Why do longer passenger train take longer to load/unload, each carriage has a door onto the platform, ten carriages should fill as quick as one. In real life in uk mainline trains are only stopped for a couple of mins at through stations.
This seems to be one of the factors influencing train spacing problems on my mainline. The train with the biggest spacing between trains has more passengers to pick up. This takes longer allowing the train behind to catch up. It has fewer passengers to pick up, so catches up more each time.
Ive increased the block spacing on my lines but it only helps a bit, not uncommon fot 6 trains to be heading north with none south bound on long lines.