The Michigan Department of Transportation opened all lanes and ramps to northbound and southbound Interstate 75 in Oakland County, northwest of Detroit, 20 days ahead of schedule.

The opening, which occurred just before Labor Day weekend, is part of the $91.8 million project to modernize three miles of I-75 between Coolidge Highway and South Boulevard. The project involved reconstructing the pavement, improvements to the Square Lake Road interchange, realigning sections of the freeway to replace outdated ramps, replacing eight bridges and improving drainage.

Though the lanes are open, work continues on the project. The Adams Road carpool lot is being expanded and permanent freeway markings will be applied. The MDOT says the markings will be done during non-peak driving hours on a to-be-determined weekend.

The freeway was built in 1960 and had not been updated since, the MDOT says. The modernization project will eventually stretch for 18 miles and include the state’s first HOV lane.