El transporte puede ser clasificado de varias maneras de forma simultánea.

Passenger and cargo transportation

Freight transportation is the discipline that studies the best way to transport goods from one place to another. Associated with cargo transportation is Logistics, which consists of placing important products at the precise time and at the desired destination.[12]​[13]​

The biggest difference in passenger transportation is that travel time and comfort are counted.[14]​.

Urban and interurban transport

This classification is very important due to the differences that the two types of trips imply. While urban trips are short, very frequent and recurring, intercity trips are long, less frequent and recurring.

Public and private transportation

The classification between public transport and private transport does not indicate public or private ownership (public company or private company), but rather the possibility that the general public has of accessing passenger transport that is carried out collectively in a common vehicle (collective or public transport) or the possibility that each individual has of making the trip they want by themselves in their own vehicle (individual or private transport).

Public transport is defined as transport in which travelers share the means of transport and which is available to the general public. It includes various means such as buses, trolleybuses, trams, trains, suburban railways or ferries. Air transport and high-speed trains also coexist in interregional transport.

Public transportation differs from private transportation basically in that:

• - in private transport the user can select the route.

• - in private transport the user can select the departure time, while in public transport the user must stick to the schedules.

• - in private transport the user can infer the speed of the trip, while in public transport the travel time is given by the stops, schedules and speed of operation.

• - in public transport the user receives a service in exchange for a payment, technically known as a "Fare (public service)" fare, while in private transport, the user operates his vehicle and bears its costs.

The most representative of the private transportation modes is the automobile. However, walking and cycling are also within this classification. The taxi, despite being a service open to the public, is classified as private transport.

School transportation

School transportation or student transportation carries out trips for children and adolescents from their places of residence to schools and vice versa. Although many of these trips are carried out by private means of transport, it is also very common for them to be carried out collectively in special buses and caravans for this purpose.

In the United States and other countries, it is common for buses to take schoolchildren from their place of residence to school. The regulations in that country require that an adult caregiver, apart from the driver, ride the bus and that the buses are not older than 16 years. In the town of Davis, more than 40% of boys and girls ride bicycles to school.

In other countries such as Germany or Finland, students go alone in the city's public transport vehicles. Normally, students receive a card that allows them to use these services for the entire semester unlimitedly, at a very low (subsidized) cost.

Chile offers a deferred fare for students that can be opted for by presenting a school pass at the time of canceling the ticket. This in turn allows you to opt for different rates, with primary education being a free ticket and secondary education as well as higher education being a percentage of the adult ticket (50% in regions and 33% in Santiago).

The means or mobile elements (vehicles) and the infrastructure necessary to carry out movements in the different modes (land, sea, air or multimodal)[15]​ include (in addition to those necessary for the pedestrian to move on their own) the bicycle, the car, the bus, the truck, the railways, the river and maritime transport (ships, canals and ports), the air transport (airplanes, airports and air traffic control), including the union of several or the three types of transport.[16] We speak of modal distribution to describe, in a given area, how trips are distributed between the different modes that use the infrastructure (similar or different: railways and roads in the urban area).

According to the modes of transport used, transport is classified or categorized into:.

• - Road transport: pedestrians, bicycles, cars and other trackless vehicles.

• - Rail transport: rolling stock on railway tracks.

• - Transport by navigable waterways: maritime transport and river transport. For water, the boat is the best known.

• - Air transport: aircraft and airports.

• - Combined transport: several modes of transport are used and the merchandise is transferred from vehicle to another. This mode of transport has developed, giving rise to intermodal transport or multimodal transport, in which the merchandise is grouped into "superior load units", such as the container, which allow transport by different routes without "load breakage".

• - Vertical transport: elevators and freight elevators.

• - Pipeline transportation: oil and gas pipelines, in which fluids are propelled through pipes using pumping or compression stations.

The integration between more than two modes of transport is multimodal integration, said integration can be physical, operational or tariff. For example, integration between a bus and a metro or tram system.

The integration between routes of a single mode of transport, said integration can be physical, operational or fare. For example, integration between two routes where the passenger benefits with a lower fare for using them on a route.

Regarding its spatial or geographical configuration (transport geography), transport is specified in transport lines")[17]​ that are articulated through transport nodes")[18]​ in transport networks").[19]​ These can be:.

