$('#start_travel').click(function(e){
        e.preventDefault(); console.log(7777777777);
        map.travelRoute({
          origin: [40.936739, 9.174597],
          destination: [41.006362, 9.254715],
          travelMode: 'driving',
          step: function(e){
            $('#instructions').append('<li>'+e.instructions+'</li>');
            $('#instructions li:eq('+e.step_number+')').delay(450*e.step_number).fadeIn(200, function(){
              map.setCenter(e.end_location.lat(), e.end_location.lng());
              map.drawPolyline({
                path: e.path,
                strokeColor: '#131540',
                strokeOpacity: 0.6,
                strokeWeight: 6
              });
            });
          }
        });
      });