Transportation Planning Board

Roadways

The arterial roadway system in the Madison area consists primarily of high-volume traffic roadways leading into the central Isthmus area in a radial pattern from a circumferential Beltline and Interstate route system. The system also includes several north-south roadways, completing the grid network of arterial roadways in the area.

The roadway system is functionally classified into four groups or classes of roadways according to their function, traffic volumes, and the type of service they provide. The four classes are: principal arterials, minor arterials, collectors, and local roadways. Principal arterials are further subdivided into the Interstate system, other freeways, and others. The roadway system is also divided into two groups—urban and rural—based upon whether the roadway is located within the urban area of a metropolitan area or not. The functional classification provides a basis for receipt of federal transportation funding. In 2012, the MPO and WisDOT initiated an update to the regional roadway functional classification system. This update corresponded with the U.S. Census Bureau’s release of the new 2010 urbanized area boundaries and the designation of the new Madison Urban Area and Planning Area boundaries, all of which occurred in 2012. WisDOT and FHWA have approved the new Urban Area and Planning Area boundaries.

Traffic Growth and Congestion

The growth of major employment and commercial retail centers on the periphery of the Madison area—most of them located outside the Beltline and Interstate system—has led to a more dispersed travel pattern with a lower percentage of trips destined for the central area. The combination of development growth and increased trip making and daily vehicle miles of travel (VMT) per person has over time led to increased congestion on metropolitan area roadways. The map below shows the arterial roadway segments that were congested during peak periods in 2006 in the metropolitan area. There were 229 center lane miles of arterial roadways that were congested and 74 center lane miles that were very congested during peak periods. Traffic conditions haven’t changed significantly at the regional level since this time.

The increase in traffic volumes over the past three decades has been especially large on the Beltline and Interstate route system and on radial arterials beyond this system that lead into the Madison area, such as USH 151, Verona Road (USH 18/151), USH 12/18, USH 14, and Mineral Point Road (CTH S). From 1980 to 2011, average traffic volumes on the Beltline and Interstate system increased 211% from 29,500 to 91,700. From 1980 to 2011, average traffic volume on the radial arterials beyond this system increased 238% from 12,900 to 43,600. In both cases, the rate of traffic growth was the fastest during the 1980s. However, volumes have continued to increase at a steady rate. Since 1999-2000, volumes increased 22% on the Beltline and Interstate system and 21% on the radial arterials. The circumferential Beltline and Interstate system has helped to alleviate traffic growth on cross-Isthmus arterials, such as the Johnson/Gorham and Atwood/Williamson Street corridors, Monroe Street, and University Avenue. Average traffic volume on cross-Isthmus arterials increased only 13% from 21,400 to 24,200 from 1980 to 1990 and has remained essentially unchanged since then at 24,700 in 2011 after reaching 27,700 in 2000. The lack of any net increase in employment in the downtown/UW campus area has also limited traffic growth. These roadways remain congested during peak periods.

The economic downturn since 2008 and the high price of gasoline have contributed to an overall decrease in vehicle miles of travel (VMT) countywide from 2007 to 2011, according to estimates prepared by the Wisconsin Department of Transportation based on traffic counts and gasoline sales. The estimated daily VMT in Dane County in 2011 was 13.12 million, a 1.1% decrease compared to 2010 and 3% lower than in 2007.

The MPO has calculated VMT on City of Madison arterial and collector roadways the past few years. This data also shows the overall recent downward VMT trend. The weekday VMT total was 4.76 million in 2011, a 1.5% drop compared to 2008. Aside from continuing relatively high unemployment, other factors that are believed to be affecting VMT trends (at least nationally) are the aging population with older people driving less and the growing ability to work remotely in the Internet era. There has also been discussion of the desire of the younger generation (under age 35) to live in central urban areas and drive less. A recent national study found that from 2001-2009 the average number of miles traveled by persons aged 16-34 dropped 23% to 7,900 per capita. The high bus ridership by young Epic Systems employees commuting from central Madison to Verona is evidence of this.