This project will support the 12th International Symposium on the theory of Traffic Flow and Transportation to be held at the University of California (Berkeley) from July 21 to July 23, 1993. In response to the congestion problem in cities, the topic of the first symposium was vehicular traffic theory. This has been the focus of the series, since the pressing need for congestion relief has not disappeared, and advanced in traffic science can open the door for solutions that do not require the construction of more and more facilities. With the same goal in mind, recent symposia have examined subjects related to traffic flow, encompassing passenger transportation modes other than the automobile. The Berkeley symposium will continue this tradition, seeking papers in intelligent vehicle/highway systems (IVHS) and freight/logistics. The distinguishing feature of this symposium series is that it deals exclusively with the scientific aspects of transportation and traffic phenomena. As such it provided the World's transportation/traffic theorists with their main forum.