It may sound obvious, but it's a big problem in cities across the country.
In every urban demographic group in our State of City poll, the majority commuted by car.
Scientists working in smoggy Houston say planting a 1.5-square-mile forest would make the air more breathable.
Texas Central Railway intends to build a Houston-Dallas line with private money.
By eliminating route redundancies and emphasizing ridership, the city thinks it can get a better trip at the same price.
But they're not alone: roughly half the nation lives with unhealthy concentrations of ozone or particulate pollution.
New York and L.A. are losing more Americans than they're gaining, but the flood of immigrants more than makes up for it.
In a city where nine in ten drive to work, the answer could reshape the future.
The population of cities with more than a million people jumped 3.2 percent, much better than the 2.4 percent for the U.S. overall.
Questioning the numbers behind the new ridership "record."
How U.S. cities stack up economically worldwide.
A complicated geography of churches, produce, and beer.
Car culture may not be making us sick. Cities aren't necessarily healthier than suburbs.
Kyle Naegeli of Texas says he's hauling in nice-sized catfish and bluegills from his suburban storm drain.
And other eye-popping comparisons.
Our series drew impassioned responses from city boosters and haters alike.
Young professionals see the Texas boom town as a bastion of the traditional American Dream.
Major urban areas are magnets for the uninsured, and the state politicians who turned down the Medicaid expansion are not the ones who will pay to treat them.
Though now likely doomed for demolition, when the Astrodome first opened in 1965, it was a profoundly American invention.