• - Centralized network") or radiocentric network"): all (or most, or the most important part) of the lines intersect at a central node, which may imply a privilege for that point to the detriment of the periphery (centralism), but also imply traffic congestion problems.

• - Reticular network"): several lines cross at different nodes, which, since there are several, do not present these problems, although others do.

• - Linear network"): a single line connects two end points (terminals).[20]​.

The density of a transport network is calculated by dividing its number of linear kilometers by the number of square kilometers of the surface it covers.

The concept of "transport route" applies to each of the established routes (with a certain stability of passage times) between different points of origin and destination (and, where appropriate, with stopovers or intermediate stops) in a regular transportation system, or to tourist routes.

As a historiographic concept, it is applied to the most important commercial routes that were established since Antiquity and the Middle Ages, such as those that described the Carthaginian and Greek journeys (between the Eastern and Western Mediterranean, and beyond the Strait of Gibraltar, through the Atlantic), the Silk Road on the Eurasian continent, the "gold route") of the trans-Saharan trade, the roads of Santiago, the Hansa route (which linked ports in Northern Europe, between the Baltic and the North Sea) and the fair route (which linked cities in Western Europe, between Spain, Italy and Flanders, centered on the Champagne fairs); while in the Modern Age the spice route stood out, which stimulated competition between the Portuguese, Spanish and Dutch empires, or the three triangular trade routes in the Atlantic Ocean (which included the slave route). With a strategic nature, the route of the thirds or Spanish road.

La modelización de transporte o modelación de transporte permite planificar situaciones futuras y actuales del transporte urbano. El concepto de “modelo” debe ser entendido como una representación, necesariamente simplificada, de cualquier fenómeno, proceso, institución y, en general, de cualquier “sistema”. Es una herramienta de gran importancia para el planificador, pues permite simular escenarios de actuación y temporales diversos que ayudan a evaluar alternativas y realizar el diagnóstico de futuro.

El esquema clásico de modelación es el de cuatro etapas o cuatro pasos.

• - Paso 1: Modelos de generación de viajes para evaluar viajes producidos y atraídos por cada zona de transporte en distintos escenarios.

• - Paso 2: Modelos de distribución, para estimar matrices origen-destino (O/D) futuras.

• - Paso 3: Modelos de selección modal, para determinar la captación de cada modo entre las distintas relaciones O/D, para los motivos que se calibren.

• - Paso 4: Modelos de selección de ruta o asignación que permite determinar los caminos o rutas escogidas para cada relación y la carga por tramos para líneas o redes viarias en los distintos períodos horarios analizados.

A veces, según los datos disponibles y el tipo de análisis que se desea se puede prescindir del modelo de generación, quedando en tres etapas y obteniéndose únicamente el modelo de distribución. En corredores de carreteras sin transporte público realmente competitivo, es frecuente suponer que no hay trasvase modal y solo se use el de distribución (o un modelo de crecimientos) y el de asignación únicamente.

También se pueden mencionar otros tipos de modelos como los de usos del suelo que permiten análisis interrelacionados y complejos entre actividad en el territorio y transportes.

Transport network design

Networks are designed considering three aspects: geometry, resistance and capacity. In practice, transportation design focuses on taking geometric designs and defining their width, number of lanes, roads or diameter. Your product is taken by the pavement, rail, bridge or pipeline specialist and converted into thicknesses of roadway, ballast, beams or pipe walls. The transportation engineer is also responsible for defining the operation of the system considering time.

The main methods for network design include the four-stage method, the use of queuing theory, simulation, and what could be called empirical coefficient methods.

In this transportation modeling method, "trip generation," or the number of people or amount of freight that an area produces, is calculated separately; the "trip distribution" of trips, which allows estimating the number of trips or amount of cargo between each origin and destination area; the "modal split", that is, the calculation of the number of trips or amount of cargo that the different modes of transport will use and their conversion into the number of vehicles; and, finally, the "assignment", or the definition of which network segments or routes each of the vehicles will use.

This process is carried out using the density and location of the population or current load to verify that the volumes predicted by the method agree with reality. Finally, future population estimates are used to recalculate the number of vehicles in each arc of the network that will be used for the design. It is primarily used to design transportation and is required by law in many urban areas.

