The expansion of the highway system followed the opening of the
George Washington Bridge. In the
1927 New Jersey state highway renumbering Route 6 was assigned to the route across northern New Jersey, using the old Route 5 from Delaware to Netcong, Route 12 from Hackettstown to Paterson, and a generally new alignment parallel to
Route 10 from Paterson to the proposed
George Washington Bridge. In
Paterson, Route 6 was marked along city streets including McBride Avenue, Spruce Street and Market Street. In 1929, Route 6 was redefined to use none of the old road east of Paterson (it had formerly been planned to use Market Street west of roughly where
Route 17 now crosses it), and Route 5 was cut back to run only east from
Ridgefield. Route 6 was redefined to bypass Paterson to the south. The new highway would enter Paterson just south of Market Street, but then turn south and southwest before heading west to rejoin the route at the Little Falls bypass at the Union Boulevard crossing. The old road along Union Boulevard towards Paterson was assigned
Route S6, as a spur of Route 6. By 1937, most of Route 6 had been completed with the exception of the Paterson bypass. A realignment at the Passaic River crossing near
Pine Brook was built in the 1940s, along with a new road for a short distance west from Pine Brook. The Route 6 designation was dropped in favor of US 46 in the 1953 renumbering. ==Bridges==