Transportation engineering is the "application of scientific principles to the planning, design, operation and management of transportation systems. The transportation field practiced by civil engineers is inherently multi-disciplinary, overlapping such diverse fields as economics, psychology, geography, city planning, public administration, political science, industrial engineering and electrical engineering. In addition, major theoretical contributions to transportation engineering have been made by people with backgrounds in physics and mathematics.
This breadth of interaction with other disciplines stems from the fact that the scope of transportation engineering is determined more by society’s need to provide an adequate transportation system by the backgrounds of its practitioners. Thus it involves synthesis of several different intellectual perspectives and scientific knowledge bases to solve perceived technical, economic, social and environmental problems".
(Source: Quoted in Introduction to transportation engineering. TA 1145 B36 2002, 3rd floor, Circulation Section)