University of California Transportation Center

The impressive movement forward of transportation modeling and simulation emerges from three related but distinct sources. The first source is a fundamental change in planning practice that one could name dynamic planning practice to indicate the existence of bi-directional time (from the past to the future and from the future to today), as well as, assessment cycles and adjustments taking place within the short term, medium term, and long term horizons. These cycles are also bidirectional in time. This source contains three fundamental directions of practice that are inventory creation and maintenance, strategy measurement and evaluation, forecasting and backcasting. The second source is a vision that generates the substantive problems that we need to solve and the specific policies we need to examine. It is named sustainable and green visions. Problems and solutions in this general area motivate and inspire contemporary substance and content of policies throughout the world. One can identify three complementary and mutually strengthening directions in the economy, environment, and society that are the three fundamental pillars of sustainability. The third source is the never ending research for improved understanding of the world surrounding us. This source is named new research and technology to capture the most important elements of new discovery and new techniques enabling new discovery but also modeling and simulation. Key directions of inquiry within research and technology are theory building, modeling and simulation, and enabling technologies.