Runaround track on siding

Is it realistic to have a runaround track (it is about 17in long) leading towards a siding? I have a 17in runaround track and spent a lot of time playing around with keeping it or not. Part of the logic for having it is a “hot train” needs to get something and shoot back on the mainline.

TIA!

Lee

There are situations like at a town or a spot with several industries to serve where you might have a double-ended siding off a mainline, long enough for an entire train can pull in there and clear the mainline for other trains. Off of that siding, if there are both trailing and facing point spur tracks, you could have another siding for locomotvies to use as a run-around so they can serve both the facing point and trailing point spurs without having to go back on the mainline to do the run-around.

I believe John Armstrong “Track Planning for Realistic Operation” had some diagrams etc. about this.

Double ended sidings are used to drop or pickup cars in either direction. Or to not disturb a car that is still being unloaded.