Different search results Zip vs City, State

[+sc_dragonflies]

Can someone explain why I get such different results when I do a search by Zip code (small town, only one Zip) vs when I search using location City, State? (To see what I mean, try searching Zip code 28782 5 mile radius, then try searching Tryon, NC 5 mile radius)

[+niraD]

The system translates zip codes and city names into coordinates when it does a search. The zip code and the city name don't translate to the same coordinates.

 

My understanding is that zip codes translate to a point roughly in the geographic center of the area covered by the zip code. Cities usually translate into the location of city hall or a similar "town center" location.

[+Walts Hunting]

That is especially true in rurul areas. My post office is Rescue, CA but no such town actually exists. Actually there are only two cities in the whole county.

[knowschad]

Can someone explain why I get such different results when I do a search by Zip code (small town, only one Zip) vs when I search using location City, State? (To see what I mean, try searching Zip code 28782 5 mile radius, then try searching Tryon, NC 5 mile radius)

 

This is actually a Google problem. This is actually Google providing those results. The site uses the Google API to get its location data. You can see it yourself by first Googling the zip code and checking the map and then searching Tryon, NC and view that map.

 

Edited to remove "problem" because it could well be that Google is correct about the location of the zip code.

Edited August 22, 2011 by knowschad

[+John in Valley Forge]

 

This is actually a Google problem.

 

Is it actually a problem or just an anomaly?

[knowschad]

This is actually a Google problem.

 

Is it actually a problem or just an anomaly?

 

You posted before my edit.

[+John in Valley Forge]

This is actually a Google problem.

 

Is it actually a problem or just an anomaly?

 

You posted before my edit.

 

LOL, the dog was napping.

[+John in Valley Forge]

Can someone explain why I get such different results when I do a search by Zip code (small town, only one Zip) vs when I search using location City, State? (To see what I mean, try searching Zip code 28782 5 mile radius, then try searching Tryon, NC 5 mile radius)

 

This is actually a Google problem. This is actually Google providing those results. The site uses the Google API to get its location data. You can see it yourself by first Googling the zip code and checking the map and then searching Tryon, NC and view that map.

 

Edited to remove "problem" because it could well be that Google is correct about the location of the zip code.

 

On a serious note, I do a lot of desktop demographic studies at work and have long ago reconciled the differences between towns and zip codes.

 

In my own town, there is a neighborhood that was somewhat cut off from the rest of the town when the state rerouted a highway. That neighborhood is serviced by the next post office over, just because logistically it makes a lot more sense for the mail trucks. So although they are in our town, pay taxes to us and go to our school, the have the zip code of the next town over.

 

 

[+GeoGeeBee]

Can someone explain why I get such different results when I do a search by Zip code (small town, only one Zip) vs when I search using location City, State? (To see what I mean, try searching Zip code 28782 5 mile radius, then try searching Tryon, NC 5 mile radius)

 

This is actually a Google problem. This is actually Google providing those results. The site uses the Google API to get its location data. You can see it yourself by first Googling the zip code and checking the map and then searching Tryon, NC and view that map.

 

Edited to remove "problem" because it could well be that Google is correct about the location of the zip code.

28752 is a really big zip code. While it's true that all of Tryon, NC is in the 28752 zip code, it is also true that according to the USPS database, the zip code is centered on Marion, NC. Those two towns are about 50 miles apart.

[+TheAlabamaRambler]

Irondale is a small city on the border of Birmingham, a large city. In fact my street has two names, Monticello where I live and two blocks up the street at the Birmingham / Irondale city line the spelling changes to Montecello. But my zip code, 35210 includes parts of both cites as well as some unincorporated county land, so mapping is a real problem here. Every map you look at gets it differently. Some think I am in Birmingham, others think I am in Irondale, and mail sent to 35210 may end up at either post office.

[+humboldt flier]

The quick and dirty:

 

The "Postal Centroid" is typically the center point of a particular zip code. The centroid is rarely, if ever, co-incident with the post office associated with a particular zip code.