Interstate 94 in Wisconsin

Interstate 94 (I-94) runs east–west through the western, central, and southeastern portions of the US state of Wisconsin. A total of 348.23 mi of I-94 lie in the state.

Route description
The route, cosigned with US Highway 12 (US 12), enters from Minnesota just east of the Twin Cities. The route passes north of Menomonie and south of Eau Claire before turning southeast and heading toward Tomah where it joins I-90. The two Interstates run concurrently for the next 91.76 mi to Madison. I-94 enters the state as a six-lane facility which reduces to four-lanes at exit 4 (US 12).

I-94 passes by the popular tourist destination of Wisconsin Dells.

The route converges with I-39 63 mi southeast of Tomah (near Portage). This concurrency (30 mi) is the longest three-route concurrency of the Interstate Highway System and only one of two in existence. The interchanges mark a return to a six-lane configuration.

I-94 turns eastward toward Milwaukee at what is commonly known as the "Badger Interchange" where the three Interstates meet with State Trunk Highway 30 (WISS 30). The highway returns to four lanes after the interchange traffic merges, then returns to six lanes just west of Waukesha. The highway remains a six-lane facility (with various auxiliary and collector–distributor lanes in Milwaukee at interchanges) east and south of this point, and through the area is officially designated the East–West Freeway, though very few organizations, including the Wisconsin Department of Transportation's traffic control center in the area actually use that name. I-94 passes through Downtown Milwaukee, turning southbound and joining I-43 for 6 mi, into a road designated from Ozaukee County to the Illinois state line as the North–South Freeway.

I-94 leaves Milwaukee to the south, joining with I-41 at the Mitchell Interchange. These two Interstates run concurrently to the border, passing west of Racine and Kenosha on their way into Illinois toward Chicago. Traffic is heavy along this stretch.

Speed limits
The speed limit on I-94 from the Minnesota border to the Waukesha–Milwaukee county border is 70 mph. Entering Milwaukee County, the limit decreases to 55 mph. The limit is 55 mph until just west of the Marquette Interchange, where it decreases to 50 mph. This 50 mph limit continues to the Airport Interchange, where it increases to 55 mph. Between Rawson and Drexel avenues, the limit increases to 70 mph and maintains this limit to the Illinois border.

History
I-94 was the first section of the Interstate Highway System completed within the state of Wisconsin. This 1 mi section, near Johnson Creek in Jefferson County, was built in 1958. The route was added segment-by-segment over the years and was completed to its current alignment on November 4, 1969. The routing through Milwaukee displaced thousands of residents and businesses. A 1 mi stretch between Lincoln and Greenfield avenues displaced 411 homes and 45 businesses. Milwaukee continues to see millions of dollars in lost tax revenue as a result of the freeway routing through the heart of the city.

From 2004 until 2008, a portion of I-94 in Milwaukee was reconstructed as a part of the Marquette Interchange project.

Current construction
Beginning in 2009 and continuing until 2021, the 35 mi of I-94 between the Mitchell Interchange and the Illinois state line will be widened from six to eight lanes. This includes a complete rebuild of the roadway and reconstruction of frontage roads and interchanges including a new design of the Mitchell Interchange in Milwaukee County.

Auxiliary routes
Two auxiliary routes of I-94 exist in Wisconsin, both are in the Milwaukee metropolitan area. I-794 is a spur in downtown that accesses the southeast suburbs and the Port of Milwaukee. It is known as the East–West Freeway from I-94 to Lincoln Memorial Drive and as the Lake Freeway from there to Carferry Drive. I-894 is a southwest bypass of the city that is known as the Zoo Freeway from the I-94 Zoo Interchange to I-43 at the Hale Interchange and as the Airport Freeway from there to I-94 at the Mitchell Interchange.