DULUTH, MN (KDAL) - The Minnesota Department of Transportation (MnDOT) says the northbound exit ramp from I-35 to Superior Street will be temporarily closing on Thursday at 9 a-m until Friday at 5 a-m. Motorists heading to downtown Duluth from that exit will need to take the exit ramp at 5th Avenue West. The closure is part of bridge work in the area. That project has already closed the Mesaba Avenue (Highway 194) exit from northbound I-35 with a marked detour using Highway 53 to access Centr...