iphone - Road distance,Actual distance between two places

Question

I want to calculate the driving distance between two locations [the user's specified locations], before user starts the driving. I used many formulas and getDistanceFrom in CLLocation also, but I am not able to get the perfect the driving distance between those locations.

There is much difference in actual and calculated distance.

Please help me to calculate the driving distance between two locations. How can I use Google Maps API to calculate the driving distance ?

I have already use the regexkitlite to show the road path on Google Maps between the two place. However I can't calculated the path distance.

If you have any code/link, please send it to me.

Thanks in advance....

Answer 1

See directions API of Google Maps

You have just to make a HTTP request:
http://maps.googleapis.com/maps/api/directions/output?parameters

Answer could be json or xml. You will find the distance in the answer