Use statistics and certain assumptions about the service process. It allows estimating, based on the arrival rates of customers (whether vehicles or people) and the speed of service of each service channel, the queue length and the average service time. The customer arrival rate must be analyzed to know not only its intensity in number of customers per hour, but also its distribution over time. It has been found, experimentally, that the Poisson distribution and the geometric distributions reflect well the random arrival of customers and the arrival of clustered customers, respectively. It is mainly used to estimate the number of toll booths, pumps at fuel stations, service stations at ports and airports, and the number of ATMs or customer service lines required in an establishment. Queuing theory is based on stochastic processes...

There are two main types of computer simulations used in transportation engineering: macrosimulations and microsimulations.

Macrosimulations use equations that reflect general parameters of the vehicle flow, such as speed, density and flow. Many of the ideas behind these equations are taken from the analysis of the flow of liquids or gases or from empirically found relationships between these quantities and their derivatives.

The latter simulate each vehicle or person individually and make use of equations that describe the behavior of these vehicles or people when they follow another (vehicle following equations) or when they circulate without impediments.

They use theoretical equations but, in general, they are based on measurements that indicate the capacity of a network under ideal conditions. This capacity normally decreases as the network or circumstances move away from that ideal.

The methods provide coefficients less than unity, by which the "ideal" capacity of the network must be multiplied to find the capacity under the given conditions. and that more things.

Transportation and communication are both substitutes and complements. Although the advancement of communications is important and allows information to be transmitted by telegraph, telephone, fax or email, personal contact has its own characteristics that cannot be replaced.

Transportation growth would be impossible without communication, vital for advanced transportation systems (train control, air traffic control, road traffic status monitoring, etc.). There is, however, no proven relationship between the growth of these two systems. The best predictor of the growth of a transportation system is the growth of an area's gross domestic product (GDP). It is also relatively easy to find GDP predictions. The use of historical series to predict the future growth of the transportation system can lead to serious errors (problem of "sub-optimization" or fragmentary analysis of a system).[21]​.

The theory of mobility") in transportation is a social theory initiated in Lancaster, United Kingdom by the sociologist John Urry.[22]​ Its academic position suggests that the globalized world is characterized by high mobility that connects people, goods, signs and geographical spaces through transportation.[23]​ Geographic spaces are integrated through signs that are their own and that can be exchanged semiotically.[24]​ These signs not only confer value to the consumed product but are They connect to a cultural matrix that offers the tourist a diversity of landscapes.[25]​ The theory of mobility suggests that there are different ways of moving that condition the subject and their conception of the environment.[26]​ Urry maintains that modern tourists and travelers move outside their homes with the ultimate goal of possessing what they want to see. "Other".[27]​.

In recent years, some authors such as Maximiliano Korstanje and Rodanthi Tzanelli have established a critical approach to mobility theory, arguing that beyond the paradigm, real mobility in the global north differs substantially from the south.[28]​ In this sense, mobility theory finds certain limitations to explain the reality of underdeveloped countries in the global south, where mobility is not the rule but the exception.[29]​ In this sense, Raoul Bianchi offers an explanation. about the different asymmetries and class inequalities that globalization opens up on the planet.[30]​.

For his part, Philip Vannini maintains that the sociology of mobility must pay particular attention to the means of transportation as well as their sociocultural impacts on daily life and culture itself. Global capitalism creates specific discursivities that legitimize the exclusion of certain actors from the productive system. To this end, mobility must be understood as a sign of status for those groups that are entitled to travel, while others are immobilized without any possibility of doing so.[31]​.

Transportation and land use are directly related. Depending on the use of the land, specific activities are generated that do not necessarily coincide with the place of residence of those who carry them out, in which case they must be moved. A day can be divided between the time spent on activities and the time spent traveling to and from the place where those activities take place. It is said that transportation is "an indirect demand", since it has no end in itself, but is necessary to develop activities at the destination.

Clustering a variety of activities within the same land area minimizes the need for transportation. On the contrary, the organization by zones of exclusive activities increases it. However, there are economies of scale when grouping activities, which prevents the organization of activities by completely heterogeneous areas.[32]​.

Transport and land use also interact in another way, since transport services consume land, as do cities. An efficient transportation system can minimize land use. However, this savings must be compared to the cost; An efficient transportation system in a large city can have an extremely high cost.[33]​.

