Interstate 96 (I-96) is an east–west Interstate Highway that runs for approximately 192 miles (309 km) entirely within the US state of Michigan from the Muskegon area to Detroit. The highway passes through the Grand Rapids and Lansing areas. The first segments were opened as relocations of its predecessor, U.S. Highway 16 in the late 1950s. Most of the highway was completed by 1962. The four auxiliary Interstates were collectively constructed in the 1960s and 1970s, with the last completed in the late 1980s. There are also two current and four former business routes associated with I-96; these follow segments of highway formerly used by I-96's predecessor.