Bicycle Routing Engine is an innovative and open bike mapping system specially designed to find flat, safe, and fast bike routes anywhere in the SF Bay Area. The routing engine is based on graphserver, an open-source python multimodal trip planner. The underlying map data is from OpenStreetMap, with elevation data from USGS.
I worked with the creator of graphserver to implement the contraction hierarchies technique on bikesy to precompute routes for nine instances with three different hill-tolerances and three different safety tolerances. The routing engine has an easy to use API which has been used by the BayTripper iPhone app to include bike routes.
Visit Bikesy | Bikesy API | Bikesy routing engine source