Earlier today I tweeted this:

What Other Cities Learned: These five tore down highways and reaped the rewards. http://t.co/aR8STHTX9o #urbanism pic.twitter.com/I07iwRF8EP

— Brandon G. Donnelly (@donnelly_b)

December 17, 2014

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It’s a link to an article talking about 5 cities – New York, Milwaukee, Seoul, Portland, and San Francisco – who all demolished an elevated highway that used to run through their downtowns.

To be completely fair, some of these cities didn’t really have a choice. San Francisco’s Central Freeway was so badly damaged in an earthquake that it had to be closed. But it doesn’t make the lessons any less relevant.

In all of these cases, the elevated highways were taken down and never replaced with another highway. Some were turned into large boulevards. Others were turned into parks. But in none of the cases was a new road of similar capacity built.

Intuitively it might seem like this would cause utter chaos. I mean, where were all of these cars going to go? 

But that didn’t happen. Instead, demand redistributed itself. Car volumes dropped dramatically. More people took transit. Some people took other routes. And some people traveled at different times. Oh, and nearby property values all went up.

And the reason this happened is because of something that economists call induced demand (I’ve written about it before, here). What it means is that as you increase the supply of some valuable good (such as free highways), more of that good becomes demanded.

In other words: more free highways = more cars on the road.

So if you’re a city – like Toronto – with an elevated highway running through your downtown, you should give this some serious thought. The outcomes aren’t as bad as you might think. In fact, they’re quite good.

Image: Seoul via D Magazine