Transportation is an important consumer of energy, it can be obtained by burning fuels, until not long ago mostly fossil fuels in combustion engines. In the combustion process, polluting gaseous emissions (CO, CO, NO, SO and others, such as particles) are generated, the harmfulness of which depends on the energy source used.

Electrically powered vehicles are often held to be "clean", as are those that use hydrogen cells. But in reality, it depends on the source the electricity comes from. If they use electricity produced in plants powered by fossil fuels, the pollution is more localized than with combustion cars, since carbon capture and storage techniques can be applied. If renewable sources (renewable electricity) are used, this emissions problem does not exist.

Given that the depletion of fossil fuels is expected around 2050, global transportation faces the challenge of completely modifying its systems in just under five decades. It is expected that hydrogen vehicles will be the most economical, if current technologies are extrapolated, so we will have to learn to produce it by methods other than the highly polluting one used today (treatment of natural gas with steam), which generates immense amounts of carbon dioxide, if we want its use to not contribute even more to global warming.

In recent years, vehicles have been becoming cleaner, as a result of stricter environmental regulations and the incorporation of better technologies (catalytic converters, etc.), and, above all, better use of fuel. However, this situation has been more than compensated by the rise in both the number of vehicles and the increasing annual use of each vehicle, which determines that cities with more than 1,000,000 inhabitants present problems of excessive air pollution rates, affecting the health of the population.

In 2009, NASA promoted the so-called Green Flight Challenge, a contest that awarded half a million dollars to the most original and efficient project. More than half a dozen projects have been submitted so far. The initiative is developed in cooperation with the following North American institutions: Department of Agriculture and Energy, the Environmental Protection Agency, the National Science Foundation and the National Institute of Trade in Standards and Technology, together with the Patent and Trademark Office. Some of these projects are:

Cri-Cri

A French-made and completely electric acrobatic airplane. It runs on four engines and has a flight range of 30 minutes at a cruising speed of 100 km/h.

SugarVolt

Hybrid model designed by Boeing. It works with a combination of kerosene (propeller) turbines, which are what make it take off. But, once in the air, needing less energy, it flies with an electric motor.

Skyhawk 172

The aeronautical firm Cessna plans to have it ready by the end of 2011. The small plane will only have two seats, but it is still estimated to be one of the most used due to its similarity to a previous model, to which improvements have been included.

The Super Boeing

Not all green planes will be electric. This is a Boeing supersonic prototype that runs on high-performance fuel, and is being designed in collaboration with NASA. Furthermore, regarding the aerial medium, there is another handicap to take into account. Currently, the innovations that have been made in airplanes limit commercial flights too much. That is to say, the market is close. The vast majority are private jets with few seats that do not allow mass transportation of passengers, therefore, the initial problem of making a low-polluting option feasible for the general public; In this case it is impossible at the moment.

The transportation and distribution of energy by means of transportation has caused multiple accidents that have seriously affected people, facilities and the environment. The transportation of energy varies depending on the type of energy to be transported.

• - Coal transportation: it is carried out mainly by road and rail, and lately river transportation is increasing.

• - Oil transportation: it is carried out mainly by oil pipelines and tankers, and to the consumer by tanker trucks.

• - The transport of electrical energy: it is carried out through electrical networks, which distribute the current from the primary transformer stations to the consumer and, sometimes, inversely (V2G).

The environment also causes important impacts on the energy system; It is worth highlighting the effect of earthquakes, hurricanes, storms, sudden variations in temperature, etc.

• - Portal:Transportes. Contenido relacionado con Transportes.

In relation to environmental impacts

• - Rural road.

• - Environmental impact of land roads.

In relation to animal locomotion

• - Animal locomotion.

• - Locomotor system.

• - Anatomy and physiology of mammals: locomotor system.

• - Anatomical location terms.

• - Speed ​​of animals.

• - Wikinews has news related to Transport.

• - Wiktionary has definitions and other information about transport.

• - International Treaties on Transport and Communications.

• - Means of Transport Exhibition, National Museum of Science and Technology of Spain.

• - The IPTS Report: The importance of transport for the manufacturing sector: its role in the sustainability agenda. Archived June 15, 2008 at the Wayback Machine. Institute for Technological Prospective (IPTS), Joint Research Center of the European Commission.

• - Transport and its infrastructure, IPCC 4 assessment-report.

