Transit directions at global scale
  A novel approach to integrated ground and air public transport journey planning, operating at continent scale. Flexible date search, prerequisite for long distance trips given their typical low and irregular service frequencies, is core functionality. The algorithm is especially suited for irregular and poorly structured networks. Almost all of the described functionality is implemented in a working prototype. Using ground transport only, the system is on par with Google Transit on random country-wide trips in the US. 
Joris van der Geer
cs.OH