cara membuat jalan alternative google maps menggunakan javascript

cara membuat jalan alternative google maps menggunakan javascript

directionsService.route(
    directionsRequest,
    function (response, status) {
        if (status == google.maps.DirectionsStatus.OK) {
            for (var i = 0, len = response.routes.length; i < len; i++) {
                new google.maps.DirectionsRenderer({
                    map: mapObject,
                    directions: response,
                    routeIndex: i
                });
            }
        } else {
            $("#error").append("Unable to retrieve your route<br />");
        }
    }
);