As stated above, the aim of this paper is to study how transportation networks evolve under different decision-making processes and starting from different geographies and types of connection network. We discuss below how we deal with each one of these aspects. For the convenience of the reader, we include in Fig. 1 a flow chart of our model so the integration of each of the aspects discussed below can be easily assessed.
The first ingredient of our approach is a given geography of the region or country under consideration, understood as the positions of the population centers (towns, cities, villages) the network connects. To be sure, there is an infinite number of geographies one can consider, each with its own specific features and particular problems. However, in the spirit of addressing general problems, we focus on the differences between countries where the population concentrates in the periphery as compared with those in which the population is more uniformly distributed through the territory. Very roughly speaking, the former case would resemble a country like Spain or the United States, whereas the latter one would be similar to Germany, for instance. In addition, we will consider the effect of having a central hub and also the effect of having more or less towns. To this end we will use the following basic systems: a set of towns located on a circle, on two circles, with or without a town in a geographically centered position, or else a set of towns randomly scattered in the region under consideration. Examples of these basic configurations are shown on Fig. 2.
As we have already stated, the purpose of our research is to understand how to improve an already existing transportation network. In this respect, it is important to note that this is a very general approach to the problem. Communication or transportation networks exist since many centuries ago. In ancient times, when the first societies started to appear, there were paths between neighboring villages, possibly used only by people on foot or on horseback, but they were bona fide paths. Later road or railway networks, from the Roman empire road network to the current highways, can then be considered as improvements on that first set of paths (notice that the new connection needs not lay exactly on top of the previous one, it should just link the same two cities). Therefore, we will look at how transportation networks change, in the understanding that this allows us to understand the status of the network at very many different moments in history just by changing the choice of pre-existing network.
With the goal stated in the previous paragraph in mind, once we adopt a specific geography from those presented in the previous subsection, we need to specify the current state of the connections among towns. In choosing models for those, we restricted ourselves to two connected networks: the complete network, i.e., there is a direct connection bewteen any two nodes (which may be more realistically associated to large towns connected by direct flights, but could in principle correspond to any mode of transport), and a Delaunay network. A Delaunay triangulation14 for a set of points in a plane is a connected network such that no point in the set is inside the circumcircle of any triangle in the network. In this way, the resulting network maximizes the minimum angle of all the angles of the network triangles, leading to less obtuse forms. It is interesting to note that the dual graph15 of the Delaunay triangulation is a Voronoi graph16. Delaunay networks are appropriate for the purposes of modeling a pre-existing transportation network, which in this case could be thought of as formed by roads or railroads, because another of its properties is that it contains the nearest neighbor graph as a subgraph, meaning that there are direct links from any town to its closest neighboring one. Furthermore, it can be seen17 that the maximum distance between two nodes following paths on a Delaunay network is at most twice the distance as the bird flies, while in actual geographical terms is much smaller, between 1.05 and 1.0918. To implement the Delaunay network, we used the built-in Matlab19 command delaunay. In the next section, we will see that, in fact, Delaunay networks are indeed a good representation of efficient transportation networks.
An additional comments is in order here regarding our choice of pre-existing networks. First, it could be argued that another suitable starting point would be a minimum spanning tree (MST)20. However, MSTs are not very good models for transportation networks because they lack redundancy by definition (trees have no cycles) and are highly inefficient in terms of total transportation costs. Although MST are extremely efficient in terms of construction costs, they are much less efficient in terms of transportation time, as it may well be the case that two nodes that are very close geographically end up having to travel a very long path to reach each other. A limited increase in redundancy, along with a few extra links, may lead to a substantial decrease in transportation time and to an increase in the network resilience against problems in any of its links, while very moderately increasing the constructions costs. On the other hand, MSTs are very sensitive to geographical changes: adding one node to the system or displacing one may lead to drastic changes in the new MST. Therefore, we do not consider this option here for its lack of applicability.
In this work, we focus on the case in which decisions are taken by an external agent (government department, transport authority, etc) who tries to improve a pre-existing network by considering and balancing the interests of the different actors, in our case, the towns to be connected. It is important to understand this point because, as we will now define, decisions will be taken by an apparently “democratic” procedure, but this is not actual voting but rather the manner in which the external decision-maker weighs in the different characteristics of the town and the gains in network efficiency. Therefore, the alternative to our model would not be an external decision-making, but an external decision-making that uses other criteria for her choices (such as promoting a specific town, or a specific region).
