The entire length of I-94 is listed on the National Highway System, a network of roadways important to the country's economy, defense, and mobility. The freeway carried 168,200 vehicles on average between I-75 and Chene Street in Detroit, which is the peak traffic count in 2015, and it carried 12,554 vehicles immediately west of the Blue Water Bridge in Port Huron, the lowest traffic count in 2015. As the state trunkline highway closest to the lake shore in these areas, I-94 carries the Lake Michigan Circle Tour south of Benton Harbor–St. Joseph and the Lake Huron Circle Tour in the Port Huron area. Sections through the Detroit area are named the Detroit Industrial and Edsel Ford freeways. I-94 in the state is either a four- or six-lane freeway for most of its length; one segment in the Detroit area has up to ten lanes total near the airport.
I-94 enters Michigan from Indiana south of New Buffalo. The freeway runs northeasterly through rural Michiana farmland in the southwestern corner of the Lower Peninsula and parallels the Lake Michigan shoreline about three miles (4.8 km) inland. I-94 traverses an area just east of the Warren Dunes State Park as the freeway runs parallel to the Red Arrow Highway, a former routing of US Highway 12 (US 12) named after the 32nd Infantry Division (Red Arrow Division). The freeway crosses its companion highway south of St. Joseph; Red Arrow turns northward carrying the business loop for Benton Harbor and St. Joseph (Business Loop I-94, BL I-94). The Interstate curves further inland to bridge the St. Joseph River near Riverview Park. East of Benton Harbor, I-94 meets the Napier Avenue interchange, where US 31 merges onto the freeway. East of the Southwest Michigan Regional Airport, I-94/US 31 meets the southern end of I-196; US 31 departs the I-94 freeway to follow I-196, and I-94 continues its course away from Lake Michigan.
I-94 at Park Road near Coloma
South of Coloma, the trunkline turns eastward and roughly follows the Paw Paw River on a course that takes it south of Watervliet and Hartford. Between the latter two cities, the freeway transitions from northeastern Berrien County into western Van Buren County. It curves around and between Lake Cora and Threemile Lake near the junction with the northern end of M-51. About four miles (6.4 km) further east, I-94 crosses M-40 south of Paw Paw. Continuing eastward, the Interstate runs through Mattawan before entering western Kalamazoo County.
In Texas Township, the freeway enters the western edges of the Kalamazoo suburbs. South of the campus for Western Michigan University's College of Engineering & Applied Sciences in Portage, I-94 intersects US 131. Near the Kalamazoo/Battle Creek International Airport, the Interstate passes into the southeastern corner of Kalamazoo before entering Comstock Township. The freeway intersects the eastern end of Business Spur I-94 (BS I-94) at a partial interchange near Morrow Lake in the township. I-94 continues out of the eastern Kalamazoo suburbs, paralleling the Kalamazoo River through the Galesburg area. Before crossing into Calhoun County on the west side of Battle Creek, I-94 has the only driveway on any of Michigan's Interstate Highways for a gate providing access for military vehicles into the Fort Custer Training Center.
The Interstate enters Calhoun County southwest of the W. K. Kellogg Airport and enters the city of Battle Creek. Immediately east of the county line, the freeway has an interchange with the western end of Battle Creek's business loop. Next to the Lakeview Square Mall, I-94 meets its only auxiliary Interstate in Michigan: I-194. I-94 turns to the northwest to round Beadle Lake, intersecting M-294 before spanning the Kalamazoo River. East of the river crossing, the freeway meets an interchange for M-96, M-311 and the eastern end of the Battle Creek business loop near the FireKeepers Casino Hotel in Emmett Township. Turning back eastward, The Interstate exits the eastern Battle Creek suburbs and continues to an interchange with I-69 near Marshall; the business loop for Marshall follows I-69 southward.
