San Francisco BikeMapper
The San Francisco BikeMapper uses Google Maps to provide biking directions using all existing Class I, II and III bike routes in San Francisco, southern Marin County and northern San Mateo County.
Using the BikeMapper it is possible to find the best bike route for your trip with turn-by-turn directions. To get directions you just need to enter your starting point and destination. You can also select to get the shortest bike friendly route or, importantly for hilly San Francisco, the flattest bike friendly route.
The results of your search are then displayed on the map and the turn-by-turn directions are listed in the map sidebar. Details of the route are also provided, such as the length of the journey, the estimated time and the carbon emissions saved.