gmaps.js

You can travel a route, step by step, this way:

map.travelRoute({
  origin: [-12.044012922866312, -77.02470665341184],
  destination: [-12.090814532191756, -77.02271108990476],
  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.drawPolyline({
        path: e.path,
        strokeColor: '#131540',
        strokeOpacity: 0.6,
        strokeWeight: 6
      });
    });
  }
});

Same as drawRoute, you must define an origin, destination and travelMode. Also, you must define the function that GMaps will call every step in the route.