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Some locations on Google Maps are not strictly a single address and are instead denoted by a shaded area. (For example, any state or provincial park, or of specific interest to me, the Acadia University campus). Is there any way to obtain a set of longitude/latitude coordinates defining the boundary of such regions? (Again, I'm specifically interested in the aforementioned campus but I'm also interested in general solutions.)

I'm aware that this information may be more easily accessible in a data set other than Google Maps, but I'm not aware of what data set that might be, so I'll gladly accept answers that don't have anything to do with Google Maps but net approximately the same result.

(I'm sorry if this is the wrong place to be asking this question; while my first thought was to ask on Super User, it seems to have taken a turn toward tech support of late; despite being data-retrieval-oriented, this isn't a programming question, so Stack Overflow was out; and the GIS Stack Exchange seems more concerned with plotting existing data.)

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Google Maps data comes with many restrictions so isn't really suitable as a base for further use.

Although it can be of varying quality, Open Street Map (OSM) increasingly includes boundaries as well as ways (roads) and points, and is Open Data (subject to their terms of use including attribution).

The OSM data is in XML format (download link at bottom of the left column in the example) that lists the relations, ways and nodes in the boundary that was selected. In a nice simple case like that Acadia University boundary, utilities like osmtogeojson should be able to convert it into a mapping format like geojson, but it might struggle with a more complex nested boundary.

By comparing Google Maps with the OSM data you'll see there are some differences with the campus boundaries (especially north of Hwy 1 / Main St). It's debatable which is more accurate, the official campus map doesn't show any boundaries but does include (for example) buildings west of Westwood that neither Google or OSM include within the campus.

For a more general solution, many countries now have open data boundary files online, such as GeoBase for Canada. These are more likely just to be government admin areas (provinces, municipalities, ridings and so on), and can be a large amount of data to deal with.

  • Thanks, this is exactly what I'm looking for. Precision isn't of the essence, but I wanted something better than stabbing my cursor at the page and hoping the point I landed on was close. As I needed latitude/longitude positions for all the points in the way, I created a quick and dirty script to scrape them. – Mr. DOS Feb 13 '14 at 3:49
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The US Census provides a lot of Shapefiles (Tiger/Line Products) which would aid in some of the features you may be looking to define boundaries for:

http://www.census.gov/geo/maps-data/data/tiger-line.html

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