Street design and narrow streets

[mindstalk]

I spent this morning reading a bunch of blog posts on street design, which I think synergize with each other well enough to make an essay. Here goes!

20-foot streets

A few years ago I read Jeffrey Speck's Walkable City books, which had lots of interesting ideas, but the one to discuss here was about how pleasant a street was, based on the ratio of the height of the adjacent buildings to the width (from building facade to the opposite facade) of the street. With a claim that 1:6 was pretty bad, 1:1 ideal, 2:1 good. It's backed up with prospect and refuge theory (PDF), the idea that as savannah-mosaic apes, we're evolved to like the edges that give us both views and shelter (a la trees). It all seemed reasonable.

But this post from JaneJacobsJapan (JJJ) pushes back on that:

But recently, I began to notice a pattern; the best streets all fit the same basic form with regard to width and height (width between -- and height of -- building facades).

The best streets are about 20 feet wide, and the enclosing buildings are between 1.5 and 2.5 stories in height. Full Stop. No ratios.

streets wider than 20 feet must have plenty of people and plenty of trees... buildings below 1.5 stories pose a serious threat to the comfort and livability of the street

A 20 foot (6 meter) street with two story buildings is not the same as a 100 foot street with 10 story buildings. This also seems reasonable, and I hadn't been thinking along a wide scale back when I read Speck.

Half-streets and people

And that's just considering the whole space as a pedestrian space. Most likely there will be cars, especially on wider streets. And the same post goes on to raise a distinction between whole streets and two half-streets.

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Consider the woonerf above. 12-20 feet wide, shared by all users, naturally slow for cars. People walk in the middle, both sides of the street are close to hand. It is one integrated space.

OTOH, imagine a street that has two lanes of car traffic in each direction (plus sidewalks). Even without parking lanes, you will probably be much less casual about crossing this, making sure to use a crosswalk, or jaywalking nervously. A median refuge would help a lot, but still, you're crossing two lanes of traffic, then waiting for a break to cross the next two. A shop 100 feet down the block can feel more accessible than one 50 feet across the street; the street has been divided by the traffic into two half-streets. You're on this side or that side and crossing over is non-trivial.

This also ties back to his idea of 20 foot widths:

The four “half streets” [of his own examples] are defined not by two building facades, but by one building facade and one row of trees.

Viewed, this way, we can easily see that all four sections have basically the same width. Their width is the same not in the sense of a ratio, but in an absolute sense. It is about 15-20 feet.

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Another JJJ post talked about what he calls SLOW streets or Single Lane One Way. Unlike woonerfs, there is a dedicated lane for cars, but just one, flanked by wide curbless sidewalks that are guarded by bollards. One lane of slow cars is fairly easy to cross at any point, so this is still arguably one space.

There's something of a continuum; if we imagine a quasi-SLOW street, with one lane of parking added, it would be nearly as safe to cross, but the extra distance perhaps starts making the two sides feel more separate. Even without the parking, the two facades are a bit far apart, compared to the woonerf, with maybe 10 seconds to walk between them.

This leads to an idea of people-oriented vs. car-oriented streets, as talked about in Narrow Streets for People. The woonerf above is 'for' everybody but mostly for people; having lived in one such place, I can say most users were on foot or bike, not car. Similarly the SLOW street is for people, in fact devoting most of its space to people.

On the other hand, consider the Berkeley residential street where I am staying. On one side there's 5 feet (1.5 meter) of sidewalk, maybe half that of verge with occasional plants, let's say 8 feet; 16 feet with the other side. But four lanes devoted to cars: two parking, and space for two cars to squeeze past each other. 30 feet for cars, 10-16 for people. This is supposed to be "residential" -- yet 2/3 of the space is devoted to cars, clearly a more important use to the city than children playing or neighbors talking to each other.

Narrow Streets suggests that 80% of streets should be people-oriented and narrow, 8 to 25 feet wide at most (recall that that is facade to facade, not curb to curb), with the remainder more arterial-like for moving vehicles long distances. Tokyo and Osaka are a lot like that, with tons of one-lane streets, residential laneways without even cars, narrow two-lane streets ("quiet boulevards" in that link), up to full busy boulevards. By contrast, nearly all US streets are "arterial" in width and car-orientation, even when they're "residential" and not meant for lots of car traffic. Traffic hypertrophy.

