Now, though, Baby Boomers and Millennials are moving back to city centers, eager to get rid of cars and walk to work and to nightlife. In many cities, including Milwaukee and Boston, planners have tried to encourage that walkability by tearing down urban freeways and putting parks and new businesses in their place.

In many other cities, though, including Little Rock, states are doubling down on highways, expanding lanes and building more concrete structures through residential or urban areas. Colorado wants to spend $1.2 billion to widen I-70 in Denver. Louisville is planning to widen I-71 to six lanes, from four. Iowa is widening U.S. 20 to four lanes. And in Birmingham, the state of Alabama wants to widen I-20/59, which passes right through the city center. It’s a testament to Americans’ continuing obsession with cars—citizens have relied on them for decades, and don’t want to think about a life without them. No matter the effects on the city underneath.

“If [the Alabama Department of Transportation] proceeds unabated, they will be reinforcing something that has become a barrier in our community for 50 years, and making sure the barrier stays in place for the next 50,” Darrell O’Quinn, a resident of Birmingham who opposes the widening there, told me.

The expansions are curious especially given the numerous studies that show that widening roads doesn’t reduce traffic. When Texas expanded the Katy Freeway in Houston to 26 lanes to reduce congestion, for example, travel times increased by 30 percent in the morning and 55 percent in the evening.

“Congestion has been looked at pretty carefully [and the conclusion is that] it’s difficult to build your way out,” said Robert Krol, a professor at Cal State Northridge who has studied this issue.

But it can be difficult to dial back highway spending. There’s much more federal money available for highways than for anything else, and that funding is apportioned to states, which can go forward on highway projects without much oversight. Though they could invest in transit or smaller networks of streets, states have prioritized highway construction for more than the past half-century, and it’s easier to keep doing that than to dramatically rework their budgets. And when state transportation departments spend money that comes from outside, they are less likely to feel accountable to local communities than they would be if they were spending local tax dollars.

In Little Rock, the highway I-30 needs to be repaired, the state says, because of heavy traffic on the bridge that brings the highway over the river. The bridge would be unsafe during a seismic event, according to the Arkansas State Highway and Transportation Department, simply called “the Highway Department” by locals. The Highway Department has put forth a plan, 30 Crossing, that would widen both I-30 and I-40. In a 2015 application for a federal TIGER grant, the Highway Department calls it the “largest and most ambitious project ever planned to be undertaken” by the department.