M-39 is a 16-mile-long (26 km) north–south state trunkline highway in Metro Detroit area of the US state of Michigan that runs from Lincoln Park, on the south end, to Southfield on the north. The official southern terminus of M-39 is at the corner of Southfield Road and Lafayette Boulevard in Lincoln Park, one block southeast of the junction of Interstate 75 (I-75, Fisher Freeway) and two blocks northwest of M-85 (Fort Street). From there the highway heads northward. The first 2.3 miles (3.7 km) of the highway follows Southfield Road, a divided highway in the Downriver area. It then transitions into the Southfield Freeway, which is a 13.7-mile-long (22.0 km) freeway that runs from Allen Park north through Dearborn, and then the west side of Detroit, to Southfield. The northern terminus is