Subway

The Subway is a rabbit hole transportation object that will be included in The Sims 3: Late Night expansion pack. The existence of subways was confirmed during a Grant Rodiek "twitterview" on July 29, 2010. Subways will exist as a free, nearly-instantaneous form of transportation, and the player will be able to determine the destination of Sims using the subway. Sims might also be mugged on the subway. It was also confirmed that it can be placed on residential and community lots. It may not be possible to view Sims while they are in it. When your sim gets robbed (formerly mugged) they get a "hurt" moodlet.

The Urbz: Sims in the City
Subways were featured in The Urbz: Sims in the City as a form of transportation. They could not be fully interacted with although the Central Station neighborhood did represent a subway station.