Construction of I - 675 started in 1969 and the freeway opened in 1971 .
I - 675 is also a state trunkline highway that provided a bypass of the former drawbridge carrying I - 75 and US Highway 23 ( US 23 ) across the Saginaw River .
Construction of state trunkline highway     started in 1969 and the freeway opened in 1971 .
I - 675 is also a state trunkline highway that provided a bypass of the former drawbridge carrying I - 75 and US Highway 23 ( US 23 ) across the Saginaw River .