Alternative transportation concepts under study at Purdue University include the Mobility Cooperative Experiment, which involves exclusive use of mini/micro automobiles and shared used of a fleet of conventional vehicles. The experiment is designed to measure information on use patterns, driver satisfaction, vehicle performance, and vehicle durability. This paper describes the design features, hardware, and software for the on-board Data Acquisition System (DAS) designed and built in the Purdue alternative Transportation Laboratory to support these experiments. The DAS was designed to record a wide range of engine and vehicle parameters in real time, to allow driver input, to have low power consumption, and to provide two percent accuracy on all data. The design and construction of the DAS, its installation in a sample of the mini/micro fleet, the building of a data base, and analysis of the data are described.