How the Korean capital, Seoul, knocked down a highway, attracted less traffic, and upped its quality of life. An homage to celebrate the 10th anniversary.

All gone. Simply gone. Just a few gray concrete beams remain, jutting out from the verdant embankment, to remind us of the former urban freeway that used to tower over the area.

And now: laughing kids, lovers, and families on their way to a picnic. Almost exactly a decade ago, Seoul, South Korea’s 22-million metropolis, claimed back what a previous generation had covered in concrete: a slice of nature or, to be more precise, the Cheonggyecheon River, buried under tarmac and cement in 1961.

The effect of the restoration is tangible. Noise and particulate matter levels have declined dramatically – and even the average temperature along the Cheonggyecheon has fallen well below (by 5-6 degrees Fahrenheit) that of neighboring residential areas. During summer, the river serves as a natural cooling body within a heated city that houses almost half of South Korea’s population.

Planners removed approximately 4 miles of freeway and restored 2.5 miles of riverscape for the local residents to enjoy – at a cost of €300 million. Even insects and fish have returned to the Cheonggyecheon River, turning it into a teeming ecosystem.

Fewer streets – better traffic flow?

So, what happened to all the cars? The restored river didn’t just flush them out to sea. Seoul has an estimated 2.5 million passenger cars – plus a host of taxis, buses, trucks, motorbikes, and mopeds.

Common sense would suggest that this sheet metal avalanche only moved a few streets, clogging traffic arteries down the road. Yet none of this happened.

While the cars didn’t simply go up in smoke, something similar did occur. In 2006, John Vidal reported on a small miracle in the British Guardian, commonly known to traffic planners as the Braess paradox. Its non-scientific explanation: If every driver seeks to travel by the quickest route, adding more streets doesn’t necessarily equal improved traffic flow.

Even the opposite can be true: All of a sudden, less (streets) can mean more (speed for everyone).

Cheonggyecheon river selfie tourism
Photo: smart magazine
Cheonggyecheon river rest under bridge
Photo: smart magazine
Cheonggyecheon river pedestrians
Photo: smart magazine
Cheonggyecheon river street art
Photo: smart magazine
Cheonggyecheon river plant
Photo: smart magazine
Cheonggyecheon river lantern festival
Photo: travel oriented , CC BY SA-2.0 via Flickr
Cheonggyecheon river walk by the canal
Photo: smart magazine
Cheonggyecheon river couple waterfall
Photo: Carlos Felipe Pardo, CC BY 2.0 via Flickr

Less is indeed more

This is exactly what happened in Seoul, according to Professor Kee Yeon Hwang of the Department of Urban Planning. While some drivers simply changed their route, others switched transport or even gave up driving altogether.

In the overall traffic mix, the loss of the multi-lane freeway didn’t make a dent and traffic continued to flow – even better. This ostensible dichotomy is explained by a theory devised by German mathematician Dieter Braess who, in 1968, described the effect as follows:

“The best possible route not only depends on street conditions, but also on traffic density. If every driver picks a route that is perfect for them, this doesn’t necessarily lead to optimum travel times. In some cases, an expansion of the network can even reroute traffic flow in such a way that travel times are extended.”

So, should we take from this that less selfishness serves the community? The phenomenon is not restricted to traffic, but applies to any system where many individuals with limited knowledge try to reach the best solution for themselves – which doesn’t always lead to the best possible overall outcome.

The Cheonggyecheon breathes life and greenery into the heart of Seoul.
Photo: Brian Kusler, CC BY 2.0 via Flickr

City planners make good on a promise

But let’s return to South Korea, which heralds a general rethink. City planners are making good on their promise of more space and greenery, finally treating the metropolis and its residents to the elusive tenets of modernity (faster, further, larger).

And this is a good fit and premise in an era of re-imagined globalism. Cities are not only becoming humanity’s most natural habitat (after all, very few of us have encountered real wilderness), but they also compete for the best hearts and minds.

This, in turn, attracts investment to places that promise a good quality of life. By now, the seemingly dry metropolis rankings have taken on a life of their own, evolving from mere tables of figures into tangible measures of economic success.

All of a sudden, nearby nature, recreation, and quality of life have become major factors. And that might be the only real paradox in a world geared towards efficiency and integration.

Cheonggyecheon river at night
City planners are making good on their promise of more space and nature.
Photo: d’n’c, CC BY SA-2.0 via Flickr

Header image: travel oriented , CC BY SA-2.0 via Flickr