You cannot pass into the waiting room of the depot till you have secured your ticket, and you cannot pass from its only exit till the train is at its threshold to receive you. Once on board, the train will not start till your ticket has been examined--till every passenger's ticket has been inspected.
This is chiefly for your own good. If by any possibility you have managed to take the wrong train, you will be handed over to a polite official who will take you whither you belong and bestow you with many an affable bow.
Your ticket will be inspected every now and then along the route, and when it is time to change cars you will know it. You are in the hands of officials who zealously study your welfare and your interest, instead of turning their talents to the invention of new methods of discommoding and snubbing you, as is very often the main employment of that exceedingly self-satisfied monarch, the railroad conductor of America.