Travelling by subway can be quite an adventure (冒险). It's hard to find your way in the space filled people. People run quickly to get a seat. And be (care) of that girl who is holding a cup of hot coffee.
To deal with these problems, all (country) have made rules for subways to follow. The most common one is no eating drinking on the subway. Many cities in the world have this rule.
New York City has asked passengers (take) off the backpacks on the subway. Also, passengers are told not to open (they) legs wide enough to take up two or even three seats.
There are some (interest) rules, too. Paris, France (suggest) that passengers shouldn't play music too loud through headphones or stare (盯着) at women for long time. New Delhi, the capital of India has stopped drunk people from (take) the subway since May, 2013.
Whether your city has the same rules or not, it's always good to behave (举止) well on the subways.