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8:00am to 4:30pm
121 S. Pinckney St.,
Madison, WI 53703
Tel: (608) 266-4336
Fax: (608) 261-9967
The arterial roadway system in the Madison metropolitan area consists of high traffic volume roadways leading into the central Isthmus area in a radial pattern from a circumferential Beltline and Interstate route system. The arterial system also includes several north-south roadways (e.g., Stoughton Rd./USH 51 on the east side and Midvale Blvd. and Gammon Rd. on the west side), completing the 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. Following the U.S. Census Bureau’s release of the new 2010 urbanized area boundaries in 2012 and the designation of the new adjusted Madison urban area and planning area boundaries by the MPO, the MPO will update the regional roadway functional classification system.
Traffic Growth and Congestion
The growth in households, population, and employment discussed above has led to increasing traffic volumes and congestion levels on regional roadways. The growth in traffic volumes over the past 30+ years has been particularly evident on the Beltline and Interstate route system and on the radial arterials beyond this system leading into the Madison area (e.g., USH 151, USH 18/151, USH 12/18, USH 14, and CTH S). The traffic growth was fastest during the 1980s, but continued to grow until the past several years with the downturn in the economy and amount of land use development and higher gas prices. Traffic on most cross-Isthmus arterials has not increased significantly in the past couple of decades with the exception of East Washington Avenue. This is due in part to the lack of employment growth in the downtown area and also to the congestion on these roadways, which has diverted traffic to other routes, particularly the Beltline.
There are 229 center lane miles of arterial roadways that are congested and 74 miles that are very congested based on this 2006 data. Much of the congestion and delay on signalized urban arterial streets occurs at the intersections.
The downturn in the economy and the record high price of gasoline in 2008 resulted in a 4.3% decrease in vehicle miles of travel (VMT) in Dane County according to WisDOT estimates. VMT started to increase again in 2009 and 2010, but has yet to reach the level in 2006. From 2000 to 2006, VMT had increased an average of about 1.5% per year.
The county VMT estimates prepared by WisDOT are based on calculation of a state VMT control total based on gasoline sales (and fleet fuel efficiency). County estimates are calculated based changes in traffic counts on automated traffic recorders, available traffic counts on state highways and local roadways, and an estimation of “remainder” VMT on local roadways where counts aren’t available. MPO staff has developed a methodology for calculating the average weekday VMT on the collector and arterial roadway system within the City of Madison using actual and imputed traffic counts multiplied by the roadway segment length. The City of Madison collects traffic counts on about half of the system each year. The estimated 2010 weekday VMT on this system within the city was 4,738,100, almost the same as in 2009.