definitions of walkable city

[mindstalk]

Some thoughts on what "walkable city" means. Relatedly, my thread on 15-minute cities.

My own practical definition is what I could call grocery walkable, or maybe errand walkable. Neighborhoods where frequent errands are accessible via reasonable walks: stuff like supermarkets, pharmacies, elementary schools, public libraries, post office (maybe less important now?), laundromat/dry cleaner, dentists (more important for families, 2 trips/year/person add up), hardware store, bike store, bar/pub, etc.

"Reasonable walk" is vague, but "15 minutes" is the current fad. Personally I get antsy if my supermarket is more than 10 minutes away; OTOH a 20 minute walk to a dentist wouldn't be terrible. Growing up in Chicago, basically everything was within 5 minutes, except my schools (there were schools, I just took the bus elsewhere for reasons), and medical/dental stuff, which we didn't use and luckily didn't need much (and I have no memory of where we went for my few fillings.) Maybe we didn't have a hardware store either, though we did have a stationery store that I was sent to a lot.

Some people online have proposed what I could call job walkable, the idea that just about everyone should be able to walk to their jobs. This I consider unrealistic. Certainly there would be some jobs around the housing, and there should be housing around most jobs (with some heavy industry exceptions, for noise/emissions/danger reasons.) But, the stuff I listed above is mostly interchangeable. It doesn't matter much what pharmacy or post office or culturally-standard supermarket you go to. If you move, it's reasonable to go to whatever's closest. It also shouldn't matter much what elementary school you go to, though US reality is sadly divergent. (And, once ensconced, you might not want to pull a kid from her friends and teachers when you move. Still, the default schools should be able to serve most people.)

By contrast, many jobs are very specialized and geographically clustered. Not everyone is going to live in a short walk of a major research university, or job centers like Wall Street or whatever NY publishers gather. Even seemingly interchangeable jobs like retail or waiters can get pinned down by really liking your boss or co-workers, or gaining local experience and seniority. A family with a professor, publisher, and teen going to an art school, may find that jointly walkable housing is the null set. Even a single person can have multiple constraints like job, staying close to parents, proximity to a temple or synagogue.

On the other hand, since people do accept longer commutes for work, it could be that "job walk" could be 30 minutes or more, vs. "grocery walk" being 10 minutes.

Some other people online say things like "NYC is too big to be walkable", which seems to indicate an idea that a "walkable city" should be one you can walk across, in its whole. Maybe call this strong walkable, or complete walkable; it obviously include 'job walkable'. This was historically the norm until the invention of the streetcar... but we did invent the streetcar, bicycle, and car, so I fear the horse has long left the barn on this one.

I can imagine a related idea of simply being able to walk to the center, which might overlap with 'job walkable'. You couldn't walk to all your friends, but you could all meet downtown. Call this center walkable, perhaps. I do wonder if the largest historical cities fell here, but I have little data. Mostly I would note that this standard allows four times the area of a 'strong walkable' city.

I should note that while my thread that I linked at the beginning focuses on 15-minute walkable neighborhoods, some definitions of "15 minute city" include access to work, but also using bikes or transit, not just walking. This does expand access a lot, particularly biking: a slow bike speed of 3x walking speed means 9x the area and population. The benefit of 15 minute transit trips I'm less sure of; you're likely to use up much of 15 minutes just walking to and waiting for transit, and then it's more linear in where it takes you. Though transit development should also be more clumped around train stations, thus serving a higher proportion of trips.

Would something like a strong bikeable or center bikeable city be feasible? ...Maybe. I intend another post on the subject soon, but consider: 30 minute trip time to the center, at 4x walking speed or 20 km/hour, and density of 20,000 people/km2. Grid 'radius' of 10 km, area 2*s^2 = 200 km2, population 4 million people. Quite a sizeable city, and 'center bikeable', though the US has 15 metro areas that are more populous.

Less aggressive assumptions: 20 minutes to center (so 40 minutes on the rare occasion you have to go all the way across), 15 km/hour, 10,000 people/km2. Radius 5 km, area 50 km2, population 500,000. Small for a modern full city, but not bad.