The history of urbanism is the history of technology. City life only exists because technology makes it possible.
Nowadays, though, the word tech conjures up images of mobile apps and Patagonia-vest-wearing dudes1 talking about something called blitz-scaling.2 This is an unfortunately reductive view.3 It’s also one that makes it hard for us to appreciate how important technology is — and always has been — to urban life.
And while technology’s role in enabling urbanism remains obscured, so too do the future possibilities new technologies are about to unlock.
What makes a city great
People trying to Make it Big in the City is what makes The City Big. And the more folks who show up to try their luck, the more luck there is to go around.
Cities, you see, are humanity's great serendipity machines. No one accomplishes anything alone and finding the right economic opportunity, romantic partner, or community of interest is often a numbers game. Cities increase those numbers, thereby increasing everyone’s surface area to luck.
This understanding in hand, we ought to also recognize that what cities provide, they provide more of the bigger they become. In bloodless economic terms, we’d say that the benefits of agglomeration increase with scale. A more accessible description might be to point out that the gulf — economic, cultural, etc — between New York City and a place like…say, Vidor, Texas…is largely a function of size.4
Scale, however, has always had material limitations. Throughout history, that upper bound on urban growth has been defined by technology. And every time we push that boundary out, we've enabled cities to grow.
Scaling economies of scale
Modern cities are an order of magnitude larger than their ancient forerunners.
At the height of its political power in 1 AD, the city of Rome had an estimated population of 1 million people; in the present day, the city hosts a population over four times that amount. More dramatically, Beijing circa 1500 was home to approximately 675,000 people; today, over 22 million people now reside in the capital city.
Modern cities are bigger in every respect (by a lot) and we have technology to thank for making that possible.
For most urbanists, the obvious example of technologically-enabled growth is transportation. Historically, cities have tended to grow out to the distance one can travel in a half hour. As we went from walking, to riding horses, to street cars, to highway-enabled automobiles (and, in some more civilized parts of the world, commuter rail), the distances we were able to travel in that half hour expanded dramatically. The average size of cities grew outward accordingly.
In the same way that technology enabled cities to expand out, it also enabled them to grow up.
Chicago’s Home Insurance Building was arguably the world’s first example of a modern skyscraper. Built in 1884, it made use of a steel frame (instead of load-bearing exterior walls) to reach the then-impressive height of 10 stories.
The Home Insurance Building also employed what I consider the most under appreciated form of urban rapid transit — the elevator.
A fifty-story building without an elevator is really just a six-story building with extra floors. Modern mid-and high-rise construction would be impractical without the elevator, and contemporary cities would be unrecognizable without the denser development that elevators unlocked.
Technology has a long history of unlocking urban growth, but not everything that comes with growth is good. Yet even here, technology has had a role to play in reducing or eliminating the diseconomies of scale that accompany urban growth.
Getting the good without the bad
Living together comes with a lot of upside, but it has its challenges as well. Just as technology has allowed us to unlock more and more of that upside, it’s also been there to mitigate the risks that come hand-in-hand with scale.
For most of human history, sanitation, waste management, and warding off disease has been hard.
Ancient Rome had a system of aqueducts to bring in fresh water. It also had a network of underground tunnels to move waste water back out of the city. Peer cities in ancient China, India, and elsewhere all developed similar systems for bringing in drinking water and removing waste.
These systems, though, often left much to be desired. Most people’s homes weren’t connected to municipal waste disposal systems (i.e. no flushing toilets or running water). Also, what municipal systems did exist in ancient cities was often just whatever river ran through town. There also wasn’t really a concept of waste treatment; the exercise was more about moving in clean water and moving out the waste.
In sum, ancient waste management systems kinda worked. But only kinda. And probably way worse — in terms of convenience and disease prevention — if you were poor.
Fast forward to the 1854 cholera outbreak in London and we start to see the beginnings of modern sanitation technology.
Dr. John Snow5 correctly hypothesized that cholera was being spread through contaminated water; specifically from a public water pump that was drawing water from the Thames downstream of where Londoners were disposing human waste.
He was able to set up a double-blind experiment to prove his hypothesis and help health officials quell the outbreak by preventing access to the contaminated water source.
His work formalized germ theory and set the stage for the modern sanitation systems that collect, remove, and treat the roughly 100 gallons of wastewater we individually produce every day.6
What’s next?
So many things.
On the transportation front, I’m personally most excited for electric vertical takeoff and landing vehicles (EVTOLs). At cruising speeds of up to 200mph and the ability to travel as the crow flies, they could be the next big leap in transportation technology. I still think it’ll take a couple decades for the technology to really take off (pun intended) and a couple more for it to impact the size and shape of cities, but it feels like one of those scale unlocks for urban growth.
In the slightly different context of intercity transit, I’m hopeful that the U.S. is actually about to embrace high-speed rail. Ground has been broken on a Los Angeles-ish to Las Vegas HSR line that should open before the LA Olympics in 2028. And I still have my fingers crossed that the Texas HSR will eventually happen, providing the bones for a future mega-region stitched together by mass transit.
While this isn’t new technology in the global sense, it’s tech that we’ve haven’t deployed in the States. And this gets at when and why we aren’t good at taking advantage of technology, which I think happens for two reasons.
The first is just organizational capacity. California high-speed rail is an easy example to pick on, but the Transit Costs Project has extensively documented how American institutions are uniquely bad at major infrastructure.
The other is the vetocracy we’ve instituted for most land-use decisions in American cities — much of which was set up in response to men like Robert Moses. But as the saying goes, the road to hell is paved with good intentions and the fourth circle of hell now looks like a public meeting filled with the most unrepresentative people you know all hating on duplexes.
We’ll explore both these problems in future posts, but it felt important to acknowledge that while I’m optimistic about the positive impact that technology will continue to make on our cities, that impact doesn’t happen in a vacuum. How quickly the future gets here, how it’s distributed, and the specific shape it takes on is always mediated by our institutions.
Outro
Technology isn’t the only thing that determines the size and shape of a city — but it is the first thing. If we can’t move the atoms around (or safely gather without accidentally inviting the smelliest member of the four horsemen)...the atoms won’t get moved. We have to have the technology to build a fifty-story highrise before we contemplate whether it makes financial sense (or worry about how the local planning commission feels about shadows).
As we consider how cities have changed over time, how they serve us today, and what they could become tomorrow, we need to recognize the role of technology in defining the limits of what’s possible.
And yes, it’s always dudes (science suggests this is chromosomally determined).
Don’t look it up, it’s not that interesting.
Though I’ve never unironically worn a Patagonia vest, I have worked on software products, so I have to take a little of the blame here.
There are some other differences outside of scale, but the less anyone knows about Vidor, the better (aside from knowing that you should never stop there for gas).
This one, in fact, knew a lot.
At least if you live in the U.S.
This is a great writeup, Jeff! Posts like this make me wish that Substack had some kind of "keep forever" button I could use to save this for future reference (stronger than just "like"). Cheers!
This was a great read! I liked how you pulled together examples of technology from throughout history that have made possible more vibrant cities.