[vvillena]

American cities aren't optimized for navigation, they are optimized for sales. A parcel of terrain is easier to sell when it's not that different from the one alongside it. Selling a house is also easier when there's no quirky features or strange floorplans.

[eesmith]

I think it's hard to look at a grid system and say that it's optimized for sales.

US urban planning in the late 1800s and early 1900s "emphasized a grid plan, partly out of extensive reliance on foot, horse and streetcars for transportation. In such earlier urban development, alleys were included to allow for deliveries of soiled supplies, such as coal, to the rear of houses which are now heated by electricity, piped natural gas or oil." - https://en.wikipedia.org/wiki/Dead_end_(street)#Suburban_use...

Sure, you might argue that people purchased those houses because of the benefits of the grid system, and hence (indirectly) optimized for sales. But that same Wikipedia page points out that post-war construction in the US emphasized cul-de-sac and crescent streets.

> "Real estate developers prefer culs-de-sac because they allow builders to fit more houses into oddly shaped tracts of land and facilitate building to the edges of rivers and property lines.[10] They also choose these discontinuous network patterns of cul-de-sac and loop streets because of the often significant economies in infrastructure costs compared to the grid plan. ... The desirability of the cul-de-sac street type among home buyers is implied by the evidence that they often pay up to a 20% premium for a home on such a street, according to one study.[10] This could be because there is considerably less passing traffic, resulting in less noise and reduced actual or perceived risk, increasing the sense of tranquility."

In other words, cul-de-sacs optimize sales, not grid patterns, and "quirky features or strange floorplans" of non-grid plats don't seem to be a problem - quite the opposite.

I believe Joseph Smith's 'Plat of the City of Zion' influence on Salt Lake City's shows that the grid system of SLC was not specifically optimized for sales, and indeed was partially designed for navigation. At the very least, you know were you are with respect to the Temple.

[jacobush]

Cul-de-sacs decrease criminality too. If you go down a cul-de-sacs to do recon, you look out of place.

[cimmanom]

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.

[jacobush]

While I can buy that a cul-de-sac is not always beneficial, to me it's not hard to buy that it can lower burglary. Also if high foot traffic leads to safer cities depends a lot on how likely these people are to help out in any way. In some cities I'd fear onlookers are more likely to contribute to a robbery than help me out.

First, where the cul-de-sacs are in my town, there is virtually no violent crime. (Violence directed towards persons.)

However, there is a decent amount of burglary and break-ins. Now, if you are going to do that for profit, you'll typically need some form of transportation to get away swiftly before the police gets on your track. Either a moped or a car, depending on the bulk of the loot you are planning on acquiring.

Before a burglary, you'll want to do recon. I can tell you, from the point of view of someone who was looking for property to buy, driving or walking down these cul-de-sacs will get you noted. People know each other there, if not by name, then by looks and what their car looks like. As an outsider, having your license plate number written down or a being snapped with a cell phone camera is par for the course.

Also, some of the suburban cul-de-sacs would have almost no foot traffic not intended for that street anyway, when the street in question is on a leaf or twig.

[eesmith]

The Wikipedia article I linked references a report, which I also linked to, and summarizes the "higher foot traffic" more specifically as "local movement is beneficial, larger scale movement not so".

Presumably, local people are more likely to help out.

(As an aside, domestic violence is highly under-reported. It's almost certain violence directed towards persons occurs in some of those cul-de-sac houses.)

I've not had that experience walking down culs-de-sac.

In any case, it sounds like an easy way to do recon would be to walk a dog through the neighborhood. Making sure to pick up. Or put a camera mount on your roof and slap a sticker on the side saying "Google Street View Vehicle."

[burfog]

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 would be just cars.

[bobthepanda]

Conversely, if someone mugs you in the cul-de-sac and no one is there to hear you scream, are you really safe? How can you get help? There may be people driving by, but they probably only hear whatever's going on for a split second as they drive past you in a sealed car.

There are crowds everywhere there is economic activity. No one thinks the shopping mall or the beach or the park is the next coming of the Bolsheviks or the next Ferguson; that's all purely suburban American hysteria.

[eesmith]

Please define "urban".

Cul-de-sac layouts are usually in suburban regions. Is that included in 'urban'? Or are you comparing urban cores to exurbs or rural regions?

I've walked outside at 1am in a city with no one else on the streets. I've walked at 1am in another city with a lot of people on the streets. I can tell you that I felt safer when there were more people on the street than just me. Which would make you feel safer?

FWIW, "high foot traffic" does not only mean "crowds". Neighbors walking by every few minutes would count as high traffic.

To give more concrete numbers, https://spacesyntax.com/wp-content/uploads/2011/11/Hillier-S... concerns this exact topic. The author writes "Mean pedestrian movement [for road] segments without retail the rate is 158.476 [per hour] for 317 segments", where a 'segment' is the section of street between intersections, in this case, in London.

That's roughly 2-4 people on the street at any one time - hardly a crowd that would lead to a riot!

On streets with retail, it's 640, or about 10-20 people at any one time.

[burfog]

I think all of us (you, me, cimmanom) are assuming that cul-de-sac layouts are not urban.

Due to bad navigation, I walked through a bad area of western San Francisco on July 4 during mid day and then again on July 5 at around 2 AM. As a non-urban person I might be clueless, but I felt a lot less terrified with the deserted streets at 2 AM. Fewer people means fewer threats. I don't assume bystanders will somehow help me.

The idea that "criminals aren't going to try to break into a building if there's an audience" was proven wrong right after I left, with the Wells Fargo museum robbery happening in broad daylight with a crowd and a traffic jam.

[cimmanom]

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

[gowld]

That is a 100% male driver mindset. A female mindset on a deserted road is constant preparation for assault. A bicyclist or pedestrian on a road full of cars is in constant preparation for a collision.

[burfog]

No. Being female only changes the nature of likely threats, slightly.

Assume the example person is walking. Fear of crowds is the norm for people with a rural/suburban mindset. Evidently, people with an urban mindset actually feel safer in crowds, which is difficult for me to wrap my head around.

The deserted road is safe, aside from wild animals.

In a crowd, the more extreme rural/suburban people would be keeping their hand near a concealed weapon. I suppose this feeling might be alien to a person accustomed to city life.

The above plays a role in the fact that rural/suburban people without jobs are often hesitant to move to cities. The stress would take a toll on such people.

[eesmith]

The Wikipedia page has several paragraphs on "this disputed issue", describing both pro- and con- views. One cited paper concludes "relative affluence and the number of neighbours has a greater effect than either being on a cul-de-sac or being on a through street".

[beaconstudios]

so if living on a cul-de-sac predicts for relative affluence, it may be a proxy for lower crime?

[eesmith]

... no? At least, that's not what I inferred from the Wikipedia article.

If you want to dig into the details, the report is at https://spacesyntax.com/wp-content/uploads/2011/11/Hillier-S... . A quick search finds the following in the conclusion section:

> Cul de sacs or grids?

> The principle that larger the numbers of dwellings on the street segment reduces the risk of burglary, applies both to cul de sacs and grid like layouts. Small number of dwellings in a cul de sac are vulnerable, especially if the dwelling are affluent.