The A-Train Construction Set
was released in 1992, allowing you to create your own maps or edit existing ones.
Some historical notes, from the manual:
A-Train was created in Japan by Artdink, and is the first game that Maxis has published that was developed outside of the company. (We have huge egos and think we're pretty good game designers, so if we publish someone else's game, it means we're really impressed.)
This game is actually Artdink's third complete version of A-Train, which was released as Take the A-Train III in Japan.
The first version of A-Train was released in Japan in April 1986 for the Fujitsu FM-series computer. It was later available for all the major home computers in Japan.
A-Train II was released in Japan in July 1988, and was published in the U.S. by Seika Corp. under the name Railroad Empire.
Take the A-Train III was first released in Japan in December 1990 and since then has been a consistent top-ten seller, winning the Best Simulation of the Year Award from Login magazine (well, actually it tied for first with SimCity), and winning reader polls as their favorite simulation game.
Take the A-Train III, under the name A-Train (we dropped the 3 since there was never a 1 or 2 released in this country), is now published by Maxis.
From the manual:
Depending on the map, and what you've had for dinner, there are some interesting items in the skies. During the night of December 24, Santa Claus is flying across the map. UFOs may appear on summer nights, and there are firework shows on Saturday nights in August at the amusement parks.