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 passengers.
Air transport can also be divided into the subsystems of passenger and freight transport. Passenger air travel has rapidly increased over the years due to:
- 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.
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...