Hacker News new | past | comments | ask | show | jobs | submit
cjs_ac | on: USPS now offers official ZIP Code boundary polygons
Interestingly, there are no polygons for UK postcodes, because UK postcodes don’t represent a geographical area; instead, they represent one or more discrete points.
xp84 | parent | next
ZIPs don't represent areas either. They represent routes, so a collection of paths on a road map is bundled together and named with a ZIP. If you built a new house in between towns, whichever post office decides to serve it would extend one of their lines to go past your house, and then you are assigned that ZIP code. Since it's all based on their convenience, they don't pay any mind to things like city limits or even in some cases state lines.
EwanToo | parent | next
I know what you're saying, but Ordnance Survey sells the polygons anyway.

https://docs.os.uk/osngd/data-structure/administrative-and-s...

cjs_ac | root | parent
That’s naughty of them. I wonder how SW1A 1AA (Buckingham Palace) and SW1A 0AA (the House of Commons) are represented.
russdill | parent
Given how postcodes are supposed to work, this is what I would expect. Curious if many of the polygons in the data set contain more than one polygon and or if there is any overlap
kube-system | root | parent
> how postcodes are supposed to work

Not sure under what basis you think they are "supposed" to be a certain way but postal codes originated as a signifiers of areas, even in the UK.

US postal codes absolutely have overlap in area, because they do not divide land, they direct delivery routing.

russdill | root | parent
Different places have things like postal codes that mean different things, but in the US postal codes are tied to mail delivery routes.

https://web.archive.org/web/20030119031055/http://users.rcn....

kube-system | root | parent
Yes, I know that is the current way they work (...and I said it in my comment?)

My point is that postal codes aren't "supposed" to work any particular way. They work in what ever way they are specified to work at any particular point in time in any particular place.

Zip codes in the US are related to delivery routes. Prior postal codes in the US were not. UK post codes are currently hyperspecific to a single location. Previously they were not.

loading story #50433968