Cal Poly Pomona
Figure 1. National Natural Gas Pipeline Network, 2000
The major trunklines of the U.S.’ crude oil pipeline network are shown in Figure 2. A large concentration of pipelines emanates from the ports adjacent the offshore drilling platforms along the Gulf Coast. Trunklines extend from the Texas coast to Illinois, Ohio and Indiana. One trunkline runs north-south through central California, extending from Los Angeles to the Bay Area. The network extends into Canada to incorporate several trans-border pipelines. The network of refined (petroleum) products pipelines is shown in Figure 3. This network is separate from and in addition to the crude oil pipelines. A heavy concentration of the refined products pipelines is in the midwestern U.S., particularly Illinois, Indiana, Missouri, Iowa, Kansas, and a few other States.
Aircraft were used to transport about 4% of the value and 1% of the tonnage of goods in the U.S. in 2002. A total of 37 billion ton-miles of goods were moved by aircraft in the U.S. in 2004. Despite the large value, aviation is a “distant fifth” to the four primary freight modes – trucks, railroads, maritime and pipelines – in terms of goods movement in the U.S. Aircraft do, however, carry over 25% of the value of all U.S.-international merchandise. Similarly to maritime, aviation’s role in freight transport can be separated into two groups: airports and air carriers. Also, as with maritime, the airport and air carrier owners and operators are different.