New London CT
Amtrak's Montrealer briefly diverged here from the Northeast Corridor main line.
An interruption of service east to Boston, and the removal of a segment of track considered unneeded at the time, necessitated some creative detouring with a backup move for a few years.
At one time, two different Amtrak trains operated into Montreal, operating into two different stations.
The introduction of the Capitol Limited involving two different railroads, required construction of a new connecting track east of the station.
New Castle PA
The switch of the Broadway Limited to the Baltimore & Ohio route west of Pittsburgh, resulted in a new connecting track from the former Pennsylvania Railroad.