Instead passengers are expected to validate tickets in a special stamping machine before entering the train.
For instance, the Plusbus scheme in the United Kingdom offers bus travel on an integrated ticket for an additional fee.
Some systems (Amtrak, for instance) have two-part tickets that permit the passenger to retain a cancelled ticket stub; others (the New Jersey Transit and Massachusetts Bay Transportation Authority commuter rail systems, for instance) do not.
Until 2019, Eurostar had an agreement with Deutsche Bahn that allowed passengers to travel on a through-ticket by train from the UK via Brussels to Germany.
In India, an SMS sent by the Indian Railways, along with a valid proof of identity is considered equivalent to a ticket.