Edge cities: skylines built at a highway exit

Picture a country crossroads surrounded by cow pastures. Just a few decades ago, there was almost nothing there. Today, at that same spot, a skyline rises. Office towers, shopping malls and miles of parking. More people work there than actually live there. Its offices hold as many workers as a whole downtown. And yet, it has no old quarter. No main square, no cathedral, no clear mayor. A place like this really exists, near Washington. It is called Tysons Corner, and it seems sprung from nowhere. It looks like a city. It works like a city. But nobody built it as a city. How does a whole city appear at a highway junction?

This kind of place has a name. The journalist Joel Garreau studied it closely. He named them edge cities. They are dense concentrations of offices, retail and jobs. But they rise on the edge of the metropolis, far from the old center. They are not a simple residential suburb. A residential suburb is, above all, beds for sleeping. Nor are they the old downtown, with centuries of history on top. They are something else, new and in between. Garreau saw this form repeat all across the country. A city that grows on the periphery, not in the heart. And one almost nobody had managed to name until then.

Garreau's rules

How do you recognize one of these cities? Garreau proposed some very concrete rules. First, millions of square meters of office space. Second, retail the size of a large shopping mall. Third, and this is key, more jobs than bedrooms. People travel toward it, not only away from it. Fourth, the population sees it as one place with a name. And fifth, the most astonishing rule of all. Thirty years ago, there were only fields or scattered houses. In other words, it is a working city in full swing. But younger than many of its own office workers. A city that appeared within a single generation. Almost nobody planned it; it simply grew.

It is worth seeing what made that leap possible, because it was not the motorway alone. Three more things were needed, all invisible in the landscape. First, air conditioning, which allowed deep sealed buildings where every office had once needed a window. Second, the telephone and later the network, which released offices from the downtown where their bosses met. And third, cheap farmland nobody was protecting. Put those three together with a motorway exit and you have an instant city. No public decision summoned it. It was the result of there suddenly being no reason to be downtown.

Car, highway and cheap land

And why did these cities appear? The answer is the car, the highway and cheap land. After the war, the automobile freed offices from the center. You no longer had to sit beside the train station. At highway junctions, land was plentiful and cheap. Zoning rules kept houses, shops and work apart. And companies fled an expensive, congested downtown. Each company that moved drew in the next one. The edge city is what the car builds when land is abundant. It grows at the highway ramp, with no overall plan. Just as old cities were born by a harbor or a river. Only its river is a high-speed road.

And that comparison with the harbour breaks down at one important point. A harbour creates a frontage, a place where the city looks at itself. A motorway exit creates nothing of the sort. The buildings turn their backs on it: they show the car park to the road and hide the entrance behind. Nobody walks from one tower to the next even when they stand two hundred metres apart. There is no pavement joining them, and crossing means four lanes of traffic. The result is an archipelago of private islands separated by asphalt. Each works well inside. Between them there is no city, only motorised distance.

Scholars saw here a completely new urban form. And they rushed to name it, each in their own way. The historian Robert Fishman spoke of the technoburb. A territory with no clear center, no edges and no borders. A place where you cannot tell home from office or shop. The geographer Edward Soja called it the exopolis. The city turned inside out, with life spilling outward. The action moved from the heart to the outer ring. The edge city breaks our old mental map. That map which separated the center from the outskirts. Now the center is everywhere and nowhere. And that unsettles us, because we no longer know where the city is.

Many jobs, few homes

There is an underlying imbalance that explains many of its problems. These cities have far more jobs than homes, and on purpose. An office pays taxes and barely uses municipal services. A home pays less and fills schools, parks and libraries. So it suits every town to attract offices and hold back houses. Since they all do the same, nobody builds where it is needed. The people who work there end up living far away and driving every day. The traffic jam is not a failure of foresight. It is the accounting consequence of a calculation each council got right on its own and wrong together.

Here we reach the most uncomfortable point. Nobody voted for these cities. They were not born of a public plan or a debate. They were assembled parcel by parcel, by private developers. Many have no mayor and no clear limits. Nor do they have a real public square. Only roads, parking lots and private property. Their meeting place is a mall, which has an owner. They are built for the car, so without one you are trapped. And they concentrate jobs far from where poorer people live. Whoever cannot afford a car is left out of the deal. The rules are written by the market, not the citizens. The accidental city is also an unaccountable city. It grows without anyone deciding its shape.

We should, however, listen to the other side. The edge city also brought good things. It brought work closer to millions in the outskirts. It offered cheap offices and a very dynamic economy. The old center was also expensive, congested and exclusive. And there is a nuance that complicates the picture further. The researcher Robert Lang studied offices on the periphery. He found that many do not even form recognizable cities. They scatter into isolated buildings, with no name or center. He called them edgeless cities. If the edge city already had no center, this one has nothing. The trend did not stop. It dissolved even further.

Bring the train, densify around it

And some of these cities are trying to correct themselves, with mixed results. The recipe repeats: bring the train there and densify around the stations. Replace surface parking with blocks that have real streets. Tysons Corner has spent years on that attempt, with a new metro and a plan measured in decades. The obstacle is neither technical nor financial. It is that the land is split among hundreds of owners, each with their plot and their car park. Rebuilding an urban fabric demands agreements nobody has the power to impose. It is far easier to build an accidental city than to turn it into a city afterwards.

So let us return to the opening question. How does a city spring from nowhere on a highway? Because we changed what a city needs to grow. No longer a harbor, a square or a cathedral. A highway ramp and cheap land next to it are enough. The edge city is not an accident of nature. It is the predictable child of the car and the property business. The real question is not how they appeared. It is what we lost by letting them grow with no plan. We lost the square, the shared center, the city as a public thing. We gained offices, but we lost the agora. The cow pasture became a skyline nobody chose. And there is a question these cities leave open that concerns all of us. What happens when one of them grows old? A historic centre has buildings that can be converted: a factory becomes housing, a warehouse becomes a market. An office tower from the eighties, with its deep floors and sealed windows, becomes almost nothing. And when work moves elsewhere again, what remains is a building expensive to maintain and hard to reuse. There are already empty malls nobody knows what to do with. The accidental city grew fast because nothing tied it down. And that same thing leaves it rootless when the flow moves on.

And that story weighs more than the towers themselves.