Transport, or transportation (as it is called in the United States), is the movement of people and goods from one place to another. The term is derived from the Latin trans meaning across and portare meaning to carry.
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, train stations, bus stations and ports). 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 gas 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.
Modes are combinations of networks, vehicles, and operations, and include walking, the automobile/ highway system, railroads, maritime transport ( ships, waterways, and harbors), and modern air transport (airplanes, airports, and air traffic control).
Transport and communication are both substitutes and complements. Though it might be possible that sufficiently advanced communication could substitute for transport, one could telegraph, telephone, fax, or email a customer rather than visiting them in person, it has been found that those modes of communication in fact generate more total interactions, including interpersonal interactions. The growth in transport would be impossible without communication, which is vital for advanced transportation systems, from railroads which want to run trains in two directions on a single track, to air traffic control which requires knowing the location of aircraft in the sky. Thus, it has been found that the increase of one generally leads to more of the other.
Transport and land use are two sides of the same coin. Land uses (whether land is dedicated to houses, jobs, parks, etc.) generate activities that are pursued there. Those activities are spatially separated, and thus require transport to go from one to the other (from home to work to shop back to home for instance). Total time in a day can be divided between time spent at activities and time spent traveling to activities. It is often said that transport is a "derived demand", that there wouldn't be any transport but for the activities pursued at the ends of trips.
Good land use design, which bring a variety of activities within close proximity, can minimize, but not eliminate the need for transportation. Poor land use design, which concentrates certain activities at one place to the exclusion of other activities or land use types, does increase the need for transport. Still, there are economies of agglomeration, so land uses can't be completely heterogeneous, there is some advantage, beyond transportation, for some types of land uses to be clustered together. It is the degree of clustering, which trades of transport costs with other costs, that land use design is concerned with.
Transport and land use interact in another way, transportation facilities consume land, and in cities, pavement (devoted to streets and parking) is a good fraction of the total land use. An efficient transport system can avoid wasting land. However, this must be traded off with cost, as an efficient transport system for a large, high density city differs greatly than an efficient system for a small, low density city.
Transport is a major consumer of energy, which is usually burned in the vehicles themselves (though electric powered vehicles are "clean" at the vehicle, and generate the electricity elsewhere. The burning of energy can lead to waste by-products, which if not properly contained or transformed creates pollution. Though over the past 30 years, vehicles in the United States have been getting cleaner with environmental regulations[?], this has been partially offset by the total rise in both the number of vehicles and the increasing annual use of each vehicle.
The term penal transportation refers to sending persons abroad as punishment.