The highway has been doubly destructive on the American city

http://www.theatlantic.com/business/archive/2016/03/role-of-highways-in-american-poverty/474282/
The Atlantic - The Role Of Highways in American Poverty

This article is a brief and selected history from the 1940s until very recently relating to the use of highways and their construction in cities. Semuels asks us to imagine that city planners in the 40s-60s used a kind-of planning heuristic of the human body to analogize the American city. The rapid growth in automobile ownership (from 60 to 80% of the public from 1940 to 1960) and growth in developing cheap land in the suburbs lead to traffic (congestion) that needed to be alleviated by making "arteries" for transport of blood (labor) into the cities. Where did the money to build these expensive highways come from? The Federal government would cost share with the states, starting at 50% in 1944 and reaching 90% cost coverage by 1956. The first trouble was that it was predominately white people who moved to the suburbs, due to restrictive covenants, redlining, and other racist practices.
People of color remained in the cities, living in dirtier and more crowded conditions. These neighborhoods were then considered unhealthy-- slums-- by city planners. The trouble was that while there was money available for urban renewal, renewal was expensive and planners instead found it easier to simply destroy the old neighborhoods by putting new highways into them. The highway, then, was considered the low-cost solution not just for white flight but also for displacing people of color. And yet displacing black neighborhoods led to more white flight. The example of Syracuse, NY is offered as a prototypical case.
It isn't surprising that people born into poor neighborhoods have a very difficult time getting out of them, even as redlining and other overtly racist practices are now illegal. Greater integration is better for combating poverty, and the highway has been not just the literal but also symbolic divide between better and worse economic conditions. This trend is starting to reverse, as outlined by some more progressive thinking in some cities over the last decade or so.