U.S. Federal Route 18 runs east-west across Jefferson County. Thism runs south of Interstate 94 in Central Jefferson County. U.S. Rt. 18 passes through the following towns in Jefferson County. Sullivan
Helenville
Jefferson
Cambridge U.S. Rt. 18 is multi-plexed in Jefferson County. Wisconsin State Route 89, near Jefferson. U.S. Rt. 18 intersects the following highways in Jefferson County. Wisconsin State Route 26, at Jefferson. Wisconsin State Route 89, near Jefferson. Wisconsin State Route 89, near Jefferson.
WB U.S. Rt. 18 in Sullivan. WB U.S. Rt. 18 west of Sullivan. WB U.S. Rt. 18 west of Helenville. WB U.S. Rt. 18 east of Jefferson.