Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Irresistible Urge to Build Cities from Scratch

bloomberg.com

Post reply on HN
Print view View original

81–90 of 122 posts

Re: The Irresistible Urge to Build Cities from Scratch

#81

Post by village-idiot »

bmsleight_ wrote: post #66
umichguy wrote: post #25

Earlier quoted context omitted.

That's kind of stupid...takes the point away from roundabouts. They're designed to keep the traffic flowing in low /medium conditions when a traffic light or stop sign would bring it to a halt otherwise. Saves on fuel etc.

Above a flow of around 3,600 pcu/hr (passenger car units) per lane, the roundabouts does not balance each direction effectively. (No gaps). Traffic lights (signals), can help improve flow further in these situations as well as giving pedestrians a safe way to cross. Part-time signals (only on a peak) can be very effective.

These areas are way below 3,600 pcu/h, maybe down in the several hundred to a thousand area. We’re talking residential side streets.

Re: The Irresistible Urge to Build Cities from Scratch

#82

Post by kybernetikos »

travisjungroth wrote: post #63
lou1306 wrote: post #12

Since nobody has cited it yet, see Christopher's Alexander "A city is not a tree" [0] for an architect's take on "natural" vs. plannes cities. [0]: http://worrydream.com/refs/Alexander%20-%20A%20City%20Is%20N...

Wow I enjoyed this essay. I'm enthusiastic about graphs, and have spent a few dinners with my girlfriend imagining designing our perfect city. I didn't expect to run into a well-written article at the intersection of those topics. For anyone interested, the ethos of our dream city is walkability. High density, mixed use buildings. The main "streets" are walking and biking only, with limited roads for service vehicles…

Vauban in Germany is somewhat like this, with the addition of trams.

Re: The Irresistible Urge to Build Cities from Scratch

#83

Post by cperciva »

barry0079 wrote: post #3

I'm a huge fan of the winding maze like structure of cities built upon the old. It's nice to be able to wander and explore. I suppose blank slate cities (like most in America) are a lot more convenient to navigate though.

I enjoy being a tourist in winding mazes. But when I want to get to work? Give me wide straight roads.

Re: The Irresistible Urge to Build Cities from Scratch

#84

Post by TeMPOraL »

Tallain wrote: post #70
EliRivers wrote: post #65

Earlier quoted context omitted.

See also "Seeing Like a State" [0] by James Scott, which discusses a number of efforts to apply conveniences for the state upon populations, including cities in which to live, with varying degrees of success. [0] https://en.wikipedia.org/wiki/Seeing_Like_a_State

See also, also, this interesting but sometimes long-winded essay / review / examination of Seeing Like a State, and similar literature[0]. It's part of a series that goes through subjects like rationalism, narcissism, and tribal knowledge. Fair warning, it's almost the length of a novel! https://samzdat.com/2017/05/22/man-as-a-rationalist-animal/

See also, also, also, Scott Alexander's take on "Seeing Like a State". Like always, both funny and insightful.

http://slatestarcodex.com/2017/03/16/book-review-seeing-like...

Re: The Irresistible Urge to Build Cities from Scratch

#86

Post by cimmanom »

kazen44 wrote: post #60
cimmanom wrote: post #58

Earlier quoted context omitted.

Even if you're not traveling from one end to another. It's great to be able to figure out where you're going without a map. I may never have been to 90th St. and 3rd Ave in Manhattan, but I know exactly where it is and how to get there from anywhere else in the grid.

as someone who lives on the other end of the continent, this system was utterly confusing to me because streets are very long in US cities. Like, alright, ending up at 90th street is relatively easy, except that i ended up at the wrong end of this street, and the walk to the correct house is 2 kilometer...

Sure, but if you already know the city just a little bit, you'll know which end 3rd ave is close to. You don't have to memorize the location of a zillion randomly named streets (where is the intersection of Grove Lane and Daffodil St?) You just have to know which direction streets increase in, which avenues increase in, and roughly how far between each. That's the benefit of the grid.

Re: The Irresistible Urge to Build Cities from Scratch

#87

Post by cimmanom »

burfog wrote: post #62
cimmanom wrote: post #56

Earlier quoted context omitted.

That doesn't compute for me - at least not in an urban environment. You're safest on the street where there are the most people; and criminals aren't going to try to break into a building if there's an audience. High foot traffic leads to safe cities. Cul-de-sacs discourage foot traffic.

That is a 100% urban mindset. I can't even imagine thinking that way. Other people find urban areas terrifying because each person present increases the threat. Crowds mean pickpockets and sometimes riots. Every person must be watched, and this is incredibly stressful. It's constant preparation for a fight-or-flight response. The non-urban mindset feels much safer with completely empty streets. The next best thing wo…

Aren't we talking about urban settings? Building cities from scratch?

Re: The Irresistible Urge to Build Cities from Scratch

#88

Post by jdmichal »

jermaustin1 wrote: post #59
jdmichal wrote: post #55

Earlier quoted context omitted.

Then there's roundabouts that look like this: https://www.google.com/maps/@27.9775503,-82.8273026,101m/dat... Multiple two-lane entrances. An inner lane that goes all the way around but cannot exit. An outer lane that has a single break between the incoming and outgoing sides of the same road. Oh, and cherry on the sundae, it's in a tourist-heavy area, so many drivers have little-to-no familiarity with it. People blo…

I'd actually say that is close to an optimal traffic circle. I'd add an even inner-er-er lane, make the outside lane a mandatory exit. If you enter in the right lane, you exit. The middle lane connects to the left of each entrance, and is able to exit at ANY of the exits, and the most inner-er lane would allow you to potentially bypass a traffic jam at another exit.

I think what you're describing is GGP's second example:

https://www.google.com/maps/@41.2981376,-73.935245,212m/data...

In which case I agree completely. And, from what I can tell, they're about the same size, so IMO this was a design miss, not a space constraint.

For me, it's all about the surprise factor. In my example, the outer lane almost goes all the way around. So you end up surprised after passing two exits and then being forced to merge to pass the next one. GGP's example is completely symmetrical, so nothing is surprising.

Re: The Irresistible Urge to Build Cities from Scratch

#89

Post by Ruthalas »

kazen44 wrote: post #60
cimmanom wrote: post #58

Earlier quoted context omitted.

Even if you're not traveling from one end to another. It's great to be able to figure out where you're going without a map. I may never have been to 90th St. and 3rd Ave in Manhattan, but I know exactly where it is and how to get there from anywhere else in the grid.

as someone who lives on the other end of the continent, this system was utterly confusing to me because streets are very long in US cities. Like, alright, ending up at 90th street is relatively easy, except that i ended up at the wrong end of this street, and the walk to the correct house is 2 kilometer...

The parent comment specified "90th and 3rd" which would give you both axes needed to avoid the mistake you describe- The specification of 3rd street helps you avoid being at the wrong end of 90th.

Re: The Irresistible Urge to Build Cities from Scratch

#90

Post by kartan »

amelius wrote: post #85

Seems like architects have similar urges as software architects :)

Yes. And they also underestimate the cost and time to build such a thing.

From the article, "The project is closely identified with President Xi Jinping, which means it’s unlikely to join a long list of Chinese “ghost cities” financed by local governments."

A lot of initiatives are started by people with an idea but without resources or knowledge to execute it.

I think that city planning is an awesome idea. I grew up in Barcelona and the results are very good (https://en.wikipedia.org/wiki/Eixample). But creating a new city from scratch is more difficult. And it is harder to get the experience to do it right as the execution of the project will take decades.

Post reply on HN