At least 12 special routes of U.S. Route 16 have existed, including four in Michigan.
Special routes of U.S. Route 16 Wikipedia
U.S. Route 16 Business (US 16 Business) in Newcastle, Wyoming is mainline US 16 signed as a Business Route. It includes West Main Street east of U.S. Route 16 Truck (Newcastle, Wyoming), and South Summit Street east of West Main Street and North Summit Street.
U.S. Route 16 Truck (US 16 Truck) in Newcastle, Wyoming runs south of mainline US 16. It begins at West Main Street between Quarter Horse Drive and Sixth Avenue, directly across from Seventh Avenue, and Divide Avenue and South Summit Street.
U.S. Route 16 Truck (US 16 Truck) in Hill City, South Dakota runs east of mainline US 16/US 385 along Walnut Avenue, and is also overlapped with US 385 Truck. It begins at Main Street north of Pond Court, then runs along side the Mickelson Trail. Across the street from MacGregor Street the street name changes to Railroad Avenue for the South Dakota State Railroad Museum and the former Chicago, Burlington and Quincy Railroad depot, which serves the Black Hills Central Railroad. The name Walnut Avenue is revived as "North Walnut Avenue" as US Truck Route 16/385 ends at East Main Street.