The hand ends when one player “goes out” by discarding their last card. You may not go out on your first turn!
You may only go out if these conditions are met:
1. You have at least one train of at least five cars (plus a Loco, of course) and one train of at least four cars.
2. All your trains are scoring. You cannot go out if you have any trains with only one or two cars!
3. Having met the above requirements, you discard your last card. This must be a regular discard; if you discard a Disaster or Turntable, it does not have its normal game effect.
4. All players then score their points. The player who went out scores an additional +10 points.