Cold Creek and its Pusher Wagon

Can anyone enlighten me as the need to add a pusher wagon to a consist going over a crossing as instructed in the Cold Creek Intro Session?

What's its purpose and where in the consist would it go?

In your hoped for replies please bear in mind that I'm from the other side of the pond as they say.

Many thanks in advance.
From my understanding the car would go on the head end of the train, with the engine on the rear. This allows the conductor to safely guide the engineer into the correct siding over long distances. A caboose will serve the purpose just as well, but have an interior to maintain, so a "flat car" is cheaper.
It's for both of the already mentioned things.
1, it's a place for the conductor to stand so he doesn't have to grip the handrails/ladders on the car, which would wear him out and he might fall because of that.
2, it's so that there can be lights, ditch lights, a bell, and a horn at an RR crossing.