11 Comments
Oct 10, 2023Liked by Ben Southwood

Agree with the overall points, but I think many who use the term induced demand actually just mean suppressed demand. You are right that suppressed demand is a more accurate way of phrasing it.

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Oct 20, 2023Liked by Ben Southwood

Hot stuff here, very nice. Admittedly, I am less motivated to comment just to say "I agree" vs when I think there's an "umm,, akshually" point to be made, and I think there are maybe a few

- The Lubbock 15 min city, even if facetious, kinda misses one of the understated appeals of a "15 minute city" in that people should not *need* a car (with surprisingly large ongoing costs) to be able to get around normally and live a middle class existence

-- and, at least where I'm at, much of suburbia does have a "viable" density for transit eg every 15 min, 10 min (heck, even after the "streetcar suburb" era), and it is more authorities not budgeting or servicing it. Ie trying to think of it as meeting demand, like seeing if a bridge should be built by counting the number of people coming across (rather than considering suppressed demand)

- The "Atlanta is a Garden City" is a spicy take that feels kinda wrong, but I can't fault except for "the vibe" I guess all I can think of is the "forest" that Atlanta appears to be nestled in is really just suburbs. But, eh, a bunch of leafy suburbs is close enough? to a forest?

- And about the size comparison of Atlanta to Chicago - was Chicago in 1915 really confined to Cook County? I wonder if there were suburbs outside the county boundary that are still functionally suburbs of Chicago (like today, where suburbanisation? urbanisation extends over to Wisconsin and Indiana bythe looks of it)

Insightful to me

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author

Thank you for these. In turn:

1) Yes that’s a fair point. Of course, it’s easier for me to say this in England because nearly every town and city in the country has neighbourhoods where you can live far free easily if you wish. I would find Lubbock alienating personally. But many love it! And I think the core thing about a 15 min city is the amenities within reach - after all many extend it to 15 mins by bike.

2) I think more investigation necessary here. I gather there are railway suburbs with American (10-20du/ha) densities around the NY metro - and there certainly are around the SE of England. But I suspect most of these services are heavily subsidised in the USA. But you may be right on density. In which case I would suggest that crime/anti social behaviour is the issue and if we could get that down, these Americans would ride transit.

3) It looks basically like a forest from ground level and from space. They are incredibly leafy suburbs. Every single person a patch of garden. Oh I’m sure Ebenezer himself would find a reason to quibble but I think he’d be shifting the goal posts.

4) Unsure on this, but the London in 1870 one is accurate as are the medieval ones. I stole from Thomas Pueyo. This map (of 1900 development suggests yes it was that compact) https://i.pinimg.com/originals/58/1a/c4/581ac42eb1ceb836a3ad70db4cffb0dd.jpg

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I blame the evil tyrant named Kevin Leonpacher for Atlanta's car dependence.

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I think the final figure is very misleading. Sure, the total area accessible by care may be large in many US cities, but at the same time these cities are sprawling so one has to go very far to find the same range of places/services. One could probably find as many shops and restaurants within 1 mile in Paris than within 10 miles in LA, so the emissions are way greater in the car-centered places for what advantage?

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+1

You may be able to access more km^2 if you have good roads but the sprawling design with lots of parking means that there is fewer amenities per km^2.

More interesting metrics to me is jobs or amenities accesible in 30 minutes not parking lots and weed filled medians.

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Your first point is garbage and I see no way to salvage anything from it.

By your logic all current forms of traffic are poor substitutes for zero-cost teleportation, which is latently in massive demand. I think this idea is actually possibly defensible in some arcane pure-logic sense (if there was zero-cost teleportation available to me, I would certainly use it over highways or trains) but it is orders of magnitude less useful than the idea of induced demand, which you rail against as "false".

You presuppose that the "latent" demand is specifically for roads, when in reality the demand is for whatever mode gets the traveler from origin to destination in the way that meets their cost/comfort/speed requirements best. The demand is not latent; it is being met by something other than roads. If there is not enough throughput along the busiest corridors, we have the choice to expand access to any one of the currently available modes, which will improve that mode's comfort, cost, and/or speed. This will (say it with me) induce more demand for that mode, and we can (if we want to) choose where we want to induce that demand based on what will be most sustainable long-term.

