Major Supply Variables for Transportation Modes

The above figure represents basic supply variables for major modes categorized by routes, terminals and vehicles. Atmospheric conditions influence transport supply for all modes to various degrees (especially air transportation).

Road. Supply depends on road conditions, traffic (congestion) and its level of control (such as speed limits) and is generally measured in terms of numbers of vehicles per lane per hour. The main supply variables are road width, number of lanes, capacity of the vehicle (average number of people per vehicle in several North American cities: 1.2), speed, inventory and frequency of service (for mass transit).
Rail. The main supply variables are the number of tracks, capacity of stations and railyards, capacity of the vehicle, and speed of the vehicle.
Air. The main supply variables are capacity of airports, capacity of aircrafts, frequency of services and speed of the vehicle. The capacity of an airline corridor is enormous.
Maritime. The main supply variables are port capacity, capacity of ships, frequency of services and speed of the ship. The capacity of a maritime route is enormous.
Telecommunications. They represent a special category where the main supply variables are the capacity of transmission infrastructures (cables, antennas, satellites, etc.). Depending on the transmitted information, supply will be expressed in bps (bytes per second), in numbers of calls per unit of time or the number of minutes of available transmission (antenna) time. The development of the information highway has expended tremendously supply for the transmission of information.

Copyright © 1998-2008, Dr. Jean-Paul Rodrigue, Dept. of Economics & Geography, Hofstra University. For personal or classroom use ONLY. This material (including graphics) is not public domain and cannot be published, in whole or in part, in ANY form (printed or electronic) and on any media without consent. Permission MUST be requested prior to use.