City Street Orientations Around the World

I have lived in non-grid cities all my life, but my mental map always approximates things as a grid. I occasionally then get really confused because there’s a square with five sides, or three, because roads aren’t straight or perpendicular in reality. It also affects my perception of distance because I assume parallel roads in a quadrilateral are the same length, but they’re not.

The only exception is the city I went to uni in - when I moved, I bought a map and studied it quite a lot. It’s a city I have a much stronger perception of north in, and I don’t really have the angles problem above, but I still have the distance problem.

That's a really interesting question! The two cities with which I am most familiar are San Francisco and London, and (though I'd never thought about it before) my navigational concepts of them are very different.

Getting around San Francisco is, uh, grid-like: I think in terms of "corner of X and Y", and then the relationship between myself and my destination on a coordinate plane. Getting there becomes a series of maneuvers - some of them indirect, for route-efficiency reasons (like, this street has timed lights, or this one permits left turns) - which carry with them very few (street-level, at least) visual images of the route.

London is all about pathways, a choice between more and less direct connections between my location and where I'm going. Just about every landmark and decision-point triggers a visual memory of that specific location and choice.

In San Francisco I can point fairly confidently towards a given destination, drive that direction, and find it by "feel" - eg, by intersecting one of the two cross streets on the coordinate plane. In London, I couldn't do that on a more granular than borough / neighborhood level - like, I'd know how to get to, say, Camberwell from a given location, but not in precisely which cardinal direction it lies, and once I get there I'd need to rely on landmark-based directions (or nowadays, GPS).

Navigation in London is more complex, I suppose (San Francisco has its quirks!), but the conceptual framework it requires leaves me with a more detailed and enjoyable sense of the city itself.

That's one person's experience. I'd be curious to know the extent to which it generalizes.

I'm a North American living part time in Seoul and I get lost using and cycling in small streets all the time, they turn and take random directions and my internal compass doesn't realize I'm now facing East when I thought I was walking North. I prefer cycling on smaller side streets but it's way harder to "guess" my way around detours unless I'm using a map app. I've seen delivery drivers do the same on their scooters, so I guess they feel the same unless they're very comfortable with a specific block. As in, they don't try to guess detours using some mental model of street layout: they check the map.

Also I've learned people don't give directions using cardinal directions: there's no such thing as "walk North on Seorae-ro" (or at least I was told). Which I guess makes sense since the streets on which this would be a useful mean of communicating directions are very few.

I've lived mostly in non-grid or barely-grid cities and towns. My youth was spent next to a forest.

The closest thing to grid around here is southern Helsinki, and it's also my least favorite area to navigate in. I'm always off by a block or two, and it feels like it's all the same, no landmarks or character or sense of scale.

But when I'm just a few km to the north, with diagonal streets etc, I can locate myself much easier.

I grew up in an area with a grid, and NSEW comes easily. OTOH I never cease to be appalled by people who are absolutely clueless about which direction North is. How is it possible to navigate ? Do you need a mapping app fused into your brain ?

I like having a huge mountain at hand on the horizon when I’m looking around. It is hard to find in most populations

This might sound like a dumb question, but I always thought that the streets south of Burnside were aligned with the Willamette River? I love learning about any history/geography stuff, so your comment is super interesting. I grew up outside of Portland, but have only been back a handful of times in the last decade and a half.

Great tip! I'm going to play with that idea

These things are all about intersections and the intersections they connect with. The angled portions of Seattle's downtown just doesn't have anywhere near the number of intersections as the NSEW part of the whole city.

[1] > it calculates the compass bearing from each directed edge’s origin node u to its destination node v. Now we can visualize these bearings, binned together as a histogram to get a sense of the relative frequency of the streets’ spatial orientations.

[1] https://geoffboeing.com/2018/02/street-network-orientation/

I would guess its based on the number of named streets. To the north and south of downtown you've got hundreds and hundreds of tiny streets all NESW, and not that many in downtown that are "off" the cardinal.

I looked at Warsaw and it also looks off. The "main" grid in Warsaw is the tilted one, which the article shows as secondary. There are very few streets in Warsaw that are pure N/S and E/W.

I guess this might be an artifact due to some missing data?

The plots for Chicago and Washington DC are also wrong. They both have lots of diagonal streets.

Are you referring to something on this page or data from elsewhere? The only one close is Mexico City, which wasn't Mayan, but Aztec (and others before that). It was originally an island, so maybe that had something do with the original orientation.

Precession of the equinoxes?

I feel like SF is a lot of parks and sharp 170° turns somehow nestled into a grid.

I used to live in Charlotte. Always wondered why the traffic was so uniquely awful there. Today I got my answer.

Another tidbit about Melbourne (I'm a fan): while most of greater Melbourne orients ~8 degrees clockwise of true north, the Hoddle Grid right in the middle and South Melbourne instead orient ~20 degrees counterclockwise of true north, in order to align with the adjacent stretch of the Yarra River.

Naturally, as a lifelong resident, I lean 8 degrees to the right when reading any map.

Toronto is aligned to the long straight stretch of Lake Ontario's Northern shore:

https://en.wikipedia.org/wiki/Lake_Ontario#/media/File:ISS-3...

I found a promising answer in a comment from "Nathan":

> Most of Melbourne’s grid was laid out according to magnetic north, not true north, hence the ~8 degree rotation.

Mexico City was originally on an island [1]. I wonder if, like Manhattan, that has something to do with it.

[1] https://en.wikipedia.org/wiki/Tenochtitlan#/media/File:Paint...)

Could be a variety of reasons. Maybe they point to geographic north instead of magnetic north, or it could be just simple measurement error when the city was constructed, or a natural feature of the terrain, similar to the Manhattan and Detroit graphs