how to get US Highway exit geocodes using Google maps API or through some other means?

For our application, we need to get all the US interstate highway exits along with their Geocodes. Can you please explain how to get these using Google Maps API or Google Local search or otherwise? So far I have no clue as to how to proceed. I greatly appreciate if you can point me in right direction.

I am looking for a free or a paid solution that is around $1000. I know there ar开发者_开发问答e people who provide geocodes. But they are out of our budget.

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You might be able to extract the data you need from openstreetmap. I shortly looked at the API they are providing, but it seems rather difficult to extract the data, although not impossible.

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It seems as though GoogleMaps doesn't have this information.

However, you could take this Excel spreadsheet from the AASHTPO and then use my free geocoder addin for Excel to find all the intersections.

Here's a sample for the first 30 exits on Route 1:

It'll be a fair bit of work, and might not be perfectly accurate, but a very good start.

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You can easily buy this data from Esri and it is very accurate stuff: http://www.esri.com/products/index.html#data_panel

I also recommend checking on https://gis.stackexchange.com/, as someone there might know a free resource.

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Tiger - US census geo data

Its totally free to download and use but it would be and adventure. I'm not sure offhand if they highway off-ramps would be in it.

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I believe that some of the Wikipedia US highway articles have geocode information in them for each exit. A microformat extractor should be able to grab them for you.