El transporte puede ser clasificado de varias maneras de forma simultánea.

Passenger and cargo transportation

Freight transportation is the discipline that studies the best way to transport goods from one place to another. Associated with cargo transportation is Logistics, which consists of placing important products at the precise time and at the desired destination.[12]​[13]​

The biggest difference in passenger transportation is that travel time and comfort are counted.[14]​.

Urban and interurban transport

This classification is very important due to the differences that the two types of trips imply. While urban trips are short, very frequent and recurring, intercity trips are long, less frequent and recurring.

Public and private transportation

The classification between public transport and private transport does not indicate public or private ownership (public company or private company), but rather the possibility that the general public has of accessing passenger transport that is carried out collectively in a common vehicle (collective or public transport) or the possibility that each individual has of making the trip they want by themselves in their own vehicle (individual or private transport).

Public transport is defined as transport in which travelers share the means of transport and which is available to the general public. It includes various means such as buses, trolleybuses, trams, trains, suburban railways or ferries. Air transport and high-speed trains also coexist in interregional transport.

Public transportation differs from private transportation basically in that:

• - in private transport the user can select the route.

• - in private transport the user can select the departure time, while in public transport the user must stick to the schedules.

• - in private transport the user can infer the speed of the trip, while in public transport the travel time is given by the stops, schedules and speed of operation.

• - in public transport the user receives a service in exchange for a payment, technically known as a "Fare (public service)" fare, while in private transport, the user operates his vehicle and bears its costs.

The most representative of the private transportation modes is the automobile. However, walking and cycling are also within this classification. The taxi, despite being a service open to the public, is classified as private transport.

School transportation

School transportation or student transportation carries out trips for children and adolescents from their places of residence to schools and vice versa. Although many of these trips are carried out by private means of transport, it is also very common for them to be carried out collectively in special buses and caravans for this purpose.

In the United States and other countries, it is common for buses to take schoolchildren from their place of residence to school. The regulations in that country require that an adult caregiver, apart from the driver, ride the bus and that the buses are not older than 16 years. In the town of Davis, more than 40% of boys and girls ride bicycles to school.

In other countries such as Germany or Finland, students go alone in the city's public transport vehicles. Normally, students receive a card that allows them to use these services for the entire semester unlimitedly, at a very low (subsidized) cost.

Chile offers a deferred fare for students that can be opted for by presenting a school pass at the time of canceling the ticket. This in turn allows you to opt for different rates, with primary education being a free ticket and secondary education as well as higher education being a percentage of the adult ticket (50% in regions and 33% in Santiago).

The means or mobile elements (vehicles) and the infrastructure necessary to carry out movements in the different modes (land, sea, air or multimodal)[15]​ include (in addition to those necessary for the pedestrian to move on their own) the bicycle, the car, the bus, the truck, the railways, the river and maritime transport (ships, canals and ports), the air transport (airplanes, airports and air traffic control), including the union of several or the three types of transport.[16] We speak of modal distribution to describe, in a given area, how trips are distributed between the different modes that use the infrastructure (similar or different: railways and roads in the urban area).

According to the modes of transport used, transport is classified or categorized into:.

• - Road transport: pedestrians, bicycles, cars and other trackless vehicles.

• - Rail transport: rolling stock on railway tracks.

• - Transport by navigable waterways: maritime transport and river transport. For water, the boat is the best known.

• - Air transport: aircraft and airports.

• - Combined transport: several modes of transport are used and the merchandise is transferred from vehicle to another. This mode of transport has developed, giving rise to intermodal transport or multimodal transport, in which the merchandise is grouped into "superior load units", such as the container, which allow transport by different routes without "load breakage".

• - Vertical transport: elevators and freight elevators.

• - Pipeline transportation: oil and gas pipelines, in which fluids are propelled through pipes using pumping or compression stations.

The integration between more than two modes of transport is multimodal integration, said integration can be physical, operational or tariff. For example, integration between a bus and a metro or tram system.

The integration between routes of a single mode of transport, said integration can be physical, operational or fare. For example, integration between two routes where the passenger benefits with a lower fare for using them on a route.

Regarding its spatial or geographical configuration (transport geography), transport is specified in transport lines")[17]​ that are articulated through transport nodes")[18]​ in transport networks").[19]​ These can be:.

