Most of the time, the road is far too big, and the rest of the time, it’s far too small

Sunday, November 13th, 2022

Casey Handmer did a bunch of transport economics when he worked at Hyperloop:

Let’s not bury the lede here. As pointed out in The Original Green blog, the entire city of Florence, in Italy, could fit inside one Atlanta freeway interchange. One of the most powerful, culturally important, and largest cities for centuries in Europe with a population exceeding 100,000 people. For readers who have not yet visited this incredible city, one can walk, at a fairly leisurely pace, from one side to the other in 45 minutes.


There are thousands of cities on Earth and not a single one where mass car ownership hasn’t led to soul-destroying traffic congestion.

Cars are both amazing and terrible:

Imagine there existed a way to move people, children, and almost unlimited quantities of cargo point to point, on demand, using an existing public network of graded and paved streets practically anywhere on Earth, in comfort, style, speed, and safety. Practically immune to weather. Operable by nearly any adult with only basic training, regardless of physical (dis)ability. Anyone who has made a habit of camping on backpacking trips knows well the undeniable luxury of sitting down in air-conditioned comfort and watching the scenery go by. At roughly $0.10/passenger mile, cars are also incredibly cheap to operate.


Some American cities have nearly 60% of their surface area devoted to cars, and yet they are the most congested of all. Would carving off another 10% of land, worth trillions in unimproved value alone, solve the problem? No. According to simulations I’ve run professionally, latent demand for surface transport in large cities exceeds supply by a factor of 30. Not 30%. 3000%. That is, Houston could build freeways to every corner of the city 20 layers deep and they would still suffer congestion during peak hours.

Why is that? Roads and freeways are huge, and expensive to build and maintain, but they actually don’t move very many people around. Typically peak capacity is about 1000 vehicles per lane per hour. In most cities, that means 1000 people/lane/hour. This is a laughably small number. All the freeways in LA over the four hour morning peak move perhaps 200,000 people, or ~1% of the overall population of the city. 30x capacity would enable 30% of the population to move around simultaneously.


Spacing between the bicycles, while underway, is a few meters, compared to 100 m for cars with a 3.7 m lane width. Bicycles and pedestrians take up roughly the same amount of space.


Like a lot of public infrastructure, the cost comes down to patterns of utilization. For any given service, avoiding congestion means building enough capacity to meet peak demand. But revenue is a function of average demand, which may be 10x lower than the peak. This problem occurs in practically all areas of life that involve moving or transforming things. Roads. Water. Power. Internet. Docks. Railways. Computing. Organizational structures. Publishing. Tourism. Engineering.

This effect is intuitively obvious for roads. Most of the time, the roads in my sleepy suburb of LA are lifeless expanses of steadily crumbling asphalt baking in the sun. The adjacent houses command property prices as high as $750/sqft, and yet every house has half a basketball court’s worth of nothing just sitting there next to it. Come peak hour, the road is now choked with cars all trying to get home, because even half a basketball court per house isn’t enough to fit all the cars that want to move there at that moment. And of an evening, onstreet parking is typically overwhelmed because now every car, which spends >95% of its life empty and unused, now needs 200 sqft of kerb to hang out. Most of the time, the road is far too big, and the rest of the time, it’s far too small.

People often underestimate the cost of having resources around that they aren’t currently using. And since our culture expects roads and parking to be both limitless, available, and free, we can’t rely on market mechanisms to correctly price and trade the cost. Seattle counted how many parking spaces were in the city and came up with 1.6 million. That’s more than five per household! Obviously most of them are vacant most of the time, just sitting there consuming space, and yet there will never be enough when they are needed!


  1. Bomag says:

    “every house has half a basketball court’s worth of nothing just sitting there next to it”

    I’d say feature, not bug. There is value in space; often pointed out that the wealthy spend greatly for privacy/space. Nice if we can get it naturally. I’m suspicious of economists who preach the gospel of cramming more people into less space.

    I imagine such economists viewing the scene in The Matrix, with the rows and stacks of people pods; they excitedly jumped up and pointed out ways to fit the pods even closer together.

  2. Michael van der Riet says:

    Despite the huge monetary cost compared to using public transport, people prefer cars. That’s how much the benefits are worth to us. There’s a huge time cost as well, and the huge unpleasantness of sitting in congested traffic surrounded by aggressive shall we call them jerks. Yet people prefer cars. Public transport has to suck very deeply. Bicycles come off very much worse in a confrontation with a car or truck, there’s inclement weather, and you get to work smelling of sweat. Everyone knows this, but nobody wants to confront it. There are few incentives to move people away from cars.

    Autonomous cars would solve most of the problems, but all human drivers would have to be removed from the road first. I could easily see myself summoning my individual vehicle and being taxied to and fro while occupying my time with work or leisure. My NetLogo model says that autonomous vehicles would move far more smoothly because they can follow without spacing between cars and when the car ten cars ahead has to brake, all the cars behind it brake automatically with zero reaction time.

    It’s everyone’s experience that during school vacations the traffic volume only has to drop by a fifth or less and the daily commute is plain sailing. Where that genius came up with a number like 3000 per cent might have been Planet Zog or the Magical Mushroom Experience. But then that’s the hyperbolic way they’re taught at Alarmist College.

  3. Douglas says:

    “According to simulations I’ve run professionally, latent demand for surface transport in large cities exceeds supply by a factor of 30. Not 30%. 3000%.”

    Maybe I’ve been reading about congestion on the ‘antiplanner’ blog for too long, but I really suspect that simulation is wrong.

  4. Jim says:

    Michael van der Riet: “Public transport has to suck very deeply.”

    It doesn’t suck in countries without DIE (Diversity, Inclusion, and Equity).

    Weird, huh. It’s almost like…

  5. Jim says:

    Look, no one wants to say it, but the reason that American cities are inhospitable asphalt hellholes with no public spaces and nowhere to go that isn’t ruthlessly surveilled beyond the wildest dreams of the U.S.S.R. is because the ADL, the SPLC, and other Jewish lawfare attack groups will bankrupt you with legal process of a secret and quasi-criminal nature if you dare to suggest that People Who Mug belong to one of two or three very distinctive groups and that there are very simple and easy ways for state and municipal governments to guarantee a reasonable quality of life to their constituents, such as by erecting borders to control ingress.

    To the Supreme Court I very respectfully say only that the mere traversal of state and municipal borders does not rightly fall within the purview of interstate commerce, and fuck you.

  6. Jim says:

    “People Who Mug”

    POC (People Of Crime)

  7. Siegfried says:

    Public Transportation rhymes with Pubic Lice. What works well in Moscow, or the pre-Civil Rights era US has morphed into an expensive and dangerous mix of bugmen and homeless scum. Public Trans is a prime example of the designed chaos of the US Elites and their tribes. With the Homeless Industrial Complex being used as a weapon against the working classes it is hard to imagine the US economic system doing anything but devolving into chaos and eventual Balkanization. Until I can legally defend myself on an urban bus line or fixed line train, a POV will have to suffice.

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