What follows the intertracking of Raritan River?

The correct choice, trailing, refers to the movement of trains in relation to an interlocked track section where the direction of approach is behind the operating locomotive, typically indicating that the train will continue on its path without taking a diverging route. In the context of intertrack operations along the Raritan River, trailing movements are typically aligned with the way trains pass through junctions or connections where one line merges into another, taking into account aspects like signals and switch positions.

The other answers do not align as accurately with the context of train operations following intertracking. Leading suggests a situation where the train is preceding another, which is significant in specific operational scenarios but does not directly relate to the intertracking procedure. Switching focuses on the action of changing tracks or route configurations, which is part of the intertracking process but does not encapsulate the nature of movement itself. Connecting might imply linking two tracks or lines, but it does not describe the specific directional movement associated with trailing or leading in the context of intertrack operations.