Trains, Buses, People: An Opinionated Atlas of U.S. Transit, a new release from Island Press, is undoubtedly a book for transit nerds. But everyone else could learn a little something from it, too. In just a few quick visuals, it's able to distill why transit use is common in some big cities in the U.S., while in others, people are chained to their cars.

The density maps, which we first spotted over on CityLab, highlight where the most people live and are employed in major U.S. cities, overlaying information about how accessible frequent rail and/or bus service is in that area. The combined data show a realistic picture of how accessible certain parts of a city are, illuminating which U.S. cities, and which of their neighborhoods, are easiest to get around without a car.

Washington D.C.Trains, Buses, People: An Opinionated Atlas of U.S. Transit, Island Press

Sure, there are likely bus lines that run farther out beyond the bounds of downtown, but frequency is one of the most important predictors of whether people actually use transit or not. So is distance—you're not going to get many riders if people have to drive to your bus stop—and while some planners consider a quarter-mile to be the ideal maximum distance to be considered "walkable" distance to transit, others, including those running major transit agencies like the Washington D.C. Metro, use a half-mile as the standard. (The book's author, Rice University urban planner Christof Spieler, served on the board of directors for the Houston METRO from 2010 to 2018.)

New York CityTrains, Buses, People: An Opinionated Atlas of U.S. Transit, Island Press

The resulting infographics portray the reality of American transit options. Even in cities we imagine are great for public transportation (New York) there are wide swaths of densely populated geography that are virtually inaccessible. Other cities known for their over-dependency on the car (Los Angeles) actually might have far more transit options than you imagine.

Trains, Buses, People: An Opinionated Atlas of U.S. Transit, Island Press

So what U.S. cities have the overall best transit coverage, according to Spieler? He names these cities as the five best: New York City, Boston, San Francisco, Seattle, and Washington, D.C.

And the most useless? As far as individual rail lines go, Nashville's $41 million Music City Star line carries fewer people than most bus routes. St. Clair County, Illinois, has a MetroLink line running from St. Louis eastward to serve "literal corn fields," Spieler writes. A Cleveland light-rail extension built in the 1990s serves a pathetic 400 people a day. Dallas's system, DART, is the biggest light-rail line in the country, but it "reaches remarkably few places," carrying half as many people per mile as transit in San Diego, Phoenix, or Houston.

In general, recent American transit projects cost taxpayers a ton of money and serve relatively few people—New York, despite having one of the best transit systems in the U.S., has paid $18.9 billion over the last 10 years on a mere three subway stations and one commuter-rail station.

Curious as to how your city measures up? Get the book on Amazon for $36.

[h/t CityLab]