The field of transport has several aspects: loosely they can be divided into a triad of infrastructure, vehicles, and operations. Infrastructure includes the transport networks (roads, railways, airways, canals, pipelines, etc.) that are used, as well as the nodes or terminals (such as airports, railway stations, bus stations and seaports). The vehicles generally ride on the networks, such as automobiles, trains, airplanes. The operations deal with the control of the system, such as traffic signals and ramp meters, railroad switches, air traffic control, etc, as well as policies, such as how to finance the system (e.g. use of tolls or gasoline taxes in the case of highway transport).
Broadly speaking, the design of networks are the domain of civil engineering and urban planning, the design of vehicles of mechanical engineering and specialized subfields such as nautical engineering and aerospace engineering, and the operations are usually specialized, though might appropriately belong to operations research or systems engineering.