Starting at the I-74/US 51 interchange, US 51 Business traveled northward via Main Street towards downtown Bloomington.

Continuing north, the route splits even further out near the McLean County Courthouse and Square.

Eventually, south of Locust Street, the one-way pair comes closer together but not completely.

After crossing under the overpass, the southbound route then moves slightly outward (following Kingsley Street).

In the Illinois State University, the southbound and the northbound route come together at Main Street/College Avenue.