F40, from Attleboro take 123 west into Pawtucket. At the 1st set of lights, take a left and go straight about 1 or 2 miles to the end.
Or, from Rte.1 in South Attleboro take Brown Street as far as you can (after entering Pawtucket the road gets narrow and ends at a 3 way stop). At the end of the road, take a right, down the hill past the water treatment plant. At this stop sign turn right and about 500 feet after the Dunkin Donuts you will come to 2 grade crossings. The first is the East Providence Line which is the line that crosses directly over the NEC just south of S.Attleboro station after passing by State Line Scrap Co. The second crossing is the main-line between Worcester & Providence as Dave mentioned.
An interesting place to chase them is when the local goes toward E. Providence......push-pull with several crossings to protect and customers to serve. (Take RTe1 south into Pawtucket, and take a left at the RR crossing. I forget the name of the street, but it follows the line for a couple miles, crossing back and forth from oe side to the other.