Route 42 is a state highway in the U.S. state of New Jersey within the Camden area. It runs 14.28 mi (22.98 km) from an intersection with U.S. Route 322 and County Route 536 Spur in Monroe Township, Gloucester County to an intersection with Interstate 76 and Interstate 295 in Bellmawr, Camden County. The route is a mix of freeway and divided four-lane arterial road. The southern portion of Route 42 is a local arterial route and one of several highways comprising the Black Horse Pike, a road that runs from Camden to Atlantic City. The northern portion is a six- to eight-lane freeway referred to locally as the North–South Freeway (or simply the 42 Freeway) that is directly connected to the Atlantic City Expressway. Major intersections along the route include the Atlantic City Expressway and the southern terminus of Route 168 in Turnersville, another intersection with Route 168 in Blackwood, and Route 41 and Route 55 in Deptford Township.
Route 42 was originally designated in 1927 to run along the Black Horse Pike between Ferry Avenue in Camden and the present U.S. Route 40/U.S. Route 322 split in the McKee City section of Hamilton Township, Atlantic County. In 1953, the southern terminus was cut back to its current terminus in the Williamstown section of Monroe Township to avoid the concurrency it shared with U.S. Route 322. After the completion of the North–South Freeway between Bellmawr and Turnersville in 1959, Route 42 was moved to this freeway, and the Black Horse Pike north of Turnersville became Route 168.
The freeway portion of Route 42 has been improved many times. Construction work has commenced on a project known as the "I-295/I-76/Route 42 Direct Connection," which is reconstructing the dangerous and congested Route 42/Interstate 295/Interstate 76 interchange in Bellmawr.
Route 42 begins at an intersection with U.S. Route 322 and County Route 536 Spur in Monroe Township, Gloucester County where it heads to the north on the Black Horse Pike. For the first portion of the route, Route 42 is a divided four–lane arterial highway that intersects various local roads. Some intersections along this section feature jughandles. There are also many businesses lining the highway. The route crosses County Route 689 (Berlin-Cross Keys Road) and enters Washington Township. It then intersects the northern terminus of County Route 555 (Tuckahoe Road). After the intersection with County Route 555, Route 42 intersects three more county routes: County Route 655 (Fries Mill Road), County Route 639 (Ganttown Road), and County Route 651 (Greentree Road). The Atlantic City Expressway then starts to the right at an unnumbered intersection, Route 168 continues to the north on the Black Horse Pike, and Route 42 becomes the six–lane North–South Freeway.