A GTFS file is an open specification that allows a transit agencies schedule and route information to be used by developers in a variety of applications. One of the most popular applications that uses GTFS data is Google Map’s Transit Trip Planner. County Connection’s routes are now available on google maps website and on smartphones that have google maps available. Also, the transit data is now open for developers to incorporate into their apps. Examples of transit apps include Routesy, Bay Tripper and Anystop

See a sample trip on google transit: Walnut Creek, CA to Alamo, CA
Get raw GTFS file: CCCTA GTFS on GTFA Data Exchange

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