• - Centralized network") or radiocentric network"): all (or most, or the most important part) of the lines intersect at a central node, which may imply a privilege for that point to the detriment of the periphery (centralism), but also imply traffic congestion problems.

• - Reticular network"): several lines cross at different nodes, which, since there are several, do not present these problems, although others do.

• - Linear network"): a single line connects two end points (terminals).[20]​.

The density of a transport network is calculated by dividing its number of linear kilometers by the number of square kilometers of the surface it covers.

The concept of "transport route" applies to each of the established routes (with a certain stability of passage times) between different points of origin and destination (and, where appropriate, with stopovers or intermediate stops) in a regular transportation system, or to tourist routes.

As a historiographic concept, it is applied to the most important commercial routes that were established since Antiquity and the Middle Ages, such as those that described the Carthaginian and Greek journeys (between the Eastern and Western Mediterranean, and beyond the Strait of Gibraltar, through the Atlantic), the Silk Road on the Eurasian continent, the "gold route") of the trans-Saharan trade, the roads of Santiago, the Hansa route (which linked ports in Northern Europe, between the Baltic and the North Sea) and the fair route (which linked cities in Western Europe, between Spain, Italy and Flanders, centered on the Champagne fairs); while in the Modern Age the spice route stood out, which stimulated competition between the Portuguese, Spanish and Dutch empires, or the three triangular trade routes in the Atlantic Ocean (which included the slave route). With a strategic nature, the route of the thirds or Spanish road.

La modelización de transporte o modelación de transporte permite planificar situaciones futuras y actuales del transporte urbano. El concepto de “modelo” debe ser entendido como una representación, necesariamente simplificada, de cualquier fenómeno, proceso, institución y, en general, de cualquier “sistema”. Es una herramienta de gran importancia para el planificador, pues permite simular escenarios de actuación y temporales diversos que ayudan a evaluar alternativas y realizar el diagnóstico de futuro.

El esquema clásico de modelación es el de cuatro etapas o cuatro pasos.

• - Paso 1: Modelos de generación de viajes para evaluar viajes producidos y atraídos por cada zona de transporte en distintos escenarios.

• - Paso 2: Modelos de distribución, para estimar matrices origen-destino (O/D) futuras.

• - Paso 3: Modelos de selección modal, para determinar la captación de cada modo entre las distintas relaciones O/D, para los motivos que se calibren.

• - Paso 4: Modelos de selección de ruta o asignación que permite determinar los caminos o rutas escogidas para cada relación y la carga por tramos para líneas o redes viarias en los distintos períodos horarios analizados.

A veces, según los datos disponibles y el tipo de análisis que se desea se puede prescindir del modelo de generación, quedando en tres etapas y obteniéndose únicamente el modelo de distribución. En corredores de carreteras sin transporte público realmente competitivo, es frecuente suponer que no hay trasvase modal y solo se use el de distribución (o un modelo de crecimientos) y el de asignación únicamente.

También se pueden mencionar otros tipos de modelos como los de usos del suelo que permiten análisis interrelacionados y complejos entre actividad en el territorio y transportes.

Transport network design

Networks are designed considering three aspects: geometry, resistance and capacity. In practice, transportation design focuses on taking geometric designs and defining their width, number of lanes, roads or diameter. Your product is taken by the pavement, rail, bridge or pipeline specialist and converted into thicknesses of roadway, ballast, beams or pipe walls. The transportation engineer is also responsible for defining the operation of the system considering time.

The main methods for network design include the four-stage method, the use of queuing theory, simulation, and what could be called empirical coefficient methods.

In this transportation modeling method, "trip generation," or the number of people or amount of freight that an area produces, is calculated separately; the "trip distribution" of trips, which allows estimating the number of trips or amount of cargo between each origin and destination area; the "modal split", that is, the calculation of the number of trips or amount of cargo that the different modes of transport will use and their conversion into the number of vehicles; and, finally, the "assignment", or the definition of which network segments or routes each of the vehicles will use.

This process is carried out using the density and location of the population or current load to verify that the volumes predicted by the method agree with reality. Finally, future population estimates are used to recalculate the number of vehicles in each arc of the network that will be used for the design. It is primarily used to design transportation and is required by law in many urban areas.

