|Length||1,585.20 mi (2,551.13 km)|
|West end||/ / near Billings, MT|
|East end||at Canadian border on Blue Water Bridge in Port Huron, MI|
|States||Montana, North Dakota, Minnesota, Wisconsin, Illinois, Indiana, Michigan|
Interstate 94 (I-94) is an east-west Interstate Highway connecting the Great Lakes and northern Great Plains regions of the United States. Its western terminus is in Billings, Montana, at a junction with I-90; its eastern terminus is in Port Huron, Michigan, where it meets with I-69 and crosses the Blue Water Bridge into Sarnia, Ontario, Canada, where the route becomes Ontario Highway 402. It thus lies along the primary overland route from Seattle (via I-90) to Toronto (via Ontario Highway 401), and is the only east-west Interstate highway to form a direct connection into Canada. I-94 intersects with I-90 several times: at its western terminus; Tomah to Madison in Wisconsin; in Chicago, and in Lake Station, Indiana. All together the major cities that I-94 connects to are Billings; Fargo, North Dakota; Minneapolis-Saint Paul; Madison; Milwaukee; Chicago; and Detroit.
I-94 begins at Billings and travels northeastward toward Glendive before exiting the state to the east. I-94 links seven counties, which are Yellowstone, Treasure, Rosebud, Custer, Prairie, Dawson, and Wibaux counties and passes near or through Miles City, and Glendive while connecting with I-90 in Billings. The highway is notable for following the Yellowstone River from Billings through Glendive. Beyond the western terminus of I-94, I-90 connects westbound I-94 travelers to points west such as Butte, Coeur d'Alene, Idaho and Seattle, Washington.
The route enters at Beach and passes through the Badlands near Medora (near the Theodore Roosevelt National Park South Unit). A public rest area about seven miles (11 km) east of Medora provides an awe-inspiring view, especially at sunset, and an opportunity to hike through some of the scenery on the Painted Canyon Trail. Further east, I-94 provides access to the North Unit of Theodore Roosevelt National Park, then passes through the cities of Dickinson, Mandan, Bismarck, Jamestown, and Valley City on the way to West Fargo and Fargo, where it leaves the state and crosses into Minnesota. Throughout the state, the route generally travels relatively straight east and west following both the railroad route and the former route of US Highway 10 (US 10, called "The Old Red Trail") where its western terminus is at exit 343 in West Fargo.
The highway intersects with the Enchanted Highway 11 miles (18 km) east of Dickinson at exit 72. At New Salem, it passes Salem Sue, a 38-foot-high (12 m) sculpture of a Holstein cow and is clearly visible from I-94 on the south side of the road. A drive up the road to Sue will take visitors to a vantage point where they can see a panoramic landscape for many miles. Between Mandan and Bismarck, I-94 crosses the Missouri River with a view of the Northern Pacific/BNSF Railroad Bridge on the south side of the road. At Steele, it passes the world's largest sculpture of a sand hill crane (named Sandy), which is 40 feet (12 m) tall and visible from I-94 on the south side of the road, just to the east of exit 200. At Jamestown, it passes the world's largest sculpture of the buffalo (actually bison) named "Dakota Thunder", which is 28 feet (8.5 m) tall and is visible from I-94 on the north side of the road. US 52 is concurrent with I-94 from Jamestown to the Minnesota state line. approximately mile marker 275 on the westbound lanes between Jamestown and Valley City, there is a small green sign marking the Laurentian Divide, which marks a continental divide where rivers south of the divide drain into the Gulf of Mexico, while the rivers north flow into the Arctic Ocean. The highway reaches Fargo, before the Red River.
Leaving Fargo and entering Moorhead, Minnesota, I-94/US 52 crosses the Red River. East of the Moorhead airport, the Interstate travels in a northwest-southeast trajectory past Fergus Falls, Alexandria, and St. Cloud on the way to the Twin Cities, and eastward out of the state.
The road crosses the Mississippi River in Minneapolis between the Prospect Park and Seward neighborhoods. The highway joins Minneapolis and St. Paul together where it meets Minnesota Highway 280. US 52 leaves I-94 after being concurrent with I-94 from the North Dakota State Line, and heads southbound towards Rochester
In the Twin Cities, the routing of the highway is politically charged, primarily through many historic working-class and African-American neighborhoods. In Saint Paul, the routing of I-94 is set through and displaces the historic Rondo neighborhood, which prior to the highway construction was the largest African-American community in Saint Paul.
I-94 enters Wisconsin east of the Twin Cities at Hudson. It passes Eau Claire before turning southeastward and joining with I-90 in Tomah and I-39 in Portage. I-94 leaves I-90 and I-39 near Madison and resumes its easterly path toward Milwaukee before turning south and heading to Chicago, entering Illinois at Pleasant Prairie.
In the state of Illinois, I-94 runs south from Wisconsin to Indiana via downtown Chicago. It is tolled on the Tri-State Tollway to the I-94/I-294 split; it then runs east to the Edens Expressway, where it turns south through the city of Chicago. At I-80, I-94 runs east to Indiana on the Kingery Expressway.
In the state of Indiana, I-94 runs east from Illinois concurrently with I-80. It crosses Interstate 90 (Indiana Toll Road), where I-80 joins I-90 east towards Ohio. I-94 continues northeasterly, paralleling the Lake Michigan shoreline into Michigan. The 55-mile-per-hour (89 km/h) speed limit used to continue east of exit 26; now it ends a mile east of I-80/I-90, where the speed limit goes up to 70 miles per hour (110 km/h) on eastbound I-94. Between mile markers 0.0 and 15.5, the highway is also posted along with I-80. Between mile markers 15.6 and 19.0, I-94 is posted alone.
I-94 runs north along Lake Michigan to St. Joseph and Benton Harbor before heading east toward Detroit. It turns northeast to Port Huron where it meets I-69 and ends at the Blue Water Bridge, where it becomes Ontario Highway 402 in Point Edward, Ontario.
The first section of I-94 completed with Interstate funds (under the Federal-Aid Highway Act of 1956) was a 12-mile (19 km) section between Jamestown and Valley City, North Dakota in 1958.
North of Chicago, I-94 has been widened from six to eight lanes from Illinois Route 22 (IL 22, Half Day Road) to just south of the Wisconsin state line at IL 173 and 95th Street to 159th Street. Construction began in 2009 to completely rebuild I-94, including expansion to eight lanes, from the Wisconsin-Illinois border through the Mitchell Interchange in Milwaukee. This construction is expected to be completed in 2021.
In 2005, the I-94 bridge over the Crow River near St. Michael, Minnesota, about 35 miles (56 km) northwest of Minneapolis, was rebuilt. In 2006, a project to widen I-94 east of downtown St. Paul between Minnesota State Highway 120 and McKnight Road from four to six lanes was completed.
The interchange at 95th Ave. N in Maple Grove, Minnesota, was rebuilt with a new, wider bridge that replaced the two-lane bridge there, which was demolished in July 2006.
In Detroit, I-94 was routed over the existing Edsel Ford Freeway and remained signed as such until the late 1980s when Michigan deemphasized proper names on Interstate guide signs. Its interchange with the Lodge Freeway, built in 1953, is significant as the first full-speed freeway-to-freeway interchange built in the United States.
From September 2007 to October 2008, the Minnesota Department of Transportation (Mn/DOT) added a temporary extra lane to I-94 between northbound I-35W and Minnesota State Highway 280 in the Twin Cities to help relieve traffic congestion caused by the collapse of the I-35W Mississippi River bridge. As a result, this portion of I-94 was not up to Interstate Highway standards during this time period.