"The Google Maps API is great, but it doesn’t have aneasy way to export data in GPXformat. This bookmarklet is my attempt at a hack to get information out of Google Maps and into GPX, suitable for loading on a GPS.
This bookmarklet can create a GPX file based on driving directions, an address search or a local search. The GPX file will contain a route, a single waypoint, or up to ten waypoints, respectively. The code for extracting waypoints from local search originally came from this page."
The ITN Convertor Editors default map is Google Maps with options to use many other map sources. You can open, save or convert routes and itineraries in all the popular GPS route planner formats or POI files.
Log into Google, open Google Maps. Click on My Places. Create your own map with your designed route on it. Click on KML. You now have a downloaded route file. Loads of online converters will convert a KML file into GPX, ITN, CSV, whatever you need.