Units of measurement in transportation

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The units of measurement in transportation describes the unit of measurement used to express various transportation quantities, as used in statistics, planning, and their related applications.

Contents

Transportation quantity

The currently popular units are:

Length of journey

Traffic flow

Passenger

Payload quantity

Passenger-distance

Passenger-distance is the distance (km or miles) travelled by passengers on transit vehicles; determined by multiplying the number of unlinked passenger trips by the average length of their trips.

Passengers per hour per direction

Passengers per hour per direction (pphpd) measures the maximum route capacity of a transport system.

Passengers per bus hour

A system may carry a high number of passengers per distance (km or mile) but a relatively low number of passengers per bus hour if vehicles operate in congested areas and thus travel at slower speed.

Passengers per bus distance

A transit system serving a community with a widely dispersed population must operate circuitous routes that tend to carry fewer passengers per distance (km or mile). A higher number is more favorable.

Freight

Freight is measured in mass-distance. A simple unit of freight is the kilogram-kilometre (kgkm), the service of moving one kilogram of payload a distance of one kilometre.

Payload quantity

1 t = (1/0.907) short tons = 1.102 short tons.

Payload-distance

Usage

The metric units (pkm and tkm) are used internationally. (In aviation where United States customary units are widely used, the International Air Transport Association (IATA) releases its statistics in the metric units.)

In the US, sometimes United States customary units are used.

Derivation

The dimension of the measure is the product of the payload mass and the distance transported.

Example

A semi truck traveling from Los Angeles to Chicago (approximate distance 2,015 miles) carrying 14 short tons of cargo delivers a service of 14 * 2,015 = 28,210 ton-miles of freight (equal to about 41,187 tkm).

Intermodal containers

Intermodal container traffic is commonly measured in twenty-foot equivalent units (TEUs), rather than cargo weight, e.g. a TEU-km would be the equivalent of one twenty-foot container transported one kilometer. [6]

Transportation density

Transportation density can be defined as the payload per period, say passenger / day or tonne / day. This can be used as the measure of intensity of the transportation on a particular section or point of transportation infrastructure, say road or railway. This can be used in comparison with the construction, running costs of the infrastructure.

Fatalities by VMT

Fatalities by VMT (vehicle miles traveled) is a unit for assessing road traffic fatalities. This metric is computed by dividing the fatalities by the estimated VMT.

Usually, transport risk is computed by reference to the distance traveled by people, while for road traffic risk, only vehicle traveled distance is usually taken into account. [7]

In the United States, the unit is used as an aggregate in yearly federal publications, while its usage is more sporadic in other countries. For instance, it appears to compare different kind of roads in some publications as it had been computed on a five-year period between 1995 and 2000. [8]

In the United States, it is computed per 100 million miles traveled, while internationally it is computed in 100 million or 1 billion kilometers traveled.

According to the Minnesota Department of Public Safety, Office of Traffic Safety

Volume of traffic, or vehicle miles traveled (VMT), is a predictor of crash incidence. All other things being equal, as VMT increases, so will traffic crashes. The relationship may not be simple, however; after a point, increasing congestion leads to reduced speeds, hanging the proportion of crashes that occur at different severity levels. [9]

Energy efficiency

Energy efficiency in transport can be measured in L/100 km or miles per gallon (mpg). This can be normalized per vehicle, as in fuel economy in automobiles, or per seat, as for example in fuel economy in aircraft.

History

MacNeal 1994 [10] discusses the history of this topic, exploring such units and how humans developed the current state of logically recognizing and naming them.

See also

Related Research Articles

Transportation in Canada Overview of transportation in Canada

Canada, the world's second-largest country in total area, is dedicated to having an efficient, high-capacity multimodal transport spanning often vast distances between natural resource extraction sites, agricultural and urban areas. Canada's transportation system includes more than 1,400,000 kilometres (870,000 mi) of roads, 10 major international airports, 300 smaller airports, 72,093 km (44,797 mi) of functioning railway track, and more than 300 commercial ports and harbours that provide access to the Pacific, Atlantic and Arctic oceans as well as the Great Lakes and the St. Lawrence Seaway. In 2005, the transportation sector made up 4.2% of Canada's GDP, compared to 3.7% for Canada's mining and oil and gas extraction industries.

