You're probably familiar with Google Maps for finding directions for routes to be driven in a car, but Google Maps now accommodates bicyclists, also, with special directions and customizable routes. Google spent years compiling information about bike lanes and paths, rails-to-trails routes, and determining bike-friendly street routes to offer its cycling directions service.
You may access turn-by-turn directions for cyclists simply by visiting Google Maps and then selecting "get directions," then selecting your mode of transportation from the menu directly below the address input boxes. Options include by car, by public transit, walking, and bicycling.
You will be presented with a map and a set of directions that avoid divided highways, and roads that do not permit bicyclists. For example, when I requested a route between two cities in my region, the directions included a good mix of urban streets, back roads, and a section of river-side bike path. The directions avoided the most direct car route, which includes a divided highway that does not allow bikes. Overall, the Google bike option provided a very good cycling route in a challenging situation.
When you choose bicycling, the Google Map changes to show bike-friendly routes. Dark green lines represent bike trails that do not permit motor vehicles. Light green lines show streets with bike lanes. Dashed green lines show additional streets recommended for cyclists. Even if there are no special cycling lanes, paths, or recommended streets for cyclists, your route will still be as bike-friendly as possible and will be shown as a blue line. Google cautions that bike routes are "in beta" and provides a "report a problem" link for cyclists' feedback on the bike route utility.
You may often be able to choose from several suggested bike routes, or you may drag-and-drop the route line to avoid an area, or to include a more scenic or pleasant option, based on your experience.
Besides turn-by-turn routing, Google offers you the option of viewing all of the bike-friendly routes in your selected region. Simply select the "bicycling" layer from the "more" menu in the map and see bike trails and lanes in light and dark green. I'm an avid cyclist, and I noticed bike lanes and trails I wasn't aware of of using this feature. Finally, this utility also lets you add a Google bike map/directions gadget to your Web page. Sounds like a must for bike shops, or any green-conscious business.
Google states it has added bike data for hundreds of (US-only so far) metro areas and is adding more constantly. Google bicycling directions work directly from Google Maps, but you may also see a video on the feature and learn more at a dedicated Google Bike maps site.