As a nation of heavy drivers, it is not surprising that we have an awful lot of paved roads. The market size presented here is for miles of paved, public roads in the United States. The chart shows how those roads are broken down by type: interstate freeways, other highways (arteries), smaller roads feeding the highway system (collector roads), and local roads.

Geographic reference: United States
Year: 2008
Market size: 4,042,778 miles
Source: “Table 1-1: Public Road Length, Miles by Functional Systems: 2008,” State Transportation Statistics 2009, page A-1.
Original source: Research and Innovation Technology Administration, Bureau of Transportation Statistics, U.S. Department of Transportation