This is an example project demonstrating how to draw a polyline inside an MKMapView that continues to display correctly even as a user pinches and zooms the map. It incorporates and expands upon ideas from Craig Spitzkoff and Nicolas Neubauer.
For more information, see:
For information on the inspiration behind this original work, see:
http://spitzkoff.com/craig/?p=65 http://pixelfehler.nicolas-neubauer.de/2009/09/04/mapkit-google-maps-iphone-and-drawing-routes-or-polylines/