Use statistics and certain assumptions about the service process. It allows estimating, based on the arrival rates of customers (whether vehicles or people) and the speed of service of each service channel, the queue length and the average service time. The customer arrival rate must be analyzed to know not only its intensity in number of customers per hour, but also its distribution over time. It has been found, experimentally, that the Poisson distribution and the geometric distributions reflect well the random arrival of customers and the arrival of clustered customers, respectively. It is mainly used to estimate the number of toll booths, pumps at fuel stations, service stations at ports and airports, and the number of ATMs or customer service lines required in an establishment. Queuing theory is based on stochastic processes...

There are two main types of computer simulations used in transportation engineering: macrosimulations and microsimulations.

Macrosimulations use equations that reflect general parameters of the vehicle flow, such as speed, density and flow. Many of the ideas behind these equations are taken from the analysis of the flow of liquids or gases or from empirically found relationships between these quantities and their derivatives.

The latter simulate each vehicle or person individually and make use of equations that describe the behavior of these vehicles or people when they follow another (vehicle following equations) or when they circulate without impediments.

They use theoretical equations but, in general, they are based on measurements that indicate the capacity of a network under ideal conditions. This capacity normally decreases as the network or circumstances move away from that ideal.

The methods provide coefficients less than unity, by which the "ideal" capacity of the network must be multiplied to find the capacity under the given conditions. and that more things.

Transportation and communication are both substitutes and complements. Although the advancement of communications is important and allows information to be transmitted by telegraph, telephone, fax or email, personal contact has its own characteristics that cannot be replaced.

Transportation growth would be impossible without communication, vital for advanced transportation systems (train control, air traffic control, road traffic status monitoring, etc.). There is, however, no proven relationship between the growth of these two systems. The best predictor of the growth of a transportation system is the growth of an area's gross domestic product (GDP). It is also relatively easy to find GDP predictions. The use of historical series to predict the future growth of the transportation system can lead to serious errors (problem of "sub-optimization" or fragmentary analysis of a system).[21]​.

The theory of mobility") in transportation is a social theory initiated in Lancaster, United Kingdom by the sociologist John Urry.[22]​ Its academic position suggests that the globalized world is characterized by high mobility that connects people, goods, signs and geographical spaces through transportation.[23]​ Geographic spaces are integrated through signs that are their own and that can be exchanged semiotically.[24]​ These signs not only confer value to the consumed product but are They connect to a cultural matrix that offers the tourist a diversity of landscapes.[25]​ The theory of mobility suggests that there are different ways of moving that condition the subject and their conception of the environment.[26]​ Urry maintains that modern tourists and travelers move outside their homes with the ultimate goal of possessing what they want to see. "Other".[27]​.

In recent years, some authors such as Maximiliano Korstanje and Rodanthi Tzanelli have established a critical approach to mobility theory, arguing that beyond the paradigm, real mobility in the global north differs substantially from the south.[28]​ In this sense, mobility theory finds certain limitations to explain the reality of underdeveloped countries in the global south, where mobility is not the rule but the exception.[29]​ In this sense, Raoul Bianchi offers an explanation. about the different asymmetries and class inequalities that globalization opens up on the planet.[30]​.

For his part, Philip Vannini maintains that the sociology of mobility must pay particular attention to the means of transportation as well as their sociocultural impacts on daily life and culture itself. Global capitalism creates specific discursivities that legitimize the exclusion of certain actors from the productive system. To this end, mobility must be understood as a sign of status for those groups that are entitled to travel, while others are immobilized without any possibility of doing so.[31]​.

Transportation and land use are directly related. Depending on the use of the land, specific activities are generated that do not necessarily coincide with the place of residence of those who carry them out, in which case they must be moved. A day can be divided between the time spent on activities and the time spent traveling to and from the place where those activities take place. It is said that transportation is "an indirect demand", since it has no end in itself, but is necessary to develop activities at the destination.

Clustering a variety of activities within the same land area minimizes the need for transportation. On the contrary, the organization by zones of exclusive activities increases it. However, there are economies of scale when grouping activities, which prevents the organization of activities by completely heterogeneous areas.[32]​.

Transport and land use also interact in another way, since transport services consume land, as do cities. An efficient transportation system can minimize land use. However, this savings must be compared to the cost; An efficient transportation system in a large city can have an extremely high cost.[33]​.

