New Jersey Route 21

in Downtown NewarkRoute 21 heads north from the Newark Airport Interchange with US 1/9 in Newark near Newark Airport on a six-lane freeway known as McCarter Highway. This portion of Route 21 serves to connect Newark Liberty with downtown Newark. The route interchanges with I-78 and US 22 and then crosses over Conrail Shared Assets Operations' Greenville Running Track, Lehigh Line, and Passaic and Harsimus Line and then Amtrak's Northeast Corridor rail line on a viaduct, coming to an interchange with Broad Street that provides access to Frelinghuysen Avenue (Route 27). The route continues north, paralleling the elevated Northeast Corridor tracks that lead up to Newark Penn Station, which serves Amtrak and NJ Transit trains and PATH's Newark–World Trade Center line. At the intersection with Emmet Street, Route 21 becomes a four-lane surface road and intersects with Murray Street, which provides access to the Ironbound neighborhood of Newark. This section of Route 21 through the southern part of Newark has a high accident rate due to the heavy concentration of businesses and traffic lights along this portion of road. The road widens to six lanes and the route intersects with Market Street (CR 510) near Newark Penn Station and continues north into Downtown Newark, splitting from the Northeast Corridor rail line. It crosses the intersection with Raymond Boulevard and the route meets the intersection with Center Street (CR 508), which it forms a concurrency. Route 21 and CR 508 head along the west bank of the Passaic River, passing by the New Jersey Performing Arts Center. CR 508 splits from Route 21 by heading east on Bridge Street, crossing the Passaic River, and Route 21 continues north, passing by the former site of Bears & Eagles Riverfront Stadium. After passing under NJ Transit's Montclair-Boonton Line/Morris & Essex Lines and interchanging with I-280, the route intersects with Clay Street (CR 506 Spur). Past the intersection with 3rd Avenue, Route 21 becomes a six-lane freeway again. After about a quarter mile, the northbound side swings under the southbound side and the freeway becomes double-decker, passes by Mt. Pleasant Cemetery, and returns to single-decker configuration. It then interchanges with Chester Avenue and Riverside Avenue with a southbound exit and northbound entrance before passing over Norfolk Southern Railway's Newark Industrial Track line. Route 21 comes to a northbound exit and southbound entrance for Grafton Avenue and Mill Street; this interchange actually connects with the original McCarter Highway, a street that retains this name and acts as a service road to Route 21 for a few blocks in this area, near several industries. Route 21 briefly becomes a double-decker freeway again past the latter interchange and passes under Norfolk Southern Railway's Boonton Line, before crossing into Belleville at the Second River crossing. The freeway features a southbound exit for Mill Street and a northbound exit for Rutgers Street/Belleville Turnpike (Route 7 and CR 506) as it passes by houses on the left side of the freeway. Route 21 features an interchange with Main Street that has a southbound exit and an entrance in both directions. It enters Nutley where the freeway interchanges with County Route 646 (Park Avenue), continuing north through residential areas along the Passaic River. As Route 21 crosses into Clifton, Passaic County, it passes under NJ Transit's Main Line and comes to an interchange with Route 3. North of this point, the freeway comes to a northbound exit and southbound entrance for southbound River Road (CR 624), passing through residential neighborhoods, and enters Passaic. In Passaic, Route 21 interchanges with Brook Avenue (CR 608), Van Houten Avenue (CR 614), and River Drive (CR 624). The route features an interchange with River Drive (CR 624) and Main Avenue (CR 601) and meets State Street at a partial interchange with a northbound exit and southbound entrance. This interchange provides access to the Union Avenue Bridge over the Passaic. Route 21 heads farther to the west of the Passaic River, passing through industrial and residential areas of Passaic. The freeway briefly enters Wallington and comes to an interchange that provides access to Market Street (CR 619), Dayton Avenue, and Monroe Street. Route 21 continues to the north and resumes along the west bank of the Passaic River, narrowing to four lanes and crossing back into Clifton. Upon entering Clifton, the route comes to an interchange with Ackerman Avenue. The freeway heads to the northwest, passing by a park and featuring a southbound exit and northbound entrance for Lexington Avenue before ending at an interchange with US 46. ==History==

Route 21 history starts in 1927 with the New Jersey highway renumbering plan. The surface portion of Route 21 in Newark, which follows the Northeast Corridor rail line, was commissioned in 1934 between Routes 25 and 29 and Market Street and the portion through downtown Newark was commissioned in 1936 between Market Street and Clay Street. Route 19 was designated in 1939 from Paterson to Belleville. In 1948, the Route 21 designation was extended north to Paterson, replacing Route 19 (which has since been reassigned elsewhere). By Joint Resolution No. 4, approved March 22, 1934, the New Jersey Legislature designated Route 21 as the McCarter Highway, in memory of Newark financier and philanthropist Uzal Haggerty McCarter. Freeway Plans for a freeway along the Route 21 corridor between Newark and Paterson date back to the early 1930s and became official in 1951. In 1958, the highway was extended northward as a freeway along the west bank of the Passaic River to an interchange with Park Avenue in Nutley. Route 21 was extended to the Passaic Park interchange in 1962, Main Avenue in 1968, and Monroe Street in 1973. 1970s legislation stopped the further extension northward until environmental impact could be assessed, leaving a two-mile city street portion in place to connect to Routes 20, 46, and I-80 in Paterson for over 25 years. According to the original freeway plans, the portion north of Monroe Street was to cross over the Passaic River and terminated in Elmwood Park at the interchange of I-80 and CR 507. This routing would have allowed the highway continue with six full lanes. However, the proposal was opposed by residents who lived on the east side of the Passaic River, and for a quarter-century, traffic headed for Paterson had to use local streets in Passaic. In the 1980s, plans were resurrected for completing the Route 21 freeway along the west bank of the Passaic River to US 46 in Clifton, avoiding the earlier objections. Official plans were made in 1996, and in late 1997, construction began on this portion of the freeway. It opened on December 20, 2000, at a cost of $136 million. However, this new route was limited mostly to four lanes (three lanes at the very northern end), utilizing the right of way of the Dundee Canal. A wider highway would have encroached on private property or the Passaic River, entailing much greater costs. Newark section improvements Sections of Route 21 through Newark were improved in the 1990s and the 2000s. The four-lane viaduct over the Northeast Corridor, which was built in the 1920s, was replaced between 1997 and 2003 at a cost of $253 million. A major reconstruction occurred at the interchange with I-280 at the William A. Stickel Memorial Bridge in Newark from 2015 to 2018. On April 27, 2018, the portion of Route 21 between mileposts 3.90 and 5.83 was dedicated the "Roberto Clemente Memorial Highway" after the late baseball legend Roberto Clemente, who wore number 21 for his entire career with the Pittsburgh Pirates. ==Major intersections==