The train is the Acela Express from Boston to Washington D.C. (it is moving from right to left, looking at the photo.) It is Amtrak's high speed train. It's top speed is 150mph.

"The Amtrak Old Saybrook – Old Lyme Bridge is the last crossing of the Connecticut River before it reaches Long Island Sound. It is a Truss bridge with a bascule span, allowing boat traffic to go through. Its tracks are owned by Amtrak and used by trains on their Northeast Corridor and Shore Line East high-speed rail lines. It can be seen from the Raymond E. Baldwin Bridge (Interstate 95 and U.S. Route 1), as well as from various points on Route 154.

Also known as Connecticut River Railroad Bridge and as Connecticut River Bridge, it was built in 1907. It was determined eligible for listing on the National Register of Historic Places in 1987, but it was not finally listed due to owner objection, with decision noted in National Register reference number #87002125" Wikipedia