New Report Shows Effects of Traffic Congestion on Travel Times

The Wisconsin Department of Transportation (WisDOT) released new data Aug. 13 showing that 8 of 20 Milwaukee area freeway segments are so congested that motorists must allow twice as much time to consistently complete their trips during peak travel times as they would under uncongested conditions. The data is contained in WisDOT’s first “Travel Time Reliability and Delay” report, which details travel time and delay data for urban and rural corridors throughout Wisconsin.

While the report showed some improvements in hours of delay statewide when comparing spring 2013 with spring 2014, user delays and the cost of the delay is significant. During a one year period, drivers in Wisconsin experienced a total of 7.4 million hours of traffic delay, with a corresponding cost of $226.5 million.

The report uses recorded traffic data to measure the extra time a motorist must plan into their trip to be assured of consistent on-time arrival at their destination during congested travel periods. Segments with high multiples of peak vs. normal travel time are considered “unreliable.”

According to the report, the most unreliable trips are for travel on the Milwaukee area freeway system. For travel westbound on I-894 from the Hale Interchange to the Zoo Interchange motorists must allow nearly 17 minutes in the morning hours to consistently complete what is a 7-minute trip without congestion. Travelers on southbound US 45 from the Waukesha County line to the Zoo Interchange must allow 22 minutes in the afternoon for what is a 9-minute trip without congestion. Planning time indexes for other Milwaukee and Madison area freeway segments are summarized in the report.

WisDOT is currently studying potential improvements to relieve congestion on two of the most congested segments in the Milwaukee region: I-94 between the Marquette Interchange and the Zoo Interchange, and I-43 between Silver Spring Drive and Highway 60.

The travel time reliability and delay report is a component of WisDOT’s MAPSS Performance Improvement Program, which measures key information in the five core goal areas of Mobility, Accountability, Preservation, Safety and Service.