Hacker News Reader

Comment by jjoonathan | Hacker News Reader

The dreadfulness of the city comes from economic conditions, but if you are a citizen, economic conditions come from:

* How hard you can make business compete for your business (∝ range^2 * density)

* How hard you can make real estate compete for your business (∝ range^2 * density)

* How hard you can make business compete for your labor (∝ range^2 * density)

Having options is good, density gives you options, but range gives you options squared. The absence of cars improves density, but it also decreases range by 10x and range^2 by 100x. It is far from obvious to me that density improvements outweigh this on balance.

Density has undeniable efficiency benefits, but if they accrue to capital (primarily, entirely, or more-than-entirely) and you are a laborer in Magnasanti, the outcome is not good for you.

View on HN

I think it's a little unfair to pretend the quadratic range term dominates the "linear" density term. If you think about it for a moment, the density describes area, so already has a ^-2 (to the -2 power) incorporated into it.

If we lived in a 3D world, there would be a negative third power incorporated into it (although you'd also have a range^3 term)

In reality both terms contribute equally.

Considering the range of densities and ranges available in the USA, density currently makes more of an impact. Speeds range from 10mph at the minimum (a typical net average speed if you're biking or taking subways and walking connections through Manhattan) to 60mph at the most (a typical speed limit on a rural highway) That's about one decimal order of magnitude.

Density on the other hand varies much, much more. There are rural areas with a handful of people in a square mile, and places with 50,000 or more people in a square mile. That's more like 4 orders of magnitude.

This matches up with the anecdotal observation that in terms of "How many employers/restaurants/people/etc can I get to within a 15 minute trip" is far larger in denser bigger cities, despite travel times being slower. Faster travel times just cannot keep up with the low density needed to allow cars to reach those speeds.

At even moderate traffic levels car speeds fall dramatically and often below speeds offered by trains. Trains have much higher capacities and so don’t fall victim to congestion as easily. And even commuter trains have higher speeds than cars.

> Trains have much higher capacities and so don’t fall victim to congestion as easily.

All it takes is one stopped train to cause a big mess on most commuter rail lines.

Commuter rail does better than cars on-peak, usually, especially with limited stop service. But off-peak, cars with no stops and point to point routing and no wait for the next take much less time.

You could say the same thing about car accidents, which are much more frequent, so I don’t know that it’s a disadvantage.

It's usually easier to route around an accident in a car than than in a train. A blocked lane can be passed on the shoulder, but trains have a hard time doing that.

At extremely low capacity and low speeds in any sort of meaningful traffic numbers, due to the reduced number of lanes and all the rubbernecking. And plenty of accidents close highways in one direction.

You have to walk to the train station, wait to get on the train (plus buffer for unreliable/full trains), wait at every stop in between, and walk to your final destination. You're right about congestion, though, and rush hour probably does dominate the equation for commuters.

Still, in the city you pay a lot more for real estate and get a lot less. It is very important for models to include that aspect: do the benefits of density accrue to you, or to your landlord?

Finding parking alone in a major downtown like Manhattan is time-consuming.

Metro-North from Connecticut to NYC has a speed of 80MPH, and combined with pretty good acceleration from electric propulsion, is often traveling faster than cars.

---

You get a lot less real estate but you do get a lot more in terms of amenity.

* a lot of amenities found in major cities are there because the major city provides critical mass for niches. (If you don't have enough gay people you won't have gay bars, if you don't have enough Chinese people you are not going to have grocers with Chinese produce, you need a big enough population awake late nights to support diverse late-night food options, you need enough arts patrons to support a museum, etc.)

* switching jobs is easier in big cities, particularly for people with specialist jobs. Remote work is more of a thing post-COVID, but realistically speaking a lot of companies will limit that to areas where they are already set up (since even in the US tax, employment benefit, health insurance etc. regulation varies significantly by state), and major cities are better covered in terms of companies already being tax compliant.

Big cities aren't for everyone, but also suburbs are not for everyone, and small towns are not for everyone, and we are seeing that there is more demand for big city than is currently being satisfied.

Square laws are applicable in situations where a traveler can travel from any arbitrary point to any other arbitrary point. Bandwidth isn't considered, but it's definitely the greatest limiting factor for routine human travel today.

Example: crowd crushes are bandwidth spikes

I don't know where you're from but I view this sort of argument as basically american parochialism. The numbers don't mean anything, noticing square laws exist doesn't really have any affect on this domain. The dozens or hundreds of practical accommodations due to climate, culture, history, funding, aesthetics etc etc add up to much greater than "range ^ 2" or whatever.

Other configurations do work, in different ways and to varying degrees, all over the world. The people there aren't meaningfully less free because of the transit structure around them, and in fact the cars-only model is the absolute most restricting one you can have, given the obvious fact that not everyone can drive at all stages of their lives.

American society is structured around the idea that all gains outside the most private spheres rightfully belong to the corporate entities that can control them. But that isn't a given either; many places don't work that like and it's not necessary that we do.

> The people there aren't meaningfully less free

They pay twice my mortgage to rent a tiny, cramped apartment from a slumlord who can't keep the plumbing functional.

You can have that experience as well in an american mid-sized city or a large exurb in an area where you can only access work or a grocery store in a private car. I have lived in such places in fact. So I'm not at all convinced that accessible transit creates slumlords or whatever the argument even is there.

You can make shitty places to live with or without cars. That's not an argument, in itself, for making them with cars.

I lived in shitty apartments that cost a king's ransom before I escaped to the suburbs. Magnasanti reminds me of those.

An extortionate real estate situation can absorb all of the benefits brought by density, and more besides. It's great for the slumlords -- or, more accurately, the real estate investment trusts representing the interests of the Magnasanti quadrillionaires -- but it sure sucks to be a drone stuck in their factorio game. Why should I want that?

Reply on news.ycombinator.com