[barry-cotter]

Because things which are designed to be good at one thing will not be as good at other things. There's only so much rail network and given a conflict either freight is a priority or passengers are. You can't have two number 1 priorities.

[chiph]

I'm pretty impressed with India opening dedicated freight corridors. It's double-track that is optimized for longer, heavier freight trains. It seems obvious that the different operational patterns of freight and passenger rail means they each should have their own tracks. The only thing they did "wrong" IMO was to have level crossings where cars & trucks can get hit by the trains.

https://www.youtube.com/watch?v=pd6EW9QsRto