The current alignment of US 1/9 south of Elizabeth was planned as pre-1927 Route 1 in 1916; this road was extended to the Holland Tunnel in Jersey City in 1922. When the U.S. Highway System was created in 1926, US 1 and US 9 were marked concurrent through northern New Jersey between Rahway on the current alignments of Route 27 and US 1/9 Truck. In 1927, pre-1927 Route 1 became Route 25, and Route 1 and Route 6 were legislated along the current US 1/9 north of Jersey City. US 1/9 originally went to the Holland Tunnel on Route 25; after the George Washington Bridge opened the two routes were realigned to their current routing north of Jersey City. After the Pulaski Skyway opened in 1932, US 1/9 and Route 25 were routed to use this road, which soon had a truck ban resulting in the creation of Route 25T (now US 1/9 Truck). South of Newark, US 1/9 was moved from Route 27 to Route 25. In 1953, the state highways running concurrent with US 1/9 in New Jersey were removed. In 1964, the approaches to the George Washington Bridge were upgraded into I-95.