Transportation is an important consumer of energy, it can be obtained by burning fuels, until not long ago mostly fossil fuels in combustion engines. In the combustion process, polluting gaseous emissions (CO, CO, NO, SO and others, such as particles) are generated, the harmfulness of which depends on the energy source used.

Electrically powered vehicles are often held to be "clean", as are those that use hydrogen cells. But in reality, it depends on the source the electricity comes from. If they use electricity produced in plants powered by fossil fuels, the pollution is more localized than with combustion cars, since carbon capture and storage techniques can be applied. If renewable sources (renewable electricity) are used, this emissions problem does not exist.

Given that the depletion of fossil fuels is expected around 2050, global transportation faces the challenge of completely modifying its systems in just under five decades. It is expected that hydrogen vehicles will be the most economical, if current technologies are extrapolated, so we will have to learn to produce it by methods other than the highly polluting one used today (treatment of natural gas with steam), which generates immense amounts of carbon dioxide, if we want its use to not contribute even more to global warming.

In recent years, vehicles have been becoming cleaner, as a result of stricter environmental regulations and the incorporation of better technologies (catalytic converters, etc.), and, above all, better use of fuel. However, this situation has been more than compensated by the rise in both the number of vehicles and the increasing annual use of each vehicle, which determines that cities with more than 1,000,000 inhabitants present problems of excessive air pollution rates, affecting the health of the population.

In 2009, NASA promoted the so-called Green Flight Challenge, a contest that awarded half a million dollars to the most original and efficient project. More than half a dozen projects have been submitted so far. The initiative is developed in cooperation with the following North American institutions: Department of Agriculture and Energy, the Environmental Protection Agency, the National Science Foundation and the National Institute of Trade in Standards and Technology, together with the Patent and Trademark Office. Some of these projects are:

Cri-Cri

A French-made and completely electric acrobatic airplane. It runs on four engines and has a flight range of 30 minutes at a cruising speed of 100 km/h.

SugarVolt

Hybrid model designed by Boeing. It works with a combination of kerosene (propeller) turbines, which are what make it take off. But, once in the air, needing less energy, it flies with an electric motor.

Skyhawk 172

The aeronautical firm Cessna plans to have it ready by the end of 2011. The small plane will only have two seats, but it is still estimated to be one of the most used due to its similarity to a previous model, to which improvements have been included.

The Super Boeing

Not all green planes will be electric. This is a Boeing supersonic prototype that runs on high-performance fuel, and is being designed in collaboration with NASA. Furthermore, regarding the aerial medium, there is another handicap to take into account. Currently, the innovations that have been made in airplanes limit commercial flights too much. That is to say, the market is close. The vast majority are private jets with few seats that do not allow mass transportation of passengers, therefore, the initial problem of making a low-polluting option feasible for the general public; In this case it is impossible at the moment.

The transportation and distribution of energy by means of transportation has caused multiple accidents that have seriously affected people, facilities and the environment. The transportation of energy varies depending on the type of energy to be transported.

• - Coal transportation: it is carried out mainly by road and rail, and lately river transportation is increasing.

• - Oil transportation: it is carried out mainly by oil pipelines and tankers, and to the consumer by tanker trucks.

• - The transport of electrical energy: it is carried out through electrical networks, which distribute the current from the primary transformer stations to the consumer and, sometimes, inversely (V2G).

The environment also causes important impacts on the energy system; It is worth highlighting the effect of earthquakes, hurricanes, storms, sudden variations in temperature, etc.

• - Portal:Transportes. Contenido relacionado con Transportes.

In relation to environmental impacts

• - Rural road.

• - Environmental impact of land roads.

In relation to animal locomotion

• - Animal locomotion.

• - Locomotor system.

• - Anatomy and physiology of mammals: locomotor system.

• - Anatomical location terms.

• - Speed ​​of animals.

• - Wikinews has news related to Transport.

• - Wiktionary has definitions and other information about transport.

• - International Treaties on Transport and Communications.

• - Means of Transport Exhibition, National Museum of Science and Technology of Spain.

• - The IPTS Report: The importance of transport for the manufacturing sector: its role in the sustainability agenda. Archived June 15, 2008 at the Wayback Machine. Institute for Technological Prospective (IPTS), Joint Research Center of the European Commission.

• - Transport and its infrastructure, IPCC 4 assessment-report.