Narrowing and reclamation

The urbanist Youtuber Not Just Bikes became infamous a while back for a Tweet that seemed to say people should just give up on North America, and contemplating street design per the above, I can see why. It's one thing to think about better bus systems and putting in protected bike paths, but what do you do when the very skeleton of the city is broken: streets too wide, blocks too long?

A. A. Price has some ideas in this long post, all of which is worth reading, but here I'm drawing on "Narrowing The Streets".

First, there's narrowing the car part of the street. If there are N lanes for cars (traffic parking), take some away, potentially all the way down to zero, but 1 or 2 would definitely be nice. You can use the reclaimed space for wider sidewalks, trees, or bike paths, but there's also the option of narrowing the public way itself, adding space to the adjoining properties. This a privatization of the commons, but the very problem here is that the commons is too big, unpleasant, and unproductive.

What happens then? Nothing right away, it's not like houses or other buildings can easily extend themselves to the new street edge. But at the very least, as buildings get torn down and replaced, the newer ones can take up more of the space. Also, possibly some buildings can be extended -- adding an enclosed porch to your living room, or knocking out your front wall and extending your living room. And, where there's enough depth in the front, there's also an option of building small homes or shops right there. We usually think of ADUs as a back-yard thing, but when you have front yards that are 20 or more feet deep, they can potentially be a front-yard thing, as can "Accessory Commercial Units."

(These rebuild, extend, ADU ideas also apply to simply abolishing front setback zoning, so that property owners don't have to have big lawns in front of their houses.)

Another option, particularly for wide streets, especially if you've closed them to cars entirely, is to reclaim the middle. Do you have a new 40 feet wide pedestrian mall? Run a line of trees, benches, public bathrooms, business stands or kiosks down the middle. The space will be more pleasant, and potentially even productive.

But the US doesn't just have wide streets and houses with 20 foot front setbacks. We have places with 100 or even 300 feet deep parking lots; what to do there? Price suggests "re-routing" streets. Putting my own understanding on it: imagine a stroad, with a sidewalk, then 150 feet of parking, and then a Walmart, which for simplicity's sake is assumed to stretch between two side streets. The city could eminent domain a 12-25 foot strip of land right in front of the Walmart building, and make that a new public street. Then tell Walmart "you don't have to have so much parking. You can develop or sell off that parking lot. By the way, we'll be starting a land value tax next year..." With a bit of luck, soon you'll have a new small block, facing the Walmart across from your new small street as well as accessing the original sidewalk.

(With a bit more eminent domain or buyout, you can also take some of the sidewalk-edge of the lot, to make a wider sidewalk, tree space, etc. Though, hopefully you were also narrowing the stroad while you're at it.)

I recall from the past that Price has a lot of posts about the benefits of narrow streets, but one clear one here is flexibility. If your idea of "street" means "traffic, parking, sidewalk, trees..." then it's big and you have limited options. If your idea of "street" is 12 feet that let a car squeeze past people, then you can see potential streets in a lot more places.

Cutting up blocks

Relatedly, what can you do with too-long blocks, like the ones near me, 300 by 1200 feet? You don't have a lot of great options, but if you're going to eminent domain things, taking 3 feet for a pedestrian cut-through will piss people off less than 12 feet for a car-capable street (both because you're taking less land, and because you're not letting cars past their properties)... and 12 feet for an alley or woonerf would be less intrusive than the 5 + 15 + 5 = 25 feet for two sidewalks, traffic lane, parking lane of an American "narrow street".

Of course, a 3 or even 6 foot foot path is unlikely to have businesses springing up later, even if zoning allows it; the main goal would be simply increasing access, so that blocks aren't 4 minutes long, with someone needing a 5 minute walk to get to the opposite middle of their own block.

Other resources

Alright, that's enough! Other links I didn't touch:

• Price again on narrow streets.

• JJJ has some provocative ideas about measuring prosperity as "wealth per area" via counting shops.

• The SLOW post links to Nagoya corners, a way to design the intersection of two one-lane one-way streets so that drivers are vanishingly unlikely to turn the wrong way.

• Nagano really likes putting benches on its wide sidewalks.

• Dense cities are beautiful

• Place (like 8-foot streets) vs. Non-place, including nigh-useless "green space"

• And the classic post on Japanese zoning