The first segment of what later became I-94 within the state , the Willow Run Expressway , was built near Ypsilanti and Belleville in 1941 , with an easterly extension to Detroit in 1945 . This expressway was initially numbered '' 'M -112 ' '' . In the mid-1950s , state and federal officials planned an Interstate to replace the original route of U.S. Highway 12 ( US 12 ) . By 1960 , the length of I-94 was completed from Detroit to New Buffalo . Two years later , the US 12 designation was dropped from the freeway . Subsequent extensions in the 1960s completed most of the rest of the route , including the remaining sections between Detroit and Port Huron which superseded the routing of US 25 . The last segment opened to the public in 1972 when Indiana completed its connection across the state line . Since completion , I-94 has remained relatively unchanged ; a few interchanges have been rebuilt , a second span was constructed for the Blue Water Bridge , and in 1987 , a plane crashed on the freeway during takeoff from the airport in Detroit . The routing of I-94 is notable for containing the first full freeway-to-freeway interchange in the United States , connecting to the Lodge Freeway ( M-10 ) , and for comprising the first complete border-to-border toll-free freeway in a state in the United States . The highway has one auxiliary route , I-194 , which serves downtown Battle Creek , and eight business routes . Various segments have been dedicated to multiple people and places
a plane crashed
Northwest Airlines Flight 255
Interstate 94 in Michigan