In 1962, a section of freeway along US 31 was opened between I-94 and the Berrien–Van Buren county line. This section was originally designated as part of I-96/US 31; the former route near the lakeshore became just US 33. The MSHD petitioned federal highway officials to switch the Interstate designations west of Grand Rapids, reversing the I-96 and I-196 numbers to their current configurations. After the designation switch was approved in 1963, an additional was opened from the northern end of the freeway near Benton Harbor to Holland as I-196/US 31. The freeway was also extended northward from Muskegon to the Muskegon–Oceana county line north of Montague in 1963.