Into Metro Detroit
Continuing eastward, I-94 traverses rural land on the north side of Marshall. The freeway runs north of, and parallel to, the Kalamazoo River through eastern Calhoun County. It angles southeasterly toward Albion before returning to an easterly course on the north side of town. I-94 crosses into western Jackson County before intersecting M-99. From there, it runs generally due east with a jog around Parma. West of the county airport, the Jackson business loop follows M-60 southward, and I-94 travels through the north side of Jackson. North of downtown, US 127 merges in from the north and runs concurrently with I-94 around the city. Southeast of the Michigan State Prison, US 127 departs to the south, and I-94 continues eastward through the rest of the county.
The freeway runs north of the Chrysler Chelsea Proving Grounds in Chelsea next to the M-52 interchange. As I-94 continues easterly, it passes into the western edge of the Ann Arbor area. West of downtown, the M-14 freeway splits off to the northeast, and the Interstate turns to the south and southeast to curve around the south side of the city. The freeway passes between Briarwood Mall and the Ann Arbor Municipal Airport. On the southeastern corner of Ann Arbor, I-94 intersects US 23 and continues around the south side of Ypsilanti. South of that city, the freeway also carries US 12 and crosses the Huron River north of the river's mouth at Ford Lake. I-94 jogs southeasterly around the south side of the Willow Run Airport complex, separating from US 12 and entering Wayne County.
I-94 as seen from the air near Detroit Metropolitan Wayne County Airport
South of Willow Run, the Interstate parallels the north shore of
Belleville Lake. East of the water body, it intersects I-275 near the northwest corner of Detroit Metropolitan Wayne County Airport and angles northeasterly through the southwestern Detroit suburbs along the Detroit Industrial Freeway. I-94 uses the Gateway Bridge over the single-point interchange at US 24 (Telegraph Road) in Taylor; these bridges were inspired by Super Bowl XL and provide a western entrance to the city. Further east, the Interstate intersects M-39 (Southfield Freeway) and passes the Uniroyal Giant Tire in Allen Park. I-94 then turns to the northeast through the Ford River Rouge Complex in Dearborn before turning back easterly on the Edsel Ford Freeway into Detroit.
I-94 traverses Detroit in an east–west direction well inland of, and parallel to, the Detroit River. The freeway intersects I-96 (Jeffries Freeway) and M-10 (Lodge Freeway) on the West Side, passing the main campus of Wayne State University before entering the East Side at M-1 (Woodward Avenue). Immediately east of the interchange with I-75 (Chrysler Freeway), I-94 forms the southern border of the Milwaukee Junction district. The Edsel Ford Freeway continues through residential neighborhoods of Detroit's East Side. The Interstate turns more northerly, mimicking the shoreline of Lake St. Clair, and exits Detroit for Harper Woods. Just north of the interchange for M-102 (Vernier Road), the freeway crosses 8 Mile Road and enters Macomb County.
North to Canada
Running northward through Macomb County, I-94 meets the eastern end of I-696 (Reuther Freeway) about three miles (4.8 km) north of the county line in St. Clair Shores. The freeway continues to parallel the lakeshore, and travels to the west of Selfridge Air National Guard Base in Harrison Township. It turns back to the northeast at 23 Mile Road at the interchange with M-3 and M-29. North of 26 Mile Road, the freeway exits the northern suburbs and passes into farmland in The Thumb region.
I-94 eastbound approaching exit 271 in Port Huron
South of Michigan Meadows Golf Course, I-94 crosses County Line Road and enters St. Clair County. The freeway continues northeasterly as far as Marysville before turning northward near the St. Clair County International Airport. From there, it runs roughly parallel to the St. Clair River. The Interstate travels along the western edge of residential areas for Marysville and Port Huron as it continues northward. Immediately west of downtown Port Huron, it intersects I-69; the two freeways merge and turn first east and then north through an interchange that also features connections to BL I-69.
I-94/I-69 turns back to the east about a mile (1.6 km) north of their confluence to span the Black River north of downtown. On the eastern bank of the river, there is one final interchange for M-25 and BL I-69/BL I-94 before the freeway reaches the toll and customs plazas for the twin-span Blue Water Bridge. Past these plazas, I-94/I-69 ascends the approach to the bridge which crosses the St. Clair River to Point Edward (Sarnia), Ontario. At the international boundary at the center of the river, the Interstate designations jointly terminate, becoming Ontario Highway 402.