Multi tracking dedicated platforms and trains will have to be in place ..
The open windows hampers the train acceleration / deceleration and MPS !
Hence IR is required to find balance between raising fares and subsidising AC travels against 2S .. they can always do it by pushing more people in the coach and making the facilities basic ..
Regional...
more... Namoh trains will be good example ..
VBs can remain premium
Intercities can remain Non premium but fast connection offering with mix or subsidised travel ..
VMs for shorter regional routes
VBS for longer route premium travel
AMBs for longer route subsidised travel