This was a great learning experience. Same as the GitHub example, but now with Leaflet.
In addition we have the following in the header:
<script src="http://cdn.leafletjs.com/leaflet-0.7/leaflet.js"> </script> <script src="route.js"></script>
So the route is being read directly from a .geojson file. Although it has been renamed to route.js, and “var route = [” has been added to the beginning of the file and “]” to the end.