They can be configured as racing, dueling, or Möbius loop roller coasters.
Some dual-track coasters operate only one track side at a time, including Rolling Thunder and Colossus.
Racing roller coaster: consists of two separate roller coasters that travel along parallel or mirrored tracks to simulate a race between the trains.
The coaster trains travel along tracks just a few feet apart from one another.
In less common configurations, a Möbius loop coaster train travels the entire length of the track before returning, such as with Twisted Colossus and West Coast Racers at Six Flags Magic Mountain.