M-102 is an east–west state trunkline highway in the US state of Michigan that runs along the northern boundary of Detroit following 8 Mile Road. The highway follows the Michigan Baseline, a part of the land survey of the state, and the roadway is also called Base Line Road in places. As a county road or city street, 8 Mile Road extends both east and west of the M-102 designation, which leaves 8 Mile on the eastern end to follow Vernier Road. The western terminus of M-102 is at the junction of 8 Mile Road and M-5 (Grand River Avenue) and the opposite end is at Vernier Road and Interstate 94 (I-94). The 8 Mile Road name extends west to Pontiac Trail near South Lyon with a discontinuous segment located west of US Highway 23 (US 23). The eastern end of 8 Mile Road is in Grosse Pointe Woods, near I-94, with a short, discontinuous segment east of Mack Avenue. The highway was first designated in the late 1920s, connecting US 10 (Woodward Avenue, now M-1) with US 25 (Gratiot Avenue, now M-3). Extensions to the highway designation moved the termini in the 1930s and 1940s east to M-29 (Jefferson Avenue) and US 16 (Grand River Avenue, now M-5). A change in the 1960s added a section of north–south roadway to the eastern end of M-102; that change was reversed within about a year. A western extension along Grand River Avenue in 1977 was reversed in 1994, and M-102 has remained the same since. As the long northern border of the city of Detroit, 8 Mile Road has carried major cultural significance; since the mid-20th century it has served as a physical and cultural dividing line between the wealthier, predominantly white northern suburbs of Detroit and the poorer, predominantly black city. The racial patterns have changed somewhat as middle-class African Americans have also moved north of 8 Mile, but the socioeconomic divide between the city and suburbs remains. Route description Starting at an intersection with Hamburg Road along the Livingston–Washtenaw county line, 8 Mile Road runs eastward to an interchange with US 23 near Whitmore Lake. There is a gap before 8 Mile Road resumes at Pontiac Trail along the Oakland–Washtenaw county line. Near the suburb of Northville, the road curves northward into Oakland County, and Base Line Road follows the county line for about . The road meets I-96/I-275