In the above spirit, we complete our approach to the evolution of the transportation network by considering the case in which at every time step a particular link of the network is chosen and an investment is allocated to its improvement, leading to a reduction of the time needed to travel it by a factor of 75%. For the decision-making processes, i.e., for the procedure to choose links, we will restrict ourselves to bottom-up approaches (which, however, could also be seen as top-down if the decision-makers considered criteria based on the population distribution to choose the parts of the network to be improved) and, specifically, to the following ones, that touch upon different aspects of the weighting of towns and their main goal:
Decision-making process Type I: Each town has one vote on the link to be improved. The aim of this rule is to reduce the total cost of travels. Connections have a weight proportional to travel time.
Decision-making process Type II: Each town has one vote, weighted by its population, on the link to be improved. The aim here is to reduce the total cost in terms of the mean time spent by the population in traveling. Connections have a weight proportional to travel time.
Decision-making process Type III: Each town has one vote, weighted by its population. The goal is different in this case, the rule attempts to increase total traffic. Traffic is determined by a gravitational model21 that is proportionally to the size of the connected nodes and inversely proportional to the square of the distance between them (measured in time). When travel time is decreased by the connection improvement, the traffic is increased. This procedure puts more weight on connections with relevant nodes, be it by proximity or by population.
In our model, the vote of each town is decided based on its own optimal choices, as determined by the minimal spanning tree originating from them. The minimal spanning tree for the towns is determined by using the Dijkstra algorithm22, 23.
5 Modes Of Transportation
- Length: 1431 words (4.1 double-spaced pages)
- Rating: Excellent
5 Modes of Transportation
In order to have easy mobility of persons and goods, it is necessary to
have a sophisticated and widespread transportation system. This system is made
up of five primary areas of transportation, which are:
- Motor vehicles
- Railroad transportation
- Air transportation
- Water transportation
Each of these five modes consists of different subsystems which make up the
system. Each mode is used to transport persons or goods, but in many instances,
one mode may be favored over the others. All five modes require some primary
source of funds for building and maintaining the infrastructure. These funds
may come from a number of different places such as the federal government, state,
or the city through which the system runs. Different government agencies have
jurisdiction over the modes. These agencies focus on maintaining and improving
safety of each system. The individual states also have certain obligations to
the operation and regulation of the different modes of transportation.
Each mode is made up of primary subsystems. The subsystems of railroad
transportation include freight trains and passenger trains. Freight trains are
used to transport goods and materials between cities while passenger trains are
used to transport people. Although freight trains are still used all across the
nation, rail intercity freight has accounted for a decreasing share of the total
ton mileage over the past 30 years. This is mostly due to the increase in truck
transport. Rail passenger traffic had also declined over the years until better
service was offered by Amtrak and the price of fuel increased. Much of the
decline in rail passenger traffic has been due to the increasing number of air
Air transport can also be divided into the subsystems of passenger and
freight transport. Passenger air travel has rapidly increased over the years
- Increasing Gross National Product
- Increasing wealth of the middle-income groups
- Increasing number of nonprimary industry in the economic system
- Increasing amount of general aviation
- Improved technology
The areas for air transport of express and freight and mail has also increased
rapidly over the years. This is due mostly to improved technology which has
steadily lowered the cost of air transport.
Like rail and air transport, water transportation can also be broken
down to passenger and freight transport. Passenger transportation by water only
accounts for a very small percentage of water transport because it is very slow
and relatively inconvenient for most people. This is primarily used by people
for vacation purposes. Most often, water transport is used for freight movement
of items that are bulky and of low cost per unit volume.
