There are currently eight business routes of Interstate 94 (I-94) in the US state of Michigan. These business routes connect I-94 to the downtown business districts of neighboring cities. Seven of the eight routes are business loops which bear the Business Loop I-94 (BL I-94) designation while one is a business spur that bears the Business Spur I-94 (BS I-94). These loops are former routings of I-94's two predecessors in Michigan: US Highway 12 (US 12) or US 25. The westernmost BL I-94 runs through the twin cities of Benton Harbor and St. Joseph along the former routing of US 12 and US 31/US 33 that now includes a section of the Lake Michigan Circle Tour in the state. The loops in Kalamazoo, Battle Creek, Marshall, Albion, and Jackson were also formerly segments of US 12 which were later designated as separate version of Business US Highway 12 (Bus. US 12) through their respective cities before becoming BL I-94s in 1960. The BL I-94 in Kalamazoo was converted into BS I-94 in 2019. The route of the business loop through Ann Arbor was previously US 12 and then later M-14 before receiving its current moniker. The BL I-94 through Port Huron was previously US 25 and then Business US Highway 25 (Bus. US 25). __TOC__
Benton Harbor–St. Joseph
Business Loop Interstate 94 (BL I-94) is a state trunkline highway and business loop that runs from I-94 through the downtowns of Benton Harbor and St. Joseph. The highway begins at exit 23 on I-94 in Lincoln Township where it runs along Lakeshore Drive, passing through the community of Shoreham. This section of the loop has five lanes (two in each direction with a center turn lane) before it drops a lane in each direction south of Shoreham, and it is part of the Lake Michigan Circle Tour (LMCT). BL I-94 briefly runs concurrently with M-63 along Main Street in downtown St. Joseph. This section widens to a four-lane divided street. BL I-94 separates from M-63 on the one-way pairing of Ship Street (eastbound) and Port Street (westbound) for three blocks before crossing the St. Joseph River to Benton Harbor; the LMCT concurrency ends at this point.
From there, it follows the five-lane Main Street through downtown Benton Harbor through roundabouts at Riverview Drive and 5th Street. At the latter roundabout, the roadway narrows back to three lanes. The easternmost leg of the loop, from Urbandale Avenue easterly to the roundabout at Crystal Avenue, is a three-lane highway and, from there to the eastern terminus at exit 33 on I-94 and US 31 in Benton Township, is two lanes. At that partial cloverleaf interchange, the roadway defaults onto US 31.
The highway through the downtowns of Benton Harbor and St. Joseph was a part of US 12 when the United States Numbered Highway System was created in late 1926. US 31 was also routed concurrently through the area. The US 33 designation was later added to US 31 from the state line northward to US 12 in St. Joseph in 1937. On November 2, 1960, the I-94/US 12 freeway opened around the Benton Harbor–St. Joseph area, and the former route of US 12 through downtown was renumbered BL I-94. By the next year, US 33 was extended along BL I-94/US 31, and the eastern end of BL I-94 was converted to a divided highway. In 1962, US 31 was rerouted out of downtown Benton Harbor and St. Joseph to follow a new freeway east of Benton Harbor, removing it from BL I-94/US 33. When the business route was first constructed, it had half of a bridgeless diamond interchange each at Crystal and Euclid avenues, with the intent of building overpasses for both crossroads at a later date. Due to a high number of accidents at these two roads, construction began in 1966 to remove the two ramps at Euclid Avenue while also moving that road to an overpass and adding two more ramps at Crystal Avenue. Also as first constructed, the interchanges at each end of the route only consisted of two ramps; a third ramp was added to the eastern end before the highway opened, and the interchange at the western end was converted to a full interchange in 1979.
A new pair of bridges over the St. Joseph River and adjacent Morrison Channel opened in part in 1976 and in full in 1977, replacing bridges built in 1909 and 1911, and were named and dedicated the following month. A planned relocation south of St. Joseph, proposed as late as 1979, was never built. US 33 was truncated in 1986, removing it from BL I-94 and replacing it with M-63 the following year when signage was updated. The Great Lakes Circle Tours were approved by the Michigan Department of Transportation (MDOT) and its counterparts in Minnesota, Ontario, and Wisconsin. In 2016, the section of the business loop concurrent with M-63 was dedicated as part of the West Michigan Pike Pure Michigan Byway.
The interchange at the eastern terminus was rebuilt as part of the completion of the St. Joseph Valley Parkway (US 31 relocation); the reconstruction started in 2020. The former diamond interchange at Crystal Avenue was also replaced with a roundabout in 2020. Parkway construction was completed in November 2022.
Major intersections
Kalamazoo
Business Spur Interstate 94 (BS I-94) is a state trunkline highway that forms a business spur for from near downtown Kalamazoo to the I-94 freeway. The western terminus is on the far-eastern edge of the city, where BS I-94 intersects the western end of M-96. BS I-94 follows Amvets Memorial Parkway, a four-lane expressway to its eastern terminus at I-94's exit 81.
