Transportation Engineering is a branch of Civil Engineering. As its name implies, this Field deals with various aspects of transportation: roads, highways, airports, railroads, etc. Transportation is one of the most rapidly changing aspects of cities today. New highways, expanded airports...... And with the coming switch-over to driverless cars and trucks, this Field will continue to be in great demand for many years to come.
Transport engineering is the application of technology and scientific principles to the planning, functional design, operation and management of facilities for any mode of transportation in order to provide for the safe, efficient, rapid, comfortable, convenient, economical, and environmentally compatible movement of people and goods transport.
Transportation engineers focus on the design, construction and maintenance of transport systems.
Most entry-level positions in the field will require a bachelor's degree in engineering, while advancement in the field may require a master's degree in the more specific discipline of transportation engineering.
Hope that helps!