[remarkEon]

Controlling which doors open as dependent on how full the route is and how bunched the buses are is just going to confuse passengers and make for a horrible rider experience. I sympathize with the idea though, as veteran riders know to move to the back as the bus nears your stop.

[kingosticks]

I mentioned it as it's what sometimes happens in London when the bus is very crowded. They do it because at the point it makes sense the rider experience is already horrible. For most buses it is front doors for getting on and rear (middle) for off. It's already independently controlled so it is not extra complication. But I do appreciate other places don't have the same system.