In the example puzzle below, the blue and yellow cars need to create two green cars. Merging would create only one, so they need to cross each other before heading to their goal:
To create a Crasher, first connect the sources of the two cars. Add two exits from this track, one on either side of the place where the cars will meet. Then you just have to make sure that the exits are 'inactive' - it should look as though the two cars will meet and then crash into the stations again.
This is a quick and easy solution even when the two stations are right next to each other:
And there's an even more elegant solution to crash two cars that come from the same station:
The last form I'd like to discuss is the Multi-Loop; unlike the rest of the forms so far, its only purpose is to cause delays.
Next: The Multi-Loop