People have come up with a number of variants to suit their style of play.
People have asked whether, if On the Underground was published again today, any changes would be made to the rules. The answer is that serious consideration would be given to tweaking the start and end of the game in the following way:
All players start with zero points. However, on the first round, the start player places only two pieces of track, other players place three and the last player plays four. In subsequent rounds players always play four pieces of track.
When the draw pile has no cards, then the Passenger is not removed from the board, and play continues with players building track and moving the Passenger. If there are no destinations for the Passenger to move to, then the Passenger does not move. When the next to play is the start player, the game ends.
Fans of I'm Sorry I Haven't a Clue will know that the game should end when the Passenger reaches Mornington Crescent. This variant allows that to happen:
Before playing, remove the Mornington Crescent card from the deck and shuffle it into the bottom five cards. Play On the Underground as normal - however, instead of stopping the Passenger moving when the draw deck has been left without any cards, stop the Passenger when he reaches Mornington Crescent.
For younger or inexperienced players, who find it hard to visualise the movement, it is possible to play a simplified version in which the Passenger doesn't have to choose between destinations. This variant also shortens the game somewhat:
Split the deck into one deck with express destinations and one with normal destinations. Instead of drawing four destination cards, draw one card from the express deck and one card from the normal deck. When all the express stations have been visited, continue the game with the Passenger visiting only normal stations until each player has had an equal number of turns; then the game ends.