| 1 | Ideal journey |
| 2 | Bus B delayed by traffic congestion |
| 3 | B delayed by picking up passengers meant for C |
| 4 | C is early as B has picked up its passengers |
| 5 | Bus-bunching |
In public transport, bus bunching, clumping, convoying, piggybacking or platooning is a phenomenon whereby two or more transit vehicles (such as buses or trains) that were scheduled at regular intervals along a common route instead bunch together and form a platoon. This occurs when leading vehicles are unable to keep their schedule and fall behind to such an extent that trailing vehicles catch up to them.