of the obstruction and mile marker.

To answer your earlier question, the D&R is a good alternative to the D&L between Frenchtown and Lamberville (as far as I went back in August). You would want to cross the bridge in Riegelsville and head south along the river in NJ to Frenchtown in order to do so.