Transportation or transport is the movement of people, goods, signals and information. The term is derived from the Latin trans ("across") and portare ("to carry").
Aspects of transportEdit
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, bicycles[], buses, trains, airplanes. The operations deal with the control of the system, such as traffic signals and ramp meters, railroad switches, air traffic control, etc. Another aspect is also on policies, such as how to finance the system (for example, the use of road tolls or gasoline taxes).
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 ngineering[].
Modes of transportEdit
Categories of transport Edit
- (Non-human) Animal-powered transport
- * * *Aviation[]
- Cable transport
- Conveyor transport
- Human-powered transport
- Hybrid transport
- Ship transport
- Space transport
- Transport on other planets
- Proposed future transport
Transport and communications Edit
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.
There is a well-known relationship between the density of development, and types of transportation. Intensity of development is often measured by area of Floor Area Ratio (FAR), the ratio of useable floorspace to area of land. As a rule of thumb, FARs of 1.5 or less are well suited to automobiles, those of six and above are well suited to trains. The range of densities from about two up to about four is not well served by conventional public or private transport. Many cities have grown into these densities, and are suffering traffic problems. Personal rapid transit could provide a solution to this problem.
Land uses support activities. Those activities are spatially separated. People need transport to go from one to the other (from home to work to shop back to home for instance). Transport is a "derived demand," in that transport is unnecessary but for the activities pursued at the ends of trips.
Good land use keeps common activities close (e.g. housing and food shopping), and places higher-density development closer to transportation lines and hubs. Poor land use concentrates activities (such as jobs) far from other destinations (such as housing and shopping).
There are economies of agglomeration. Beyond transportation some land uses are more efficient when clustered. Transportation facilities consume land, and in cities, pavement (devoted to streets and parking) can easily exceed 20 percent of the total land use. An efficient transport system can reduce land waste.
Transport, energy, and the environment Edit
Transport is a major use of energy, and transport burns most of the world's petroleum. Hydrocarbon fuels produce carbon dioxide, a greenhouse gas widely thought to be the chief cause of global climate change, and petroleum-powered engines, especially inefficient ones, create air pollution, including nitrous oxides and particulates (soot). Although vehicles in the United States have been getting cleaner because of environmental regulations, this has been offset by an increase in the number of vehicles and more use of each vehicle.
Other environmental impacts of transport systems include traffic congestion, toxic runoff from roads and parking lots that can pollute water supplies and aquatic ecosystems, and automobile-oriented urban sprawl, which can consume natural habitat and agricultural lands.
Low-pollution fuels can reduce pollution. Low pollution fuels may have a reduced carbon content, and thereby contribute less in the way of carbon dioxide emissions, and generally have reduced sulfur, since sulfur exhaust is a cause of acid rain. The most popular low-pollution fuel at this time is liquified natural gas. Hydrogen is an even lower-pollution fuel that produces no carbon dioxide, but producing and storing it economically is currently not feasible. Other alternative renewable energy sources such as biodiesel are being researched heavily.
Another strategy is to make vehicles more efficient, which reduces pollution and waste by reducing the energy use. Electric vehicles use efficient electric motors, but their range is limited by either the extent of the electric transmission system or by the storage capacity of batteries. Electrified public transport generally uses overhead wires or third rails to transmit electricity to vehicles, and is used for both rail and bus transport. Battery electric vehicles store their electric fuel onboard in a battery pack. Another method is to generate energy using fuel cells, which may eventually be two to five times as efficient as the internal combustion engines currently used in most vehicles. Another effective method is to streamline ground vehicles, which spend up to 75% of their energy on air-resistance, and to reduce their weight. Regenerative braking is possible in all electric vehicles and recaptures the energy normally lost to braking, and is becoming common in rail vehicles. In internal combustion automobiles and buses, regenerative braking is not possible, unless electric vehicle components are also a part of the powertrain, these are called hybrid electric vehicles.
Shifting travel from automobiles to well-utilized public transport can reduce energy consumption and traffic congestion.
Use of non-motorized modes walking and bicycling also reduces the consumption of fossil fuels. However, as most areas get wealthier, the use of these modes declines. There are a few wealthy cities where bicycling comprises a significant share of trips, including Copenhagen[], Denmark[] and Groningen [], Netherlands[]. A number of other cities, including London[], Paris[], New York[], Bogotá[], Chicago[], and San Francisco[], are creating networks of bicycle lanes and bicycle paths to encourage bicycling by increasing safety from traffic.
Transport Research Edit
Transport research facilities are mainly attached to universities or are steered by the state. In most countries (not in France and Spain) one can see now how laboratories are brought into PPP-operation, where industry takes over part of the share.
Some major players in Europe:
- Transport Research Laboratory TRL UK
- Joint OECD-ECMT Transport Research Centre
- European Conference of Ministers of Transport
- [] Institute of Transportation Studies, University of California, Berkeley
- National Transportation Research Center
- Transportation Research Board
See also Edit
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