Google recently add a new feature in there map this feature provide great help to Bicycling riders,Yes Biking directions is now Integrated with Google Maps, now those who are ride on bicycle also get benefits from Google Biking direction,But this service only in U.S,

Google has partnered with Rails-to-Trails (RTC), For biking directions to Google Maps.With this Google Maps now providing Rout detail of more then 150 cities of U.S. and include more than 12,000 miles of trails and bike lanes. Google says it plans to continue to add new trail information to Google Maps and is requesting feedback from riders via the “Report a Problem” tool.

with this tool user get best bicycling route and avoid the user from busy road lines, In this user will be able to directly contribute their local knowledge about trails, bike lanes and suggested routes.

for more detail you can check http://maps.google.com/biking

Source:Google official blog