It was later redesignated when it was extended to run concurrently with that city's BL I-94 which was originally part of I-94's predecessor, US 25.

The highway runs northward through farmland south of Coldwater, and after approximately two miles (3.2 km), it enters the city limit at Garfield Road.

North of a crossing of the Battle Creek River, Cochrane Road widens to include a center turn lane.

From that point, BL I-69 follows Lawrence Avenue and then veers northeast onto Lansing Street to complete its loop at exit 61.

[3][15] In 1919, the MSHD[a] signposted the highway system for the first time,[6] and the future US 27 corridor through Charlotte was part of the original M-29.

[7] On November 11, 1926, the United States Numbered Highway System was approved by the AASHO[8][b] and the new US 27 replaced M-29 through Coldwater.

[1] Beginning at exit 93 on I-96/I-69 in Eaton County west of the city, the business loop runs concurrently with M-43 east along Saginaw Highway.

BL I-69/M-43 continues east on Saginaw Highway and crosses into Ingham County at Waverly Road.

From the county line eastward, the highway is known as Saginaw Street, and it passes through residential neighborhoods.

One block separates the two directions of BL I-69/M-43 until the intersection with Martin Luther King Jr. Boulevard near the St. Lawrence Campus of the Sparrow Hospital; east of this intersection two blocks separate the two directions of the highway.

M-43 departs to the southeast via Grand River Avenue while BL I-69 turns northeasterly via the four-lane Saginaw Street.

At an intersection with Haslett Road, Saginaw Street widens into a four-lane divided highway with a grassy median.

Along this section, it resumes the Saginaw Highway name and turns northeasterly again, crossing into Meridian Township.

[7] On November 11, 1926, the United States Numbered Highway System was approved by the AASHO,[8][b] and the new US 27 replaced M-29 and M-14 in the area.

I-69 was routed over I-96 and the new freeway north of Lansing, and the business loop was designated along M-43 and the former Temp.

North of the crossing of the Black River, BL I-69/BL I-94 continues northward on Huron Avenue through downtown.

The business loop continues along Pine Grove Avenue, intersecting the southern end of M-25 at Hancock Street.

It then turns south along the connector to terminate at westbound I-94/I-69 west of the Blue Water Bridge toll plaza.

[36] On November 11, 1926, the United States Numbered Highway System was approved by the AASHO,[8][b] and the new US 25 replaced M-27 in the area.

[32][33] To connect back to I-69, the business route was extended northward along BL I-94 when that highway was designated through downtown in 1986.