I observe that being able to build great infrastructure is when you have the good fortune of having financial, political, and social forces that incentivize it. That doesn't occur a lot these days. It also takes foresight to build up a reserve of these, because projects are so easily cancelled.

One surprising thing I learned about the Japanese (Tokyo) metro system and its complexity, and yet punctuality and adherence to precise schedules:

The Tokyo metro system didn't get as good as it is because of someone's simple desire to have a really nice metro system, or some theoretical love of schedules.

It became so well-timed and complex because it had to be. Due to the constraints of land and existing infrastructure, there was no other way to serve as many people as demanded train service than to build stacks and stacks of rail networks, and have them operate (and interoperate between lines efficiently) down to the second -- in order to be able to cram that many trains into one space.

Versus in other places, people would say, those requirements are so ridiculous, there's no way a metro system could ever be built to work!

Sometimes, the constraints produce progress. (Of course, this is subsidized up the wazoo in Japan, but not crazily compared to other major metro areas.)

A lot of this feels "citation needed". Unlike streets, building software that can scale up is not necessarily more costly - often it means a cleaner architecture that yields benefits from day 1. The examples of cut-and-cover BART and freeway widening are in direct opposition to each other - sometimes we use a cheap construction approach that involves disruption, or an expensive one that reduces it. It's telling that the author doesn't even see anything unusual in the idea that no expense should be spared for the roads, but subways should be built as cheaply as possible.

I wonder what the authors thoughts are on the Moscow Metro. Schematic map: https://upload.wikimedia.org/wikipedia/commons/1/14/Moscow_m...

Seems like a bunch of concentric circles with lines going away from the center.

I have never been to Moscow, but it seems like an interesting success story of planning infrastructure projects properly.

All these comments are about subways when the article is actually about software engineering.

You all missed the point.

> You can't easily build infrastructure where it's crowded, and you can't afford to build infrastructure where it's not crowded.

Isn't "easily" and affordable" pretty much the same thing? Surely you can build subway pretty much anywhere, it will just cost you where it's crowded. He is basically saying you can't afford to build infrastructure anywhere - no matter if crowded or not crowded, which is quite dumb.

> Many of these massive projects have incurred various costs and challenges. In the 1950s and 1960s, the Fillmore redevelopment targeted a largely black part of town. A 36-block area was torn down including housing, a distinct lifestyle, and a world-famous jazz community. Most of the previous occupants could not afford to return.

> In many cases, these huge, multi-decade redevelopment projects bring new life to part of a city, but sometimes we can't foresee what we're going to lose.

This is disingenuous, and shows how little the author understands about the history of American urban development. In many cases the purpose of redevelopment in US urban environments has been to push out people of color. To say that gentrification was an unforeseen consequence of redevelopment is just wrong. Gentrification is often the entire point of redevelopment by city officials.

They should read The Death and Life of Great American Cities by Jane Jacobs or read The Power Broker by Robert Caro.

To be completely serious, this article reads like someone had some ideas about urban development, did absolutely no research, and then talked about those ideas like they were some kind of expert. I don't understand why the ACM would publish something like this.