Significance When cells heal a wound or invade a new area, they coordinate their motion. Coordination is often studied by looking at what happens after pairs of cells collide. Postcollision, cells often exhibit contact inhibition of locomotion—they turn around and crawl away from the point where they touched. Past knowledge of repolarization on contact comes from studies on flat surfaces, unlike cells in the body, which crawl along fibers. We discover that cells on single fibers walk past one another, but cells in contact with multiple fibers stick to one another and move as pairs. This outcome changes to walk past after cell division. Our experiments and models reveal how the environment regulates cell–cell coordination after contact.