Using PHP and google Maps Api to work out distance between 2 post codes (UK)

Question

Hay, I wondering how to work out distance between 2 post codes using PHP and Google Maps Api.

Any one got any idea or links to examples.

Answer 1

Assuming you are looking for the geographic distance, first you need to get the latitude and longitude of your two postcodes with the Google Maps server-side geocoding services as in the following example:

$url = 'http://maps.google.com/maps/geo?q=EC3M,+UK&output=csv&sensor=false';

$data = @file_get_contents($url);

$result = explode(",", $data);

echo $result[0]; // status code
echo $result[1]; // accuracy
echo $result[2]; // latitude
echo $result[3]; // longitude

Then you can calculate the distance between the coordinates of your two postcodes by using a great-circle distance implementation such as the following:

• Snipplr - Calculate distance between two coordinates in PHP

Note that the server-side geocoding service may only be used in conjunction with displaying results on a Google map; geocoding results without displaying them on a map is prohibited by the Google Maps API Terms of Service License Restrictions.

---

UPDATE:

If you are looking for the driving distance instead of the geographical distance, note that there is no documented and approved method at the moment to access the Google Maps Directions API via an HTTP request on the server-side.

Nevertheless, an undocumented method that returns a JSON output is the following:

http://maps.google.com/maps/nav?q=from:London%20to:Dover

This will return you the driving directions, along with the total driving distance in JSON format: "meters":122977.

The format of the q parameter should be from:xxx%20to:yyy. Replace xxx and yyy with the start and destination respectively. You can use latitude and a longitude coordinates instead of full addresses:

http://maps.google.com/maps/nav?q=from:51.519894,-0.105667%20to:51.129079,1.306925

Note that not only this is undocumented, but it may also violate the restrictions 10.1 and 10.5 of the Google Maps API Terms and Conditions.

You may also be interesting in checking out the following related articles:

• Stack Overflow: Calculate driving directions using PHP?
• Getting distance using GDirections via URL
• Retrieve driving directions from google maps with server-side HTTP calls and show results with static maps for WAP
• Google Maps and Directions, REST Interface?

Answer 2

Take a look at the mailing list here:

http://groups.google.com/group/Google-Maps-API/browse_thread/thread/71e6aa2c3de66127

Once you decide if you want a straight line or driving distance you can calculate it really easily. You don't have to use PHP but there are examples.

Look at this also:

http://groups.google.com/group/google-maps-api/browse_thread/thread/d43de63d05adc62d/1a04053f39a3edf3?lnk=gst&q=calculate+distance#1a04053f39a3edf3

Answer 3

The Google Maps API is in JavaScript, not PHP. To achive what you want, turn the 2 post codes to LatLang coordinates and use the function distanceFrom to find the distance between them.

Take a look at this article for some sample code.