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I have recently noticed the nice dashes that Google Places puts around cities, regions, states etc. I've been hunting around in the Google Maps API and the Google Places API trying to find out how to access the information thus displayed, without success.

I've discovered that Twitter has a nice API for this and I would be tempted to use that instead of Google's, but I worry that the lines that Google draw and the lines that Twitter draw may not correspond.

Is it safe to assume that both companies are using the same data? If not, where do I find the appropriate API information for the Google implementation?

Alternatively, where do I find the geodata they're both using?

PLEASE NOTE I'm asking about this in the context of Australian geodata. Do Google and Twitter use the same or different resources?

bugmagnet
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4 Answers4

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Most info is at the Census Bureau website. The state and county boundaries are in the section about TIGER files.

Drilling further, the Census Bureau subdivides counties into census tracts, and tracts in census blockgroups, which in turn contain a set of blocks like the one you live in. While states and counties overlap the administrative divisions we know, tracts and blockgroups do not.

There are boundaries defined by different government agencies which are not hierarchically connected to a census entity but are instead in a parallel taxonomy. This is the case of the Metropolitan and Micropolitan Statistical Areas defined for budgeting purposes.

Google is probably (but I'm not sure) displaying Urban Areas, which is another taxonomy grouped on a population-density criteria. An Urban Area can exist in more than one census tract or even more than one county at the same time. There are relation files that map the entities to other entity families.

Finally, there are some "entities" that arent geometrical but popular culture considers them to be. This is the case of USPS Zipcodes, that do not amount for a geometry and have a very loose mapping to real geographical entities.

For any attempt to draw border lines in an application, states and counties are 100% safe to draw. For smaller entities, I'd reccomend sticking to census tracts and census blockgroup boundaries. The other entities have blurry edges, evolving definitions, contradicting boundaries and should be taken as a mere reference.

ffflabs
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  • Thanks. Good info ... for USA. However, I'm in Australia. – bugmagnet Apr 07 '14 at 15:55
  • Oh... in that case I don't know. Each country has its own hierarchies. – ffflabs Apr 07 '14 at 17:53
  • Ok, so who can tell me where those hierarchies are stored? – bugmagnet Apr 08 '14 at 06:31
  • It seems they have the info available to download as ESRI shapefiles [ASGC Digital Boundaries](http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/1259.0.30.001July%202011) – ffflabs Apr 08 '14 at 10:26
  • Yes, have seen all this stuff already (thanks, Google) but can anyone tell me one way or the other whether Google and Twitter both use this data. It matters a lot (to me, at least) if they are using different datasets. – bugmagnet Apr 09 '14 at 02:53
  • I don't think twitter is actually using the same boundary model that google uses. Instead, I believe twitter performs a reverse geocoding against a place database (like [GeoNames](http://www.geonames.org/), for example) to return a place name for a given coordinate pair. This means some points on earth do not belong to a place, and place geometries are not topologically related surfaces. – ffflabs Apr 09 '14 at 17:02
  • @boost: Why don't you send the companies an e-mail and ask? Then compare the responses from Google and Twitter. – d3dave Apr 14 '14 at 00:58
  • @wiz3kid: 53 years old and I didn't think of that ... d'oh! – bugmagnet Apr 14 '14 at 04:24
  • Ok, have written directly to Google and Twitter. Let's see what comes of it. – bugmagnet Apr 14 '14 at 14:11
  • Meanwhile it looks like @amenadiel is going to get the bounty even though his answer isn't quite 'there' – bugmagnet Apr 15 '14 at 02:08
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All companies as Google, Microsoft and Apple got this free vector and raster map GeoJSON data built through collaboration of many volunteers supported by NACIS (North American Cartographic Information Society).

Project: https://github.com/nvkelso/natural-earth-vector/tree/master/geojson

Website: http://www.naturalearthdata.com/

Fernando Santucci
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via Barry Hunter

 where political boundaries are derived from,

May want to do some digging in Map Maker

whether it is possible to derive polygons for such boundaries from Google,

In short no. There isnt an API for that. 

Also, does anyone at Google know whether Twitter data is the same or different?

Almost certainly different.

As for Twitter I'm still waiting on a response to my question.

bugmagnet
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think this is what you need it uses US Census as repository: US Zipcode Boundaries API: https://www.mashape.com/vanitysoft/boundaries-io

Above API shows US Boundaries(GeoJson) by zipcode,city, and state. you should use the API programatically to handle large results.enter image description here

Jeryl Cook
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