Ninth Street will close at U.S. 41 Monday as work along the highway corridor continues.
The closure will last into mid-August, state transportation officials said. They said drivers should use West Mason Street as an alternate.
A sidewalk beneath 41 will remain open to pedestrian traffic.
Crews are nearing the midpoint of a seven-year, $1.055 billion project to being 14 miles of U.S. 41 in Brown County up to interstate highway standards. The major element of the project this year is the creation of an interchange at 41 and Wisconsin 29.