The Wisconsin Department of Transportation (WisDOT) is preparing for the largest infrastructure improvement project the state has ever seen. Wisconsin is no stranger to construction—in the past four years WisDOT has rebuilt the $810 million Marquette Interchange in the center of downtown Milwaukee.
While the last girders are being placed on the Marquette Interchange, engineers are already planning for the next project to reconstruct and expand 35 miles of I-94 from the Illinois state line to the Airport/Mitchell Interchange in Milwaukee. Stretching through Kenosha, Racine and Milwaukee counties, the interstate plays a key role in the state’s economy. The recommended plan will improve safety, ease congestion and modernize this important transportation artery that serves approximately 1.3 million people, 28,500 businesses and 595,000 jobs in the three counties combined. About one in six residents, businesses or jobs are in close proximity to the corridor.
The I-94 North-South corridor comprises:
- Six primary traffic lanes (three in each direction) for most of its route;
- Four northbound lanes that split into east and west directions at the Mitchell Interchange, north of the Airport Spur (Rte. 119);
- Ramp and auxiliary lanes at selected interchanges;
- The Airport Spur (Rte. 119), which is a four-lane freeway facility; and
- Seventeen service interchanges outside of the Mitchell Interchange on I-94, not including the Airport Spur.
The I-94 North-South corridor was first built in the late 1950s and early ’60s. Today, safety issues, pavement and design deficiencies and traffic congestion require full reconstruction and redesign. Much of the corridor has been resurfaced three times. The Mitchell Interchange handles over 195,000 vehicles per day and includes a mixture of left and right exits. Crash rates in this interchange are up to 825% over the statewide urban average. Quick merging and weaving is necessary at the 27th Street and Airport exits. In Racine and Kenosha counties, scissor ramps also are located along the corridor and involve vehicles leaving the freeway onto a frontage road. Vehicles already on the frontage road need to stop and wait for a clearing in vehicles exiting the freeway in order to continue.
The study teams looked at several options to best improve safety on this stretch of interstate and interchanges throughout the 30-month environmental impact statement (EIS) process. With traffic projected to increase between 12% and 48% within the corridor, WisDOT’s preferred alternative is to modernize and expand the corridor from six to eight lanes. The $1.9 billion alternative offers many benefits:
- Moves ramp exits to the right side of the freeway;
- Minimizes current and future congestion, which results in fewer crashes, less waiting time and safer driving on the freeway;
- Replaces the deteriorating pavement and structures with new designs;
- Minimizes impacts to local residents and the environment;
- Provides aesthetic treatments for those who live adjacent to the freeway; and
- Constructs an additional lane in each direction.
WisDOT submitted a request for new interchanges at Drexel Avenue and Elm Road in Milwaukee County. The Federal Highway Administration (FHWA) approved this request (pending the signed record of decision [ROD], which was expected in late May).
The 27th Street interchange with I-94 will be reconstructed with U-ramps, the first of its kind in Wisconsin. This configuration will significantly improve traffic flow through the interchange. All vehicles will enter the freeway via right-hand turns off of 27th Street. The only cross traffic with 27th Street will be vehicles turning left onto 27th Street after exiting the freeway. One of the more significant changes is eliminating the maneuver to and from 27th Street and I-94 south. Motorists will be encouraged to use the Layton Avenue interchange to access 27th Street.
Three cut-and-cover tunnels are proposed for the Mitchell Interchange. A cut-and-cover tunnel consists of constructing two retaining walls along the edges of the roadway and a concrete roof on the top. Crews will excavate the area and backfill the soil against the tunnel after construction is completed. The use of a tunnel-boring machine (TBM) is not necessary because of the shallow nature of the tunnels. The tunnels will provide a more cost-effective solution than traditional bridges, and will require less traffic switches due to faster construction operations.
WisDOT also will realign the Plainfield Curve near Howard Avenue to a smoother single curve. This change will significantly improve the safety problem of the compound curve that exists today. The new curve will be designed to accommodate speeds up to 55 mph.
Into the sunset wheat
When WisDOT first started studying this corridor, residents were understandably concerned about home acquisitions. Rumors abounded that up to 150 homes would be affected. Through a comprehensive public involvement process and careful design work, the project team minimized the residential impacts to two home relocations in the city of Milwaukee and two in Oak Creek to accommodate the new interchange at Drexel Avenue.
In addition to holding over 500 meetings with individuals, community groups and local officials, the project team created three community-sensitive design (CSD) committees to help capture the character of the communities and recommend CSD treatments. The committee members served as liaisons to help WisDOT capture the community vision. The Racine and Kenosha counties’ CSD treatments will focus on the rural and natural setting surrounding the interstate. The color will be sunset wheat, with embossed street names on the bridge parapets, decorative fencing and florals on the bridges. The Milwaukee County CSD will utilize the same color scheme and will focus on simple lines, a brick-like feel on the sound-wall panels and decorative fencing with unique inserts to identify each community. The Airport Spur (Rte. 119) leading to and from General Mitchell International Airport will become a more visitor-friendly boulevard, with a mural, grasses and perennials and possible retaining wall treatments in the median. Construction is slated to begin in 2009 and will extend until 2016. Visit www.sefreeways.org for more information.