Interstate 94 (I-94): Billings to Port Huron Route and Safety Data

How long is I-94?

Wikipedia and Interstate Guide both put I-94 at 1,555.43 miles from end to end. The January 2026 FHWA Route Log credits it with far less, 1,441.77 miles, which places it ninth among the main Interstates.

Shared pavement accounts for the gap. The Route Log books a mile used by two Interstates to only one of them, and I-94's overlap notes list 153.95 shared miles. Most are in Wisconsin, where I-94 shares 91.76 miles with I-90 between Tomah and Madison and 25.5 miles with I-41 in the southeast of the state. In Illinois it gives up 15.39 miles to I-90 and 2.48 to I-80, while the 2.5 miles it shares with I-41 near the state line stay in its own row. In Indiana, 16.05 miles go to I-80, and in St. Paul, 0.27 miles go to I-35E. That leaves Wisconsin with a Route Log row of 218.68 miles. The row plus its overlap notes comes to 335.94, and Wikipedia gives 341.02.

Counted the way this page's crash rates count them, I-94 totals 1,598.30 miles. Interstate Guide's state table sums to 1,595.72. Wikipedia's state figures come to about 40 miles less, mainly because it lists Montana at 219.38 miles where the Route Log has 249.61 and Illinois at 61.53 where the shared-mile count gives 77.44. North Dakota has the longest stretch, 352.38 miles. Indiana has the shortest, 30.16 miles in the Route Log or 46.21 with the I-80 overlap included.

Where I-94 starts and ends

The western end is a junction with I-90, US 87 and US 212 at Lockwood, just east of Billings, Montana. The eastern end is the Blue Water Bridge at Port Huron, Michigan. I-69 joins I-94 for the last few miles, about 4, to the border, and on the Canadian side the road becomes Ontario Highway 402 at Point Edward. Wikipedia describes I-94 as the only east-west Interstate with a direct connection to Canada.

In western North Dakota the road runs through the Badlands near Medora, close to the South Unit of Theodore Roosevelt National Park, then crosses the Missouri River between Mandan and Bismarck and the Red River between Fargo and Moorhead. Minnesota's section passes St. Cloud, goes through Minneapolis and St. Paul, and crosses the St. Croix River from Lakeland into Hudson, Wisconsin. After Eau Claire, Madison and Milwaukee, I-94 approaches Chicago on the Edens Expressway, joins I-90 on the Kennedy and Dan Ryan expressways, and heads into Indiana on the Kingery and Borman expressways. Its Michigan miles pass Benton Harbor, Kalamazoo, Battle Creek and Ann Arbor before reaching Detroit on the Detroit Industrial Freeway, which goes by Detroit Metro Airport at Romulus, and the Edsel Ford Freeway.

Interstate junctions along I-94

The list roughly follows I-94 from Montana east to Michigan. I-90 appears five times: at the western end near Billings, twice in Wisconsin where the two share lanes from near Tomah to Madison, once in Illinois for their stretch together through Chicago, and once in Indiana. I-39 joins the pair from Portage to Madison. I-41 is listed twice in Wisconsin and I-69 twice in Michigan, the second time where it joins I-94 for the final run to the Blue Water Bridge. The Minnesota entry for I-35 includes the short overlap with I-35E in St. Paul, and I-80 shares I-94's lanes from Illinois into Indiana. Illinois adds crossings with I-55 and I-57, and Michigan adds I-96 and I-75.

Fatal crashes on I-94

From 2020 to 2024, crashes on the I-94 main line killed 451 people, about 90 a year. That works out to 5.6 deaths a year for every 100 route miles, lower than the 9.5 average across the Interstate network, and ranks I-94 43rd of the 56 routes long enough to rate, where 1 has the highest rate. Deaths went from 87 in 2020 to 106 in both 2021 and 2022, then fell to 86 in 2023 and 66 in 2024, the fewest in the five years.

Illinois has the highest rate on the route by a wide margin, 28.4. Its 110 deaths over 77.44 route miles, a count that includes the stretches shared with I-90 and I-80, are about a quarter of the route total, and Cook County alone had 96. Wayne County, Michigan, had the next most with 51, followed by Macomb County at 19 and Washtenaw County at 17, both in Michigan, and Hennepin County, Minnesota, also at 17. Michigan's rate is 10.7 and Indiana's 8.2. Rates are lower west of Chicago: 3.9 in Wisconsin, 4.4 in Minnesota, 2.1 in North Dakota and 1.3 in Montana, the lowest of the seven states.

