Fast Geocoding of Addresses in C# with MapPoint

Everybody is into geocoding today. Once you have the latitude and longitude of a location, you can start to do some really interesting things. But the problem is that if you have a large database of addresses to geocode, the various web-based APIs are not your friend. Not only is there a lot of latency involved in each webservice call, they are also rate-limited and consequently geocoding several million or more addresses simply becomes unfeasible.

Microsoft MapPoint is a low cost, fast solution to geocoding needs. MapPoint 2010 can be found as low as $200, and an Academic edition as low as $60. MapPoint North America holds every street address in the United States. Once MapPoint is installed, it exposes a COM TypeLibrary, so using it from .NET is as simple as setting a COM reference.

Here is some sample working code to illustrate how you can geocode an address:

             MapPoint.Map map = new Map();
            MapPoint.FindResults results=  map.FindAddressResults("904 crescent pkwy", "Deland",null, "FL", "32724",                                          GeoCountry.geoCountryUnitedStates);
            object index = 1;
             MapPoint.Location loc = results.get_Item(ref index) as MapPoint.Location;

             double lat = loc.Latitude;
             double lon =loc.Longitude;
    // store in database here
           Console.WriteLine(lat.ToString( ));
           Console.WriteLine(lon.ToString());

Not only is this simple, its very fast - absolutely necessary when you have a large number of addresses to geocode.

If you do this on a Threadpool, passing in the map object in the State parameter, you can get  an address geocoded in about 12.67 milliseconds. That means you could geocode 1 million addresses in about 3 1/2 hours.