On December 7, 1959, the I-94/US 12 freeway opened on the south side of Kalamazoo. When US 12 was shifted to follow the new freeway, the former route through downtown Kalamazoo was redesignated Business US Highway 12 (Bus. US 12). The next year, it was renumbered Business Loop I-94 (BL I-94). In 1963, the US 131 freeway opened on the west side of Kalamazoo. Along with the creation of Bus. US 131 along a portion of the BL I-94 routing, BL I-94 was rerouted along the US 131 freeway on the west end back to I-94. The section of Stadium Drive west of US 131 and the 9th Street routing was removed from BL I-94. Kalamazoo and the newly built Michikal avenues were transferred to state jurisdiction in 1965. Afterward, Kalamazoo and Michigan avenues were used as a pair of one-way streets downtown. Kalamazoo and Michikal were then signed as westbound BL I-94 from Stadium Drive to Michigan Avenue while Main Street and Michigan Avenue continued to serve eastbound traffic.
The City of Kalamazoo accepted jurisdiction of the trunklines within the city's downtown from MDOT in January 2019; and several highway changes were made as a result. BL I-94 was removed from the US 131 freeway and Stadium Drive, although a section of the latter has been retained by the state as an unsigned highway. The rest of the BL I-94 routing along Stadium Drive, Main Street, Michigan and Kalamazoo avenues, and King Highway was turned over to city control and removed from the state highway system. A short section of King Highway west of the M-96 junction was retained by the state as an unsigned highway, leaving the section of BL I-94 from M-96 east to I-94 as a signed highway, albeit renamed to BS I-94 to reflect the fact that it no longer reconnects to I-94 on both ends.
Major intersections
Battle Creek
Business Loop Interstate 94 (BL I-94) is a state trunkline highway serving as a business loop from I-94 through downtown Battle Creek. The highway begins at exit 92 on I-94 near the Kalamazoo–Calhoun county line. BL I-94 runs concurrently along M-37 northwesterly from the freeway on the two-lane Columbia Avenue on the eastern edge of Fort Custer. At an intersection south of W. K. Kellogg Airport, BL I-94/M-37 turns easterly to run on the southern side of the airport. At the airport's southeaster corner, the business loop intersects M-96 and turns northward, merging onto M-96. BL I-94/M-37/M-96 follows Helmer Road on the eastern edge of the airport to Dickman Road. At Dickman Road, M-37 turns westerly and BL I-94 turns easterly on a road that is four lanes wide with a center turn lane. From there, the business loop follows West Dickman Road along a four-lane divided highway (except between 24th and 20th streets) through a residential area on the northern side of Battle Creek. Dickman Road turns southeasterly as a five-lane undivided highway through downtown Battle Creek, parallel to a curve in the Kalamazoo River near its confluence with the Battle Creek River. BL I-94 skirts the edge of downtown by turning southward and then eastward to cross the Kalamazoo River. On the eastern side of the river, the business loop intersects I-194/M-66. East of the freeway interchange, Dickman Road narrows to three lanes and ends at Main Street. BL I-94 turns northwesterly along Main Street, northeasterly along Hamblin Avenue and then southeasterly on Michigan Avenue on the eastern side of downtown. BL I-94 follows the three-lane Michigan Avenue, narrowing to two lanes east of Porter Street. BL I-94 rejoins M-96 at an intersection with Columbia Avenue in Emmett Township near the Kalamazoo River. BL I-94/M-96 (Michigan Avenue) runs concurrently as a three-lane roadway through Emmett Township. The center turn lane drops southeast of Wattles Road, and the business loop continues to its eastern terminus at exit 104 on I-94.
In late 1940, a southerly bypass of downtown Battle Creek opened. US 12 was rerouted out of downtown to follow Columbia Avenue. The former route was redesignated Business US Highway 12 (Bus. US 12). In 1958 or 1959, a section of the route of Bus. US 12 was split onto a one-way pairing of streets through downtown Battle Creek. On December 7, 1959, the southern I-94/US 12 bypass of Battle Creek was dedicated and opened to traffic. The former routing of US 12 along Columbia Avenue was turned over to local control and the route of Bus. US 12 was extended via Michigan Avenue easterly and M-78 (Capitol Avenue) southerly to connect to the new freeway. Later the next year, this business loop was redesignated BL I-94. When the first segment of I-194 opened in 1961, BL I-94/M-78 was rerouted to follow the freeway. In 1964, the western end of the business loop was realigned to follow Dickman Road west to Fort Custer and south along Skyline Drive to I-94. The next year, as I-194 was completed and M-78 was replaced by an extended M-66, BL I-94 was rerouted through the downtown area. From Dickman Road, BL I-94 followed I-194/M-66 north to the end of the freeway at Hamblin Avenue and turned along Hamblin Avenue to Michigan Avenue via Jay Street. A minor realignment in 1970 shifted the connection between Hamblin and Michigan avenues. The one-way setup through downtown was removed in 1984. M-96 and M-37 were extended in 2000, running concurrently between Skyline Drive and the Helmer Road intersections. M-89 replaced part of M-37 but did not follow the latter's routing to I-194/M-66 near downtown. Then in 2008, BL I-94 was removed from the northern segment of I-194/M-66 freeway and rerouted to follow Dickman Road to Main Street back to Hamblin Avenue.
To expand the blast radius for ammunitions testing at Fort Custer, MDOT rerouted the business loop and M-37 to run along the southern and eastern edges of the airport instead of following roads on the opposite sides. This change was completed in 2015.
Major intersections
Marshall