How to Cite this Page
|Modes of Transportation in Our Body Essay - The vehicles of life, both seen and unseen, are essential to the functionality of our dynamic world. Macroscopically, cars, trains, and airplanes have the ability to transport us out of the mundane into the extraordinary. Microscopically, molecules and cells meandering their way through highways of veins and arteries form the lifeblood of humanity. A drop of blood carrying countless blood cells travels throughout our bodies delivering oxygen to tissue, helping our bodies to produce the energy it needs.... [tags: oxgyen, blood, cells, experience]||551 words|
|5 Modes Of Transportation Essays - 5 Modes of Transportation In order to have easy mobility of persons and goods, it is necessary to have a sophisticated and widespread transportation system. This system is made up of five primary areas of transportation, which are: - Motor vehicles - Railroad transportation - Air transportation - Water transportation - Pipelines Each of these five modes consists of different subsystems which make up the system. Each mode is used to transport persons or goods, but in many instances, one mode may be favored over the others.... [tags: essays research papers]||1431 words|
|Is Maritime Transportation Losing Out Its Competitive Advantage Over Other Modes Of Transportation Like Air And Road Transportation? - Abstract A sophisticated and widespread transportation mode is absolutely essential for the efficient mobility of passengers and goods. This report first investigates the various economical, cost and environmental factors specific to maritime transportation. This investigation includes a comparative analysis between maritime, land and air transport. Lastly, the growing demand in marine transportation and the multitude reasons that make shipping one of the most globalized industries in terms of freight transportation is examined.... [tags: Transportation Case Analysis]||1283 words|
|An Inside Look at Modern Seaports Essay - ... Additionally, the seaports provide for fast unloading of cargo, which is later transported via a complex maze of railroad tracks, airways and roads. A modern seaport performs a lot of functions, it is a place where not only goods are in transit but they are also sorted, manufactured and distributed. It is a multi-dimensional system; therefore it needs to be integrated within logistic chains to perform effectively (Hall, Peter, Robert and Claude 2011). An efficient seaport requires good infrastructure, superstructures and equipment.... [tags: several modes of transportation crossing point]||570 words|
| Essay on A Review of Electrical Vehicles - Four decades ago gas was on the double digits. Well now you don't have to worry about buying gas , With an electrical vehicle. The first electric car was operated in the 80s. Electrical car were popular in the late 19th century and the early 20th century, until advances in the internal combustion engine technology mass production was cheaper, Than gasoline vehicles led to the decline in the use of electric drive vehicles, The energy crisis of the 1970s and 1980s a short-lived interested in electric cars, although these cars did not reach the mass marketing stage, as in the case of 21 century.... [tags: alternative modes of transportation]|
:: 7 Works Cited
| Transportation and How it Affects Logistics Essay - Transportation is one of the largest industries in the world. It is the most costly and time consuming of the supply chain. Transportation refers to the movement of products and raw materials from one destination to another. This process begins from the supply chain to the shipping of the finished product to the consumer. For we know that products are rarely produced in the same location. We as people depend on transportation because it moves goods and people from one place to another. Transportation is a key element in the logistic chain.... [tags: pipeline, logistics, transportation, railway]|
:: 7 Works Cited
|Essay about Public Transportation Bill - Background Public transportation is serious need of a massive overhaul in this nation. We are in desperate need to catch up to the European standard of public transportation in this country. In Europe, citizens can travel across cities, bodies of water, and even counties with their state of the art public transportation system. Europeans are not nearly as reliant on cars and oil as the United States is because they have the much more practical option of taking the transportation provided to them by the government to where ever they need to go.... [tags: Public Transportation]||1155 words|
| Essay about The Role of Politics in Public Transportation - Politics plays an important role in any aspect of planning, but none such more than transport planning and the investments and policies that go in to constructing the aspects associated. As with any discipline, politics plays both positive and negative roles in public transport planning, policies and investment; as it shapes decision-making and the degrees of financial support that is given to each project. Because politics brings both positive and negative effects to public transport planning it can both promote and obstruct development.... [tags: public transport planning,politics,transportation]|
:: 10 Works Cited
| Suburbanization Produced by Technological Advances in Transportation Essay - “The new technology of the motor car became central to the development of twentieth century cities in the US” (Roberts 2009 p53) and by 1914 the US production had exceeded that of the whole of Europe. What started out as a transportation toy for the very rich in 1900 became available to ordinary working class citizens by 1920 (Roberts 2009 p55). The technologies born of the Industrial Revolution changed forever the way people in the West lived and worked and economies strengthened as a new era dawned of mass production and consumerism.... [tags: Suburbanization, Technology, Transportation, ]|
:: 11 Works Cited
|People and Public Transportation Essay - To many people public transportation is a plus. It is cheap, reliable, and it takes you anywhere you want to go. Common people use public transportation every day, to some it’s part of their daily routine, to others it is an emergency measure or just to a reliable way to travel to get somewhere they have to go. But are there any dark, secret, and negative effects that the people in our community do not think of. Many people answer yes to this question and say public transportation is death, death to our planet.... [tags: cars, society, environment]||1143 words|
Modes Transportation Transportation System Motor Vehicles Freight Passenger Trains Federal Government Rail
Pipelines can be divided into two principle classes including oil and
natural gas pipelines. Oil pipelines are used to transport oil and oil-products.
Gas pipelines differ from oil pipelines in that they are not in competition
with other carriers.
