Q:

Google Maps API v3: Radius parameter doesn't seem to limit autocomplete results

I'm trying to limit autocomplete results to a city by setting a country through componentRestrictions and a radius through radius, as explained here:
https://developers.google.com/maps/documentation/javascript/places
The country limitation works, not the radius unfortunately (it should limit addresses within 500 meters, in this case)! Can you help me..?
<script src="https://maps.googleapis.com/maps/api/js?&amp;sensor=false&amp;region=it&libraries=places"></script>

    <script>
    var directionsDisplay;
    var directionsService = new google.maps.DirectionsService();
    var map;

    function initialize() {
    directionsDisplay = new google.maps.DirectionsRenderer();
    var myLatlng = new google.maps.LatLng(41.88994,12.51383);

    var mapOptions = {
        zoom:16,
        mapTypeId: google.maps.MapTypeId.ROADMAP,
        center: myLatlng,
        styles: [
            {
                featureType: "poi.business",
                elementType: "labels",
                stylers: [
                        { visibility: "off" }
                ]
            }
        ]
      }

    map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
    directionsDisplay.setMap(map);
    directionsDisplay.setPanel(document.getElementById('directions-panel'));

    var input = document.getElementById('start');
var options = {
  types: ['geocode'],
  componentRestrictions: {country: 'it'},
radius: '500',
};
    var autocomplete = new google.maps.places.Autocomplete(input, options);

    autocomplete.bindTo('bounds', map);

    var marker = new google.maps.Marker({
        position: myLatlng,
        map: map,
        title: 'My Marker'
    });

    }

    function calcRoute() {
        var start = document.getElementById('start').value;
        if (start.indexOf("Roma") === -1) {
            start += ", Roma";
        }
          var end = "Via Tiburtina 500, Roma";
          var request = {
            origin:start,
            destination:end,
            travelMode: google.maps.DirectionsTravelMode.TRANSIT
          };
        directionsService.route(request, function(response, status) {
          if (status == google.maps.DirectionsStatus.OK) {
            directionsDisplay.setDirections(response);
          }
        });
    }

    google.maps.event.addDomListener(window, 'load', initialize);
    </script>

    <form onsubmit="calcRoute(); return false">
        <input type="text" id="start" name="start" placeholder="Indirizzo di partenza" style="margin-left:5px;width:200px">
        <input type="submit" value="Vai">
    </form>

        <div id="map-canvas" style="width: 927px; margin-top:5px;margin-left:5px; height: 300px; position: relative;"></div>
        <div id="directions-panel"></div>

</body>
</html>

A:

there is no radius-option for a places.Autocomplete , only a bounds-option to restrict the area

