TRANSPORTATION PLANNING AND MODELING. IN: HANDBOOK OF TRANSPORTATION ENGINEERING

More than at any other time during the past decade, it has been observed that there is a clear shift in transportation policies away from construction of new facilities towards a more efficient management of existing transportation systems in order to meet the ever-increasing transportation demand. Contrary to widespread belief, this change in direction has not eliminated projects for new highway and projects for major maintenance and reconstruction of existing highways. Every year billions of U.S. dollars are allocated to new transportation facilities. This chapter describes how there is a general shift toward optimal management of existing facilities and strategic improvements at specific transportation system components that are considered to be critical interventions in a system of interconnected and mutually influencing facilities. In fact, in the United States some of the congressional appropriation recipients and their assets play a critical role in the functioning of the national transportation system and its interfacing play a critical role in the functioning of the national transportation systems and its interfacing state systems. Independent of role, location and perceived need for assessment, the overall goal of fund allocation is to maximize the performance of the transportation system in its entirety and avoid major new infrastructure building initiatives. In parallel, a movement toward policy actions and large investments has been observed that aims to protect the environment. These policy actions also view the world surrounding us as an ecosystem, placing more emphasis on its overall survival by examining direct and indirect policy actions.