Mark Byrnes is a senior associate editor at CityLab who writes about design and architecture.
20 mass transit maps worthy of hanging on your wall
Mass transit maps can be a big part of the visual culture of cities. The more iconic the map, the more likely it is to be turned into a t-shirt, an umbrella, even a shower curtain. Here's a look at 20 different subway system maps that serve as a window into the culture of their respective cities.