title: Determining if a point is on a road
body: <p>If I have a polyline that describes a road and I know the road width at all parts, is there an algorithm I can use to determine if a point is on the road? I'm not entirely sure how to do this since the line itself has a width of 1px.</p>
  
  <p>thanks,</p>
  
  <p>Jeff</p>