The paper begins by presenting motivating factors for the use of public-private partnerships in Intelligent Transportation Systems (ITS). It then explains stages of partnership development - formation, experimentation, and sustention - before introducing the seven case studies. The body of the report is a discussion of the six case studies: Heavy Vehicle Electronic License Plate, Incorporated (HELP, Inc.); North American Pre-clearance and Safety Systems (NORPASS); the I-95 Corridor Coalition; the Microelectronics and Computer Technology Corporation (MCC); the Semiconductor Manufacturing Technology Initiative (SEMATECH); and the Partnership for a New Generation of Vehicles (PNGV). For each case study there is an analysis of the program's motivating factors, formation and development, planning efforts, organizational structure, membership and funding characteristics, past and current issues of importance, interaction between partners, and keys to success or reasons for failures.