That sounds identical to what the Calgary busses do? You'd still need coordination between the busses to know when the loaded bus "wants" the empty one to overtake it.

The difference is that it was a one-and-done thing rather than leapfrogging back and forth as it sounds like `theluketaylor` was describing.

And yes, the drivers would coordinate. (I've sometimes seen it done with a brief honk for attention followed by a hand wave.)

Why does the loaded bus’ preference matter? If you see a bus stopped ahead of you with the same route number and nobody requested that stop then just continue.

The driver in the front sticks his hand out the window and waves to the one in the back