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How can I find the closest intersection of the street I have coordinates of?

For instance, say I have street A running from south to north that is crossed by street X on the north and by street Y on the south.

Does the Google Maps API allow for finding coordinates of the nearest crossroad (either X or Y) of street A? I couldn't find it mentioned anywhere.

PS: The only solution I am aware of is to guess the lowest number and the highest number of building on the street A and to draw polyline between them. I am not sure about this though.

GEOCHET
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dusoft
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  • I wonder if you could hack GDirections to do this? – dotjoe Feb 16 '09 at 21:59
  • I am not sure, I ill have to dive in GDirections API to find out, but I have searched for the answer (both google and google maps support groups) and nobody really seem to know, if this is possible. – dusoft Feb 17 '09 at 11:42
  • I was thinking you could get the walking directions to two points so that it would force you to turn on the first crossroad. But, i doubt this would be reliable. Is there a google maps search operator like "nearest intersection" or something? – dotjoe Feb 17 '09 at 16:27
  • no, there is not. it would help if there was a function to provide an array of coordinates of the nearest intersections. – dusoft Feb 19 '09 at 15:56

2 Answers2

1

[see comments above]

unfortunately, no. even with gdirections, there is no way to locate the beginning and end of the street (coordinates). I have solved it by using the hack proposed above: looping over building numbers from 1 to XXX.

if accuracy is 6 for a while (8 = building number, 7=intersection, 6 = approximate address only) that means no new numbers exist. so i just take first point (lat/long), middle one and the last one (all with accuracy 8) and create path between them. this however sometimes only provides only a part of the street as other parts are either without any buildings or google does not have further data :(

dusoft
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0

You might consider using the TIGER data from the USGS. You can get that information from there, but it's not as easy to play with as the Google data.

GEOCHET
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Adam Davis
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  • thanks, Adam, but unfortunately I am not mapping US. that's also hy accuracy is somehow limited (8 is the highest I can get at some streets). – dusoft Feb 18 '09 at 14:22