Freight Facts and Figures 2008

Figure 3-8. Peak-Period Congestion on the National Highway System: 2002

Recurring congestion caused by volumes of passenger vehicles and trucks that exceed capacity on roadways during peak periods is concentrated primarily in major metropolitan areas. In 2002, peak-period congestion resulted in traffic slowing below posted speed limits on more than 10,600 miles of the NHS and created stop-and-go conditions on an additional 6,700 miles.

Figure 3-8. U.S. map showing heavy congestion in major cities and moderate congestion on intercity routes in California and Florida.

[JPEG 398KB, PDF 2.3MB]

Note:

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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