Something I wish Metro Systems did - Air (Transition) Conditioning
This is primarily an underground metro thing. But I feel like going straight from an Air Conditioned space to the outside ruins the outside place because your body goes into crisis mode trying to adapt itself to hot and humid climates. Instead, if metro systems, and by extension any other large air conditioned public space (such as airports), had a section next to their entrances and exits that was weakly air conditioned, it could serve as a natural buffer allowing people's bodies to adapt themselves to the outside.
This is something I noticed when I was in Kolkata. The East West Metro system is fully air conditioned to the entrances. However, exiting at say, Sealdah station directly into 2pm sun and 70% humidity is not a fun experience. However, this is something that is better with the original Blue Line (alongwith a bunch of quality of life things). Because the stations are weakly air conditioned, you only get the full effect of the AC inside the train itself which is the most crowded place and thus, where AC is needed most. Having an approach like this could also save a lot on energy, especially with larger areas.
What do you guys think?