Vintage photos show how the subway evolved and how it's still the same in some ways. The world today looks a lot different than it did when the New York City subway first opened in 1904 ...

One reason to visit New York’s Transit Museum is it not only reminds you of how impressive an endeavour the city’s subway (opened 1904) was but what an achievement all underground railways are.

About 85 percent of New York City’s subway system still operates with this analog signal system. The outdated equipment is no longer manufactured and has to be manually operated, around the clock.