Route 15 is a state highway in New Jersey, spanning Morris and Sussex counties, which travels for 19 miles (31 km) from U.S. Route 46 in Dover to an intersection with U.S. Route 206 in Frankford Township. It becomes a divided highway in Wharton Borough until becoming a freeway bypass near Sparta. Route 15 was originally Route 6A from 1927 until 1953, when a renumbering occurred and the route was given its current number. Since the finishing of the Sparta Bypass, the New Jersey Department of Transportation (NJDOT) and North Jersey Transportation Planning Authority have considered more bypasses and alignment changes for Route 15.

U.S. Route 46 (US 46) is an east–west U.S. Highway completely within the state of New Jersey, running for 75.34 mi (121.25 km), making it the shortest signed, non-spur U.S. Highway. The west end is at an interchange with Interstate 80 (I-80) and Route 94 in Columbia, Warren County, on the Delaware River. The east end is in the middle of the George Washington Bridge over the Hudson River in Fort Lee, Bergen County, while the route is concurrent with I-95 and US 1-9. Throughout much of its length, US 46 is closely paralleled by I-80. US 46 is a major local and suburban route, with some sections built to or near freeway standards and many other sections arterials with jughandles. The route runs through several communities in the northern part of New Jersey, including Hackettstown, Netcong, Dover, Parsippany-Troy Hills, Wayne, Clifton, Ridgefield Park, Palisades Park, and Fort Lee. It crosses over the Upper Passaic River at several points. The road has been ceremonially named the United Spanish–American War Veterans Memorial Highway.