To come together or come up against with force
To come into violent contact
To come into conflict
One headed for her, and she turned to run, only to collide with a large figure at her back.
The chorus of the song goes on like this I close my eyes/And try to hide/But wait when these dreams collide.
It also provides coverage when members collide with an object other than another vehicle.
Duos sometimes play just as a pair and sometimes have backing bands, but two heads are better than one when complementary musical visions collide.