It is a four- to six-lane divided highway for most of its length that runs through residential and commercial areas of Paterson, intersecting with Interstate 80 and Route 4 at interchanges.

[1] The route runs in between the Passaic River to the east and two large cemeteries to the west before coming to an interchange with Interstate 80 and Market Street.

Past Interstate 80, Route 20 becomes a six-lane arterial road that heads under New York, Susquehanna and Western Railway's New Jersey Subdivision line and through a mix of residential and commercial areas.

Past this intersection, the route proceeds through urban areas, turning west and splitting into a one-way pair.

[6] A new highway was to be built connecting the two, bypassing the Paterson Plank Road to the north.

[7] By this point, the Paterson Plank Road was no longer in the state highway system.