By the 1950s, the plan to build NJ 3 in both directions out of Paterson had been abandoned. A new road, NJ S-3, was carrying traffic from NJ 6 on the west end of Clifton to NJ 3 in East Rutherford; the connection from NJ 23 to NJ 6 to NJ S-3 was deemed sufficient to bring traffic from northern Passaic County to the Lincoln Tunnel. In 1953, NJ S-3 was renamed NJ 3, and the already-built portions of NJ 3 in both East Rutherford and Paterson became NJ 20.
A third road also bore the NJ 20 designation for a number of years. A spur off the Garden State Parkway was planned to reach the Passaic River just downstream from the Great Falls and encircle Paterson, hooking into the existing NJ 20. The connection was never built, and in 1985 the spur was renamed NJ 19.
| Mile | Street Name | Feature (West to East) |
| 0.00 | NJ 20 BEGINS, Clifton City | |
| 0.00 | NJ 20 | US 46 {merge} |
| 0.08 | NJ 20 | Crooks Ave, CR 630 {overpass} |
| 0.08 | Entering Paterson City | |
| 0.20 | NJ 20 | US 46 westbound {overpass} |
| 0.57 | NJ 20 | I-80 interchange ramp {overpass} |
| 0.70 | NJ 20 | Bergen-Passaic Expwy, I-80 {underpass} |
| 0.81 | NJ 20 | I-80 interchange ramp {underpass} |
| 0.85 | McLean Blvd | Susquehanna Railroad {underpass} |
| 1.27 | McLean Blvd | U-turn ramp, northbound to southbound {signal} |
| 1.68 | McLean Blvd | NJ 20 north to NJ 4 east ramp {underpass}, southbound only |
| 1.86 | McLean Blvd | Broadway, NJ 4 {underpass} |
| 1.92 | McLean Blvd | (Edward St, ramp to/from NJ 4 westbound) {signal} |
| 2.57 | McLean Blvd | U-turn ramp, southbound to northbound {signal} |
| 2.63 | McLean Blvd | East 33 St, CR 651 {signal} |
| 2.68 | McLean Blvd | (10 Ave, CR 651) {signal} |
| 3.24 | McLean Blvd | 5 Ave connector {signal} |
| 3.35 | McLean Blvd | (5 Ave, CR 652) {signal} |
| 3.45 | McLean Blvd | [Fair Lawn Ave, Bergen CR 76] {signal} |
| 3.49 | McLean Blvd | 4 Ave {signal} |
| 3.82 | Highway splits; southbound uses 2 Ave, northbound uses 1 Ave | |
| 3.82 | End NJDOT maintenance; begin Passaic Co. maintenance (southbound only) | |
| 3.97 | McLean Blvd | [Maple Ave, bridge to Bergen CR 69 | 507], northbound only |
| 3.97 | End NJDOT maintenance; begin Passaic Co. maintenance (northbound only) | |
| 4.09 | 1 Ave | 2 Ave | Madison Ave, CR 649 {signal, southbound only} |
| 4.15 | 1 Ave | 2 Ave | Lincoln Ave, CR 504 | CR 653 |
| 4.15 | NJ 20 ENDS, Paterson City | |