Google has created a new feature in Google Maps called mapplets. It is still in preview, but you can see it at http://maps.google.com/preview. It looks almost the same as the regular Google Maps but it has an extra tab called Mapplets. The Google Mapplets are still in development stage and you also need a Google account to use them.
You can add your own Mapplets by clicking on the Mapplets tab and then selecting Add Content. Once the page changes to "Google Mapplets Gallery" you can add one or more mapplets to your Map content. At the top of the page you can "Search Google Map Contents". Search for "Boulder Bike" and you will see that the search result includes "Boulder Bike Paths". Add that to the map and enjoy.
Once the Mapplets hit the mainstream, though, having the Boulder Bike Paths Mapplet will allow a user to overlay the bike path network over any Google Maps search results.