Wisconsin's rate spreads its 67 deaths over 341.02 miles, Wikipedia's length for I-94 in the state. The Route Log row of 218.68 miles leaves out the stretches I-94 shares with I-90 and I-41, so it would make the state's rate look higher than the road's record.

Counties with the most I-94 crash deaths

Bridges on I-94

The 2025 National Bridge Inventory counts 887 bridges on the I-94 main line, with a median build year of 1968. Of those, 25 rate Poor, about 2.8 percent, and 595 rate Fair. Wisconsin has the most bridges at 248 and the most in Poor condition at 7. Michigan, Minnesota and Illinois have 5 Poor bridges each, and Illinois has the highest share, 5 of its 51.

Milwaukee's Marquette Interchange, first opened in December 1968, was rebuilt from 2005 to 2008 for $810 million. In Minneapolis, I-94 runs through the Lowry Hill Tunnel, a cut-and-cover tunnel about 1,500 feet long that opened in late 1971. Hazardous cargo is not allowed inside. Farther east the road crosses the Mississippi on the Dartmouth Bridge, between Cedar-Riverside and the University of Minnesota. At Port Huron, FHWA files the two spans of the Blue Water Bridge as separate facilities.

Tolls on I-94

FHWA's January 2023 toll inventory lists three facilities on I-94. The Tri-State Tollway charges drivers from the Wisconsin line to the I-94/I-294 split, and the Edens Spur that carries I-94 from there toward the Edens Expressway is tolled as well. The other two entries are the Blue Water Bridge's spans to Point Edward, Ontario, which only drivers crossing the border pay. Someone driving from Billings to Port Huron without entering Canada pays tolls only in the northern Chicago suburbs.

FHWA's 82.81 miles for the Tri-State cover the whole tollway from Russell Road to its southern end at SR 394, and I-294 alone accounts for 48.1 of those miles. The two Blue Water spans are listed at 1.5 and 1.24 miles, measured from Port Huron to Point Edward.

I-94 auxiliary routes

I-94 has seven three-digit routes. Minnesota has three of them around the Twin Cities: I-494, at 42.82 miles, serves Bloomington, Eden Prairie, Maple Grove and Minnetonka; I-694 covers 23.11 miles through Maplewood, Roseville and Fridley; and I-394 runs 9.75 miles from Minneapolis through St. Louis Park and Golden Valley. Illinois has the longest, the 48.1-mile I-294, which serves Chicago suburbs including Harvey, Westchester and Oak Lawn. Milwaukee has two short ones, I-794 and I-894, and I-194 exists twice, as a 1.05-mile spur in Bismarck and a 3.45-mile road in Battle Creek.

When I-94 was built

A few pieces of I-94 opened before the Interstate system existed. Chicago's Kingery Expressway dates to 1950 and the Edens Expressway to 1951. In Detroit, the 1953 interchange with the Lodge Freeway is described as the first full-speed freeway-to-freeway interchange in the United States. The I-94 number dates to August 14, 1957. The first section paid for with Interstate funds, between Jamestown and Valley City, North Dakota, opened on October 16, 1958, and Chicago's Dan Ryan Expressway followed on December 15, 1962.

Most of southern Michigan's I-94 was open by 1962, though the link to Indiana waited until 1972. North Dakota dedicated its completed route on August 7, 1970. Minnesota opened the Minneapolis to St. Paul segment in 1968 and its final section, from Woodbury to the Wisconsin line at Lakeland, in 1985. Montana four-laned its last two-lane stretch the same year. Detroit's portion carried the Edsel Ford Freeway name on its signs until the late 1980s.

Building I-94 through St. Paul displaced the Rondo neighborhood, until then the city's largest Black community. MnDOT started its Rethinking I-94 study of the Minneapolis-St. Paul stretch in 2016 and in 2025 dropped the option of replacing the freeway with a street-level boulevard. In Wisconsin, WisDOT began construction in late 2025 on its I-94 East-West project, about 3.5 miles between 70th and 16th streets in Milwaukee.

I-94 traffic and road conditions

Each of the seven states keeps its own map of crashes, closures and road conditions for I-94. The links below start with Montana and end with Michigan, so pick the one for where you are on the road right now.

I-94 questions