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While induced demand, as typically explained by urbanist, is really just latent demand, I do think induced demand actually exists.

If you build a new freeway though a city, you are are not just providing a road to travel on, you are also creating a roadblock. A person who might be one mile from a store, now has to take a detour to get to the store and might have to travel five miles. That is not only longer travel (induced demand), it might also move the person from walking or cycling into a car (again, induced demand).

The above mentioned freeway will also create more noise, so people moves farther away inducing even more demand.

A new or expanded freeway will not just create more cars on the freeway, but also on side roads. Those roads may become dangerous or unpleasant from increased traffic, again inducing more people to not walk or bike, but go by their own car. Again, induced demand.

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This is a good insightful assessment. It is certainly not a foregone conclusion that road travel speeds at any time period are doomed to stay down at some inefficiently low level. Now we have GPS-based travel data such as TomTom, we can see there is a wide range of travel speeds across the data for cities. There doesn't seem to be much analytical effort being expended on working out the reasons why. There seems to be a prevailing ideological barrier to identifying and maximizing the gains from automobility itself, instead it is assumed that "making people drive less" is the objective.

Buried in all the confusion, is the factor of "co-location" which is surely the one that will make the most difference. The way that central planners think they can get us there, is by rationing the overall land supply and upzoning and building high density. But there is no data that shows any success via such approach. Hong Kong has extraordinary density but "co location efficiency" is elusive; monster commutes are the norm.

Contrary to planners assumptions, forcing density by rationing land supply pushes up the urban "land rent" curve and this results in the "pricing out" of the most possible people. Housing is demonstrably NOT more affordable even as the size of homes shrinks and they become more stacked and packed. The price of land embodied in their cost is higher, not lower, in spite of the very much smaller footprint per unit. The price of land varies by a factor of tens, or hundreds or even thousands. The lowest land prices are found in the free-sprawling cities and this price is so low that the size of lots cannot push the price of housing up anywhere near the high-land-price cities.

The basic economics underlying this, is that prices can be derived "differentially" or "extractively". The latter involves consumers paying the very maximum they can stand, for a necessity. This applied to almost everything, including food and housing, back in Victorian times. Food and almost all consumer goods came to be priced "differentially" when transport, refrigeration and free trade rendered the supply effectively superabundant, so no owners of resources could charge "extractive" prices for the product of their resources.

Housing came to be also priced "differentially" when automobility rendered the supply of land on which "urban" populations can live, superabundant. The change from Victorian era housing markets, to that of the mid 20th century, is so blindingly obvious that it is extraordinary that there is so much hate for the process that enabled it. What we do by curtailing that supply of land in very low value uses - farmland is $10,000 per acre almost everywhere - is flip urban land markets back to "extractive" condition. The price of sites is worked out backwards - even developers can candidly tell you this - from what the end consumers of housing can be gouged to pay for it. The greater the allowed density, the higher the site value, and this elasticity is exponential. The price of land can be tens, hundreds, or even thousands of times higher, as you cram more people in. The result is not only housing cost stresses, but "pricing out" effects delivering the opposite of the intended co-location efficiencies.

If we simply allowed sprawl and low land prices but provided other incentives for people to reduce their travel distances by co-locating more efficiently, we would actually achieve the best of both worlds, rather than doing nothing but harm.

In all the factors that create "demand for travel", the big one that the official experts do not notice is "escape from land rent gouge". In the third world, as people get motor scooters, their slums spread out and become more spacious. No "highway subsidies" are necessary to drive this process. Even Frank Lloyd Wright, not an economist, saw that it was simple escape from rent gouges in old legacy city centres, that drove "sprawl" in his time, and he applauded it. The Leavitt Brothers were students of his.

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Apr 21·edited Apr 21

Ben, are you any of the following?:

1. a NIMBY

2. a fossil fuel industry shill

3. an auto industry lobbyist

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author

Insofar as I am known for anything, it is for being a YIMBY who loves walkable neighbourhoods!

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