title: Add milestones (markers) every x Km on direction
body: <p>I want to add a marker every 5 or 10 Kilometer on the polylines of the direction given by google maps api.
  something like this :</p>
  
  <p><a href="http://www.geocodezip.com/v3_polyline_example_kmmarkers_0.html" rel="nofollow">http://www.geocodezip.com/v3_polyline_example_kmmarkers_0.html</a></p>
  
  <p>but with the google direction's</p>