Transport in the Netherlands Overview of the transport in the Netherlands

The Netherlands is both a very densely populated and a highly developed country in which transport is a key factor of the economy. Correspondingly it has a very dense and modern infrastructure, facilitating transport with road, rail, air and water networks. In its Global Competitiveness Report for 2014-2015, the World Economic Forum ranked the Dutch transport infrastructure fourth in the world.

<span class="mw-page-title-main">Transport in China</span> Overview of the transport in China

Transport in China has experienced major growth and expansion in recent years. Although China's transport system comprises a vast network of transport nodes across its huge territory, the nodes tend to concentrate in the more economically developed coastal areas and inland cities along major rivers. The physical state and comprehensiveness of China's transport infrastructure tend to vary widely by geography. While remote, rural areas still largely depend on non-mechanized means of transport, a modern maglev system was built in China to connect the city center of Shanghai with Shanghai Pudong International Airport. Airports, roads, and railway construction will provide a massive employment boost in China over the next decade.

Rail transport Method of transportation

Rail transport is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are located on tracks. In contrast to road transport, where the vehicles run on a prepared flat surface, rail vehicles are directionally guided by the tracks on which they run. Tracks usually consist of steel rails, installed on sleepers (ties) set in ballast, on which the rolling stock, usually fitted with metal wheels, moves. Other variations are also possible, such as "slab track", in which the rails are fastened to a concrete foundation resting on a prepared subsurface.

Fuel efficiency Form of thermal efficiency

Fuel efficiency is a form of thermal efficiency, meaning the ratio of effort to result of a process that converts chemical potential energy contained in a carrier (fuel) into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is often illustrated as a continuous energy profile. Non-transportation applications, such as industry, benefit from increased fuel efficiency, especially fossil fuel power plants or industries dealing with combustion, such as ammonia production during the Haber process.

<span class="mw-page-title-main">Twenty-foot equivalent unit</span> Unit of cargo capacity

The twenty-foot equivalent unit is an inexact unit of cargo capacity, often used for container ships and container ports. It is based on the volume of a 20-foot-long (6.1 m) intermodal container, a standard-sized metal box which can be easily transferred between different modes of transportation, such as ships, trains, and trucks.

<span class="mw-page-title-main">Commercial driver's license</span> License to operate large or heavy vehicles

A commercial driver's license (CDL) is a driver's license required to operate large, heavy, or placarded hazardous material vehicles in commerce, including trucks, buses, and trailers.

<span class="mw-page-title-main">Rail freight transport</span> Train that carries cargo

Rail freight transport is the use of railroads and trains to transport cargo as opposed to human passengers.

Annual average daily traffic, abbreviated AADT, is a measure used primarily in transportation planning, transportation engineering and retail location selection. Traditionally, it is the total volume of vehicle traffic of a highway or road for a year divided by 365 days. AADT is a simple, but useful, measurement of how busy the road is.

<span class="mw-page-title-main">Passenger</span> Person who travels in a vehicle without operating it

A passenger is a person who travels in a vehicle, but does not bear any responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle, and is not a steward. The vehicles may be bicycles, buses, passenger trains, airliners, ships, ferryboats, and other methods of transportation.

<span class="mw-page-title-main">Transportation safety in the United States</span> Overview of transportation safety

Transportation safety in the United States encompasses safety of transportation in the United States, including automobile crashes, airplane crashes, rail crashes, and other mass transit incidents, although the most fatalities are generated by road incidents yearly killing from 32,479 to nearly 38,680 (+19%) in the last decade. The number of deaths per passenger-mile on commercial airlines in the United States between 2000 and 2010 was about 0.2 deaths per 10 billion passenger-miles. For driving, the rate was 150 per 10 billion vehicle-miles: 750 times higher per mile than for flying in a commercial airplane.

Energy efficiency in transport Discussing what form of transport is the most fuel efficient and economical.

The energy efficiency in transport is the useful travelled distance, of passengers, goods or any type of load; divided by the total energy put into the transport propulsion means. The energy input might be rendered in several different types depending on the type of propulsion, and normally such energy is presented in liquid fuels, electrical energy or food energy. The energy efficiency is also occasionally known as energy intensity. The inverse of the energy efficiency in transport, is the energy consumption in transport.

