High Quality Content by WIKIPEDIA articles! Route 181 is a 7.47-mile (12.02 km) state highway in Jefferson Township and Sparta Township in New Jersey, which is in the United States. The highway begins in Jefferson Township at an interchange with New Jersey Route 15 and Weldon Road, where that road changes from a divided surface road to a four-lane freeway. The highway heads through Sparta Township, and indirectly interchanges several times with Route 15. The highway continues through downtown Sparta, where it intersects with several county highways. Route 181 continues north out of Sparta, ending at an intersection with Route 15 at the northern end of the NJ 15 freeway in Sparta Township.