Questo violino potrebbe aiutare:
// init map
var myOptions = {
mapTypeId: google.maps.MapTypeId.ROADMAP
};
var map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
// init directions service
var dirService = new google.maps.DirectionsService();
var dirRenderer = new google.maps.DirectionsRenderer({suppressMarkers: true});
dirRenderer.setMap(map);
// highlight a street
var request = {
origin: "48.1252,11.5407",
destination: "48.13376,11.5535",
//waypoints: [{location:"48.12449,11.5536"}, {location:"48.12515,11.5569"}],
travelMode: google.maps.TravelMode.DRIVING
};
dirService.route(request, function(result, status) {
if (status == google.maps.DirectionsStatus.OK) {
dirRenderer.setDirections(result);
}
});
http://jsfiddle.net/HG7SV/15/
Opzioni aggiuntive:
https://developers.google.com/maps/documentation/javascript/directions