However, there currently isn’t a way to get display the transit or bike map layer. However, Google Maps allows you to create your own tile layer and load in into the map. It’s not too difficult to create your own custom tile layer and actually refer to the actual bike map or transit map tiles and load them directly from Google.

The URL template you need for getting bike maps is:

http://mt1.google.com/vt/lyrs=m@121,bike&hl=en&x={X}&y={Y}&z={Z}

and for transit maps:

http://mt1.google.com/vt/lyrs=m@121,transit|vm:1&hl=en&opts=r&x={X}&y={Y}&z={Z}

To create your own tile layer, use one of the URL templates above:

function initialize() {
  var map = new GMap2(document.getElementById("map_canvas"));
  map.setCenter(new GLatLng(37.880002, -122.189941), 11);

  //Create new Tile Layer
  var gTileUrlTemplate = 'http://mt1.google.com/vt/lyrs=m@121,bike&hl=en&x={X}&y={Y}&z={Z}';
  var tileLayerOverlay = new GTileLayerOverlay(
    new GTileLayer(null, null, null, {
      tileUrlTemplate: gTileUrlTemplate,
      isPng:true,
      opacity:0.8
    })
  );
  map.addOverlay(tileLayerOverlay);
  }

These URLs could change at any time, so there is no guarantee that this won’t break. You can see this in action at whereisbart.com

Armed with a 1353 page environmental impact report that claims biking is good for environment, the city is now gearing up to proceed with much needed improvements. The public comment period ended on Jan 13, 2009 which might mean at some point this year we’ll see the beginnings of 34 miles of bike lanes, improved intersections, signage and much more.

Meanwhile, there has been talk of eliminating car traffic on Market Street, eliminating bike lanes on part of Market Street (what?), and charging all vehicle traffic in the central part of the city. Its going to be interesting to follow all of this.