Business Loop I-69 - Port Huron

I-69 and I-94 converge to the west of Port Huron at a directional T interchange. The exchange ties into a wye interchange with an expressway spurring southeast to the couplet of Griswold Street west and Oak Street east into the city. Designated as Business Loop I-69, the couplet leads east to Business Loop I-94 (Military Street) near the St. Clair Riverfront.

The two business routes combine northward along old U.S. 25 to Downtown. Following Huron and Pine Grove Avenues, the pair tie into I-69/94 at the south end of M-25 and west approach to the Bluewater Bridge linking Port Huron with Point Edward, Ontario.

When the freeway along M-21 was completed in 1984, it was designated as an extension of I-69 east from Flint to Port Huron. The former trunk highway east from Port Huron Township to M-25 (Military Street) was subsequently redesignated as Business Spur I-69.

Additional changes were made by 1987, when M-25 south from the Bluewater Bridge approach was redesignated as Business Loop I-94. This coincided with the change of Business Spur I-69 to a 6.11 mile long loop running in tandem with BL I-94 northward (Bessert, 2026).