Freight Facts and Figures 2008

Figure 3-10. Peak-Period Congestion on High-Volume Truck Portions of the National Highway System: 2002

Congested highways carrying a large number of trucks substantially impede interstate commerce, and trucks on those segments contribute significantly to congestion. Recurring congestion slows or stops traffic on over 6,300 miles of the NHS that carry more than 10,000 trucks per day.

Figure 3-10. U.S. map showing heavy congestion in the largest cities and moderate congestion on intercity routes in California.

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Note:

High-volume truck portions of the National Highway System carry more than 10,000 trucks per day, including freight-hauling long-distance trucks, freight-hauling local trucks, and other trucks with six or more tires. Highly congested segments are stop-and-go conditions with volume/service flow ratios greater than 0.95. Congested segments reduce traffic speeds with volume/service flow ratios between 0.75 and 0.95.

Source:

U.S. Department of Transportation, Federal Highway Administration, Office of Freight Management and Operations, Freight Analysis Framework, version 2.2, 2007.

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