This proceedings volume consists of selected papers presented at the Ninth Int- national Conference on Computer-Aided Scheduling of Public Transport (CASPT 2004), which was held at the Hilton San Diego Resort and Conference Center in San Diego, California, USA, from August 9-11, 2004. The CASPT 2004 conference is the continuation of a series of international workshops and conferences prese- ing recent research and progress in computer-aided scheduling in public transport. Previous workshops and conferences were held in: • Chicago (1975) • Leeds (1980) • Montreal (1983 and 1990) • Hamburg (1987) • Lisbon (1993) • Cambridge, Mass. (1997) 1 • Berlin (2000) 1 While there were no formal proceedings for the ?rst workshop (only pre-prints were d- tributedtoparticipants),thesubsequentworkshopsandconferenceswerewelldocumented: Wren, A. (ed.) (1981). Computer Scheduling of Public Transport, North-Holland, - sterdam. Rousseau, J.-M. (ed.) (1985). Computer Scheduling of Public Transport 2, North- Holland, Amsterdam. Daduna, J.R. and A. Wren (eds.) (1988). Computer-Aided Transit Scheduling, Lecture Notes in Economics and Mathematical Systems 308, Springer, Berlin. Desrochers, M. and J.-M. Rousseau (eds.) (1992). Computer-Aided Transit Scheduling, Lecture Notes in Economics and Mathematical Systems 386, Springer, Berlin. Daduna, J.R., I. Branco, and J.M.P. Paixao ˜ (eds.) (1995). Computer-Aided Transit Scheduling, Lectures Notes in Economics and Mathematical Systems 430, Springer, Berlin. Wilson, N.H.M. (ed.) (1999). Computer-Aided Transit Scheduling, Lecture Notes in Economics and Mathematical Systems 471, Springer, Berlin.