Interstate 78 in New Jersey

Interstate 78
I-78 highlighted in red
Route information
Maintained by NJDOT, DRJTBC, NJTA, and PANYNJ
Length	67.8 mi[1][2] (109.1 km)
Existed	1958–present
History	Completed in 1989
NHS	Entire route
Restrictions	No hazardous goods east of Marin Boulevard
Major junctions
West end	I-78 at the Pennsylvania state line in Phillipsburg
Major intersections	US 22 / Route 173 in Greenwich Township Route 173 in Bloomsbury Route 31 in Clinton Township I-287 in Bedminster Route 24 / Route 124 in Springfield G.S. Parkway in Union/Hillside US 1-9 / Route 21 in Newark I-95 / N.J. Turnpike / US 1-9 in Newark Route 165 / Route 440 in Jersey City Route 139 in Jersey City
East end	I-78 at the New York state line in Jersey City
Location
Country	United States
State	New Jersey
Counties	Warren, Hunterdon, Somerset, Union, Essex, Hudson
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future New Jersey State Highway Routes Interstate US State Scenic Byways
← Route 77 → Route 79
← Route 10 → Route 12

Interstate 78 (I-78) is an east–west route stretching from Union Township, Lebanon County, Pennsylvania, to New York City. In New Jersey, I-78 is called the Phillipsburg–Newark Expressway and the Newark Bay Extension of the New Jersey Turnpike. The highway runs for 67.8 miles (109.1 km) in the northern part of the state of New Jersey from the I-78 Toll Bridge over the Delaware River at the Pennsylvania state line in Phillipsburg, Warren County, east to the Holland Tunnel under the Hudson River at the New York state line in Jersey City, Hudson County. The Phillipsburg–Newark Expressway portion of I-78, formally called the Lightning Division Memorial Highway, runs from the Phillipsburg area east across rural areas of Western New Jersey before entering suburban areas in Somerset County. The road crosses the Watchung Mountains, widening into a local–express lane configuration at Route 24 as it continues through urban areas to Newark. Here, I-78 intersects the mainline of the New Jersey Turnpike (I-95) and becomes the Newark Bay Extension, crossing the Newark Bay Bridge and continuing to Jersey City. The route, along with Route 139, follows a one-way pair of surface streets to the Holland Tunnel.

In 1927, Route 11 was legislated as a high-speed bypass of US 22 between Whitehouse and Warren but was never built. The earliest parts of I-78 to be built were the Holland Tunnel in 1927 and the Newark Bay Extension. With the creation of the Interstate Highway System in the 1950s, a highway was planned along US 22 through northern New Jersey, becoming I-78 in 1958. The highway between Phillipsburg and Newark was built in various stages from the 1960s to 1989, with the final segment