Delhi Metro is generally considered one of the finest public transit systems in India. However it has evolved its own cultural idiosyncrasies. Spitting within the Metro is punishable by a fine. There is no spitting within the Delhi Metro. Elsewhere in India, people spit everywhere. Toilets in the metro are clean and not free. Its incredible how well maintained they are compared to toilets in urban India as a whole. Rural India does not have access to toilets, which is an occasional cause for rapes against women relieving themselves in fields. You are not allowed to eat within the Metro. But there are enough eating places within the Metro system that enable you to have a snack.
Oh and there are no dustbins except next to these snack kiosks or restaurants. Like most of India, women have a separate reserved compartment exclusively for them. This is enforced and reinforced by both security guards and cameras. Security guards in the Metro do one more job, telling people to stay within a line and not push others. Pushing is endemic in rush hours as the Metro system basically resembles something worse than cattle carriages. The jam packed train compartments have barely any space to breathe or move. Still it is considered better than Mumbai railways in rush hour. Despite the fact that the windows and doors are closed, may people still like to stay within the entrance doors of the train compartment. This causes needless pushing and aggravation when people have to get down or get up on the train. Once in a while it even leads to loud arguments.
Overall Delhi Metro is a cultural paradox, how people can switch to being relatively more polite within a transit system and rude just meters outside. As countries become prosperous and populations get educated and exposed to global norms, culture too evolves. I love my Delhi Metro. It has changed the life of many people in working living and commuting in the city.