The Port of Constanța is located in Constanța, Romania, on the western coast of the Black Sea, 179 nautical miles (332 km) from the Bosphorus Strait and 85 nmi (157 km) from the Sulina Branch, through which the Danube river flows into the sea. It covers 3,926 ha, of which 1,313 ha is land and the rest, 2,613 ha is water. The two breakwaters located northwards and southwards shelter the port, creating the safest conditions for port activities. The present length of the north breakwater is 8,344 m (5.185 mi) and the south breakwater is 5,560 m (3.45 mi). The Port of Constanța is the largest on the Black Sea and the 17th largest in Europe.

Rail transport in the Soviet Union Overview of rail transport in the Soviet Union

The Soviet Union was heavily dependent on rail transport, not least during the Russian Civil War and World War II, but also for industrialization according to the five-year plans.

A vehicle miles traveled tax, also frequently referred to as a VMT tax, VMT fee, mileage-based fee, or road user charge, is a policy of charging motorists based on how many miles they have traveled.

Epidemiology of motor vehicle collisions Overview of the epidemiology of motor vehicle collisions

Worldwide it was estimated that 1.25 million people were killed and many millions more were injured in motor vehicle collisions in 2013. This makes motor vehicle collisions the leading cause of death among young adults of 15–29 years of age and the ninth cause of death for all ages worldwide. In the United States, 40,100 people died and 2.8 million were injured in crashes in 2017, and around 2,000 children under 16 years old die every year.

Public transport Shared transportation service for use by the general public

Public transport is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typically managed on a schedule, operated on established routes, and that charge a posted fee for each trip. There is no rigid definition; the Encyclopædia Britannica specifies that public transportation is within urban areas, and air travel is often not thought of when discussing public transport—dictionaries use wording like "buses, trains, etc." Examples of public transport include city buses, trolleybuses, trams and passenger trains, rapid transit and ferries. Public transport between cities is dominated by airlines, coaches, and intercity rail. High-speed rail networks are being developed in many parts of the world.

Peak car

Peak car is a hypothesis that motor vehicle distance traveled per capita, predominantly by private car, has peaked and will now fall in a sustained manner. The theory was developed as an alternative to the prevailing market saturation model, which suggested that car use would saturate and then remain reasonably constant, or to GDP-based theories which predict that traffic will increase again as the economy improves, linking recent traffic reductions to the Great Recession of 2008.

<span class="mw-page-title-main">Comparison of MUTCD-influenced traffic signs</span>

Road signs used by countries in the Americas are significantly influenced by the Manual on Uniform Traffic Control Devices (MUTCD), first released in 1935, reflecting the influence of the United States throughout the region. Other non-American countries using road signs similar to the MUTCD include Australia, Indonesia, Ireland, Japan, Malaysia, New Zealand, and Thailand. They, along with the US Virgin Islands, are also the only countries listed here which drive on the left—with the exception of Liberia and the Philippines, both of which drive on the right.

References

  1. 1 2 Dunkerley, Fay; Rohr, Charlene; Daly, Andrew (2014). Road traffic demand elasticities A rapid evidence assessment (PDF) (Report). Santa Monica, Calif.: RAND Corporation.
  2. "vehicle-km". Environmental Terminology Discovery Service. European Environment Agency. Retrieved 2008-10-06.
  3. Duden – Wörterbuch der Abkürzungen. Von Josef Werlin. 4., neu bearbeitete und erweiterte Auflage. Mannheim, Leipzig, Wien, Zürich: Dudenverlag 1999; http://www.duden.de/duden-suche/werke/abklex/000/012/kmt.12117.html
  4. Woxikon – http://abkuerzungen.woxikon.de/abkuerzung/kmt.php
  5. "Main Terms Used in Civil Aviation Statistics" (docx).
  6. Directorate, OECD Statistics. "OECD Glossary of Statistical Terms – TEU-kilometre Definition". stats.oecd.org.
  7. http://www.ladocumentationfrancaise.fr/var/storage/rapports-publics/134000525.pdf [ bare URL PDF ]
  8. http://dtrf.setra.fr/pdf/pj/Dtrf/0002/Dtrf-0002649/DT2649.pdf [ bare URL PDF ]
  9. https://dps.mn.gov/divisions/ots/reports-statistics/Documents/2014-crash-facts.pdf [ bare URL PDF ]
  10. MacNeal, Edward (1994). Mathsemantics: Making Numbers Talk Sense. Penguin. ISBN   9780140234862.{{cite book}}: CS1 maint: postscript (link)