You choose any time to start (mutually agreed upon)
You can choose any row you want. The chance (skill?) comes into play in that people can get up from those seats and new people can come in. That's why you have to choose an end station. It probably wouldn't be very fun for just one stop.
In other words, you pick immediately once the game starts. Look around to see which row you think has the best chance to develop into something good by the time you reach the designated station.
It seems you don't have any control over the hand, no control over the evaluation, and there is no betting either.
Something more akin to bingo, where you call out when a winning combination is found, would be a lot more engaging.
Or maybe keep your chosen hand a secret, so you can do the normal betting/bluffing/folding of Poker? With the added fun that your hand might change over the course of the game.
- to stand in a specific place in order to (subtly) direct other passengers into a specific section of the car, or
- to take a seat yourself and give it up to an elderly person later on, in an attempt to gain an extra ace ;)
Could you ask a friend/plant to come to a particular station at some time and sit in a specific seat to aid/hinder a set? Gesturing to someone a specific seat is open? How about outright asking someone if they'd be willing to sit in a particular spot?