Originally Posted by Nowhereman1280
.. Bunching occurs like a traffic jam when you have too many individual vehicles on one ROW. Trains eliminate this by linking all the individual vehicles into a single train thus reducing bunching.
Trains don't eliminate bunching. No one who has lived and taken commuter-hour trains in a major city would ever claim than trains eliminate bunching with a straight face.
Bunching occurs when events outside the control of the scheduling agency cause trips to take longer than scheduled, causing one train to slow down and vehicles behind it to "catch up" and cluster near it. Thus, there is a longer gap between the last non-delayed vehicle and the first delayed vehicle, followed by the delayed vehicle(s) and vehicles scheduled closest after it.
This happens with trains when loading/unloading takes too long, or when mechanical issues cause delays.
The reason bunching is more common and worse with buses is that that buses also have loading/unloading and mechanical delayes, PLUS, they have delays induced by traffic signals and car traffic, since they aren't grade-separated.
This Chinese system is (mostly) similar to trains, in that it reduces the traffic effect buses experience, so bunching would be most similar to that experienced by trains.