摘要: |
Freight transportation is a vital element in the economic prosperity of any country. According to the nationwide commodity flow survey, over 12 billion tons of goods, valued at more than $11.6 trillion, were moved in America in the year 2007 (Bureau of Transportation Statistics, 2009). To continue the efficient delivery of various goods within and among the consumer markets, industry sectors, and international trade networks, public agencies and policy makers need accurate information about national freight movement. Equally important is decision makers ability to plan for the future impacts of freight traffic and evaluate the effectiveness of policies and projects designed to alleviate problems, because the volume of freight flows within the United States has almost doubled the rate of population increase over the past three decades (Transportation Research Board, 2008). Bryan et al. (2007) along with many others have argued that transportation planners should consider additional environmental, maintenance and security costs of freight transport and congestion to better formulate practical solutions. The freight shipment decision-making process is becoming even more complicated and, as the businesses increasingly adopt sophisticated supply chain management strategies, the demand for more accurate freight modeling and forecasting tools is growing. |