is a person who has as a hobby
the study of metro
(subway, underground) systems.
Such people may indulge their hobbies by
- travelling and visiting as many metro systems as they can;
- attempting to find out about and/or visit hidden nooks and crannies of a metro system;
- learning about the technology, architecture, and history of various metro systems;
- collecting material related to metro systems, such as maps, plans, transfers, tickets, and the like, often from many cities around the world;
- publicizing their metro systems (some metrophile websites contain more information about the system than the transit company's own);
- designing expanded metro networks for various cities;
- discussing their findings with others;
- and in general writing, learning, teaching, photographing, and thinking about metros.
Some metrophiles even manage to attract attention, approval, help, and even employment from transit companies.
One metrophile, a mentally ill New Yorker named Darius McCollum, impersonated a range of New York City subway personnel for some time; he was so technically proficient at driving trains, helping repair crews, fixing trains, and even dealing with emergency situations, that he served with some distinction (and a certain amount of complicity from actual personnel). Unfortunately, this was quite illegal and he was repeatedly arrested and, despite a plea to have him treated for Asperger's Syndrome, was finally imprisoned. Harper's Magazine published an article on him in May 2002.