Dwight D. Eisenhower’s grand scheme to connect US cities to one another with interstates was a great idea. It enhanced trade, economic development, and mobility.

By contrast, jamming interstates and freeways through cities — something Eisenhower never envisioned — was a terrible idea. The power of cities is in the connections that form among people and institutions in close proximity. Intra-urban freeways destroy that connectivity. They chop cities into pieces, creating disconnected zones, isolating people from business districts and often from urban waterfronts. They occupy enormous swaths of valuable land but produce no tax revenue; they only absorb revenue in maintenance costs.

What’s more, the impact of urban freeways is not evenly distributed. It is most often poor communities and communities of color that are displaced to build freeways, and it is most often those communities that get herded into low-value zones adjacent to freeways.

Earlier this year, the US Department of Transportation launched a new initiative meant to undo some of the inequities wrought by such projects over the years. At this point, the ill effects of urban freeways are pretty widely accepted.

The difficult question of what to do with existing urban freeways

A few cities (see: Vancouver) were wise enough to avoid urban interstates in the first place. But many, many others (see: my home, Seattle) were not so wise. So what do you do when there are already interstates and big highways cutting your city into chunks?

Some cities have made the bold choice to remove freeways altogether. The evidence from those experiments is overwhelmingly positive — see this post, or this one, for some examples (and great before-and-after pics); see here for a more formal list of case studies. I am not aware of a single example of a city that removed an urban freeway and later decided that doing so was a mistake.

However, the notion that you can rip out a freeway, traffic will simple disperse, and the reclaimed land will produce more value than what it replaced is highly counterintuitive to most people, including most city officials. Despite copious empirical evidence to the contrary, they simply cannot shake the notion that traffic is a static quantity that will flood onto urban surface streets if freeways are gone.

This Chris Jagers post points to my favorite news story on the subject, from the San Francisco Chronicle, in the wake of the closure of the city’s Central Freeway in 1996.

Traffic experts appear to have produced a minor urban miracle: the closure of much of San Francisco's Central Freeway without major traffic problems. But they have no idea how they did it.

Unpredictable magic! That keeps happening again and again, in Seoul, Portland, Milwaukee, Madrid, Toronto.

We know why freeway closures don’t cause traffic problems, at least at a general level: Commuting drivers choose other regional routes, local drivers choose other forms of transport, and thanks to the new land uses and connections freed up by freeway removal, fewer people need to travel long distances. At this point, we probably shouldn’t be surprised anymore.

Nonetheless, people still don’t believe it, so many cities, stuck with urban interstates and freeways, see no choice but to double down, chasing the “sunk costs” of all that asphalt with more spending and more building.

Which brings us to Louisville.

Oh, Louisville

Louisville, Kentucky, is crisscrossed by interstates 64, 65, 264, 265, and 71. It is an unfortunate situation. Particularly egregious is the stretch of 64 that neatly cuts the city off from its waterfront

Nowhere are the city’s freeway-choked troubles more visible than at the Kennedy Interchange, aka, “Spaghetti Junction,” where 64 and 65 meet just north of downtown Louisville. Here’s an aerial shot from 2006:

Spaghetti Junction was long unsafe — several points required headlong switching of lanes to catch exits and many of the overpasses no longer met federal safety standards — and, like many urban freeways, parts were reaching the end of their lifespan. City leaders faced the question of what to do about it.

In the late-2000s, a group of activists and businesses pitched “8664,” a campaign to rebuild the East End Bridge (completing the 265 ring road and diverting a ton of traffic) and rip out I-64 along the waterfront, replacing it with a surface boulevard.

The idea had been floating around since at least 1999. Here’s a video about it:

Sadly, it never went anywhere. As usual, removing a freeway was characterized as pie-in-the-sky hippie idealism, while dumping billions more into huge freeway expansions was cast as the sensible choice.

Originally the project was going to be gargantuan, with a six-lane freeway through the East End, at a cost of $4.1 billion. In 2011, Indiana and Kentucky agreed to scale back to $2.6 billion. Some of the widening and expansion of freeways was ditched. But the project still included an expansion of Spaghetti Junction. Construction began in 2014.

Read this New York Times story for a capsule history of the divisive project, and urbanist Aaron Renn’s blog (start here) for why it has been, like most giant freeway projects, a huge boondoggle that will cost more and carry fewer drivers than projected.

Here’s what the construction company, Ohio River Bridges, planned (this is a rendering):

Here’s the envisioned “stack,” which will straighten out some routes, improve merging, and otherwise make life safer for drivers.

Anyway, now the expansion is finally done.

The new Spaghetti Junction in downtown Louisville is finally complete. Check out our aerial photos of the crossing https://t.co/rwhQVfY0CS pic.twitter.com/vlofp77N9c — Courier-Journal.com (@courierjournal) December 27, 2016

For scale, note the baseball stadium in the lower left:

At least they’re going to plant some trees around it.

Speaking of which, the expansion ate 33 acres of urban forest. Louisville has the highest “heat island” effect of any city in the country, and the skimpiest tree canopy.

Oh, and it also ate 30 storefronts, most in minority areas of town.

Yikes! Louisville's "Spaghetti Junction" and free expansion projects destroyed 30 storefronts, but downtown's drive-thru McDonald's remains https://t.co/X83I8m02fd — CNU NextGen (@cnunextgen) December 30, 2016

Louisville will remain separated from its waterfront by a giant elevated interstate, but it is now easier and safer for drivers to get past Louisville.

Cities are places to live

Cities need to start thinking about themselves as places to be, to live and work and play and socialize and collaborate, not as infrastructure designed to facilitate automobile travel. It’s not a huge imposition to ask regional travelers to go around cities rather than through them.

And ripping out freeways has only helped the cities that have tried it. The “fundamental rule” of road congestion says that more road capacity leads to more traffic. It’s called “induced demand.” But the inverse also seems to hold true, at least for urban freeways: reduced road capacity leads to reduced traffic. If you stop inducing demand, demand falls.

Local drivers have consistently proven more flexible than traffic engineers predict. When freeways disappear, they do not simply drive their cars onto surface streets. They shift or cancel trips, or switch to different modes of transport.

The even-more-fundamental rule of road congestion might be this: as long as roads are free to use, traffic scales to fit (or rather, to congest) available roadways.

Traffic congestion can never be “solved” unless a city shrinks. What growing cities can do is ensure that their residents have a range of pleasant, reliable transport choices, walkable communities that minimize the need for auto travel, and a range of public and private spaces devoted to human-scale, human-speed activities — for collaboration and innovation and all that, yes, but also just for the casual, spontaneous social contact from which communities are built.

Other cities have choices — see the Congress on New Urbanism’s list of Freeways Without Futures for some good targets. Whether we cap, bury, or remove freeways entirely (listen up, Dallas), they should be no part of life in a city. Cities are for people, not cars.