Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Stop using zip codes for geospatial analysis (2019)

carto.com

Post reply on HN
Print view View original

51–60 of 134 posts

Re: Stop using zip codes for geospatial analysis (2019)

#51

Post by mywittyname »

cogman10 wrote: post #20
mholt wrote: post #15

Earlier quoted context omitted.

Yeah. ZIP codes are sets in the abstract-dimensional space of carrier delivery points. I suppose you could think of them as lines, but definitely not polygons.

Zip codes (in the US) are machine readable numbers a mail sorter can use to send a parcel to the right delivery truck for final delivery. In the US, they represent the hierarchy of postal centers with the most significant digit representing the primary hub for a region and the smallest number the actual post office that will be in charge of delivering the letter (or truck if you do the extended post code). They don't…

> For some smaller population zip codes you can practically just put the name and zip code down and achieve delivery.

A 5+4 formatted ZIP code maps to just a handful of addresses. In cities with larger populations, the +4 could map to a single building, and in more sparely populated place, it might include houses on a handful of roads.

For smaller datasets, ZIP+4 might as well be a unique household identifier. I just checked a 10 million address database and 60% of entries had a unique ZIP+4, so one other bit of PII would be enough to be a 99.99% unique identifier per person.

With a geo-coded ZIP+4 database, you could locate people with a precision that's proportional to the population density of their region.

Re: Stop using zip codes for geospatial analysis (2019)

#53

Post by maxmouchet »

diggan wrote: post #34
ajfriend wrote: post #7

...and use H3 instead! https://h3geo.org/

What H3 do I belong to if my house is split between three different ones, pretty much equally? Any/all of them?

You take a smaller H3 :-) The maximum area of a resolution 15 H3 is 1 square meter, so unlikely to split a house in two.

Re: Stop using zip codes for geospatial analysis (2019)

#54

Post by VWWHFSfQ »

nitwit005 wrote: post #39
ericrallen wrote: post #28

Earlier quoted context omitted.

This is a tangent, but addresses are also way more complicated than most people realize - especially if you’re relying on a user to input a correct address or if you need to support multiple countries, somewhere with unique addresses like Queens[0], or you need to differentiate between units of a specific street address that uses something other than unit numbers for a unit designation. At that point you need somethi…

Yes, unfortunately, their assertion that everyone knows their zip code is wrong. People often write a neighboring code, and the post office just delivers it. Similar issues for city name, of course.

Very common in NYC. People will use all of "New York, NY", "Queens, NY", or "Astoria, NY" all interchangeably and the post office will still just deliver it to the same place.

Re: Stop using zip codes for geospatial analysis (2019)

#59

Post by ubermonkey »

mmmlinux wrote: post #57

Can anyone tell me why I have to enter both my city / state and a zip code. shouldn't one or the other of those plus my street address be enough information?

Web devs not using a good library that will populate the former from the latter?

Re: Stop using zip codes for geospatial analysis (2019)

#60

Post by ssl-3 »

walrus01 wrote: post #43
jonas21 wrote: post #14

ZIP codes are an emergent property of the mail delivery system. While the author might consider this a bad thing, this makes them "good enough" on multiple axes in practice. They tend to be: - Well-known (everybody knows their zip code) - Easily extracted (they're part of every address, no geocoding required) - Uniform-enough (not perfect, but in most cases close) - Granular-enough - Contiguous-enough by travel time…

In terms of "good enough", a Canadian postal code, broadly equivalent to a zip code, is much more granular and can often identify an individual apartment building, or single city block. Plenty of large office buildings in major Canadian cities also have their own postal code. The functionality of it is closer to the "Zip+4" with extension used to have a more granular routing of physical mail for USPS. https://www.can…

Sure, and in the States, ZIP+4 could once nail my postal location to a subset of 4 (of a group of 16) mailboxes within a particular set of entry doors on a particular apartment building.

But broadly speaking, nobody knows what their ZIP+4 is, while I imagine that most people in Canada know their postal code by heart.

It is interesting.

Post reply on HN