Each mode is used to convey certain goods or materials. Highways are
most often used to carry motor vehicles. These vehicles may be privately owned,
company owned, or even state owned. They may range in size from single
passenger vehicles such as motorcycles to large freight vehicles such as triple-
trailer trucks. The transport of freight may include anything from raw
materials to finished products.
Railroads are used to carry freight and passenger trains. In both cases,
the number of railroad cars may vary between destinations. However, it would
not be practical to haul a single car for a long distance , therefore, many cars
are usually hauled on each trip.
Passenger trains are designed to haul passengers, while freight trains
are designed to haul materials ranging from raw goods to finished products.
Air transport is used in the transportation of passengers and freight.
Aircraft used to transport passengers come in many different sizes. They range
from small single passenger aircraft to large jumbo jet aircraft.
Transportation of freight is another area of air transport. Most common is the
express and freight and mail carriers. Most of this material is carried by
local passenger/cargo carriers. Some military aircraft is used in the
transportation of much larger freight. The materials transported by air may
include anything from raw materials to finished products.
Another mode of transporting passengers and freight is by water. The
transportation of passengers is slow and inconvenient, therefore it is not used
very often except for pleasure. The size of water craft may vary from small
single seater jet skis to large cruise ships. The most common use of water
transportation is for freight. The type of freight moved is usually limited to
those classes that are bulky and of low cost per unit volume.
Pipelines are mainly used to transport oil and oil products or natural
gas. Oil pipelines are divided between gathering lines and trunk lines, while
gas pipelines are divided between field lines and trunk lines.
Each mode must have sufficient funds for building and maintaining the
infrastructure. For the highway system, funds come from several different areas.
The United States highway system is publicly owned, therefore much of the funds
are received from the federal government, however, most of the funds are
received from highway user taxes. Federal highway funds are available for
construction and improvement of the federal primary system. The state is
responsible for the upkeep of most primary and secondary roads. State highway
systems may overlap federal systems. The funds for most state primary systems
come from the state, while local and county authorities are responsible for
secondary systems. Local and other systems usually receive funds from the local
authorities for maintenance, improvement, and construction. Toll roads receive
funds for upkeep by charging people a small fee to travel on the highway.
Railroad systems are usually privately owned. Most railroad systems are
built and maintained by the company, but funds are also provided by the federal
The air transportation system obtains much of its funds from federal aid
if the facility is owned by local governments (in most cases they are). The
airlines themselves are also responsible for much of the funds required to
maintain the facility. Small general aviation aircraft are usually privately
owned and used for recreational purposes, or owned by businesses which do a
large amount of traveling. These facilities are usually paid for by the local
area and the users of the airport.
The construction, maintenance, and operation of waterways is paid for by
the federal government since the United States Coast Guard assumes
responsibility for the supply and operation of navigational aids. While the
federal government pays for the waterways, most of the vessels are company or
privately owned, with the exception of U.S. Coast Guard vessels. Improvement to
ports is usually is usually funded by state or city aid or from borrowing.
The pipeline transportation system is the only mode of transportation
that gets no direct aid from the federal government. Most of the funds required
to construct and maintain the pipelines comes from the company which owns the
Different government agencies from the U.S. Department of Transportation
have primary jurisdiction over each mode of transportation. The Federal Highway
Administration (FHWA) provides funds to states for highway construction,
improving, and management. FWHA also provides funds for several state-
administered safety programs. The National Highway Traffic Safety
Administration (NHTSA) focuses on maintaining and improving safety of motor
vehicles and equipment and conducts test programs to evaluate and guarantee
compliance with the standards. The Federal Railroad Administration (FRA)
develops and administers programs to achieve safe operating practices in the
industry. Primary jurisdiction of airways is controlled by the Federal Aviation
Administration (FAA). The FAA issues and enforces air safety regulations,
develops and operates the airways, and inspects and certifies aircraft. The
United States Coast Guard enforces federal laws regarding navigation, port
safety and security, inspection of vessels, and protection of the marine
environment. All construction and safety standards are enforced by the U.S.
Coast Guard. Pipeline transportation is controlled by the Federal Energy
Regulatory Commission of the Department of Energy.
Many transportation organizations exist at the state level. Each state
has certain roles in the operation and regulation of the different modes.
States must follow the regulations set by the federal government, but each state
can also make its own set of regulations. An example of this would be the N.C.
The United States transportation system is made up of several different
modes of transportation. Each of these modes are operated and regulated to
different degrees by federal, state, and local governments. All of these modes
of transportation give a great deal of mobility for the people and goods and
materials of each state.