title: Google Maps: Given a point, how to find all points at a given road distance?
body: <p>In my app, the GPS picks the location of the vehicle. It is then supposed to put markers at all points where the vehicle could be if it drives for 1 KM in any direction (note that the roads may fork many times within his 1KM reach).</p>
  
  <p>Can someone suggest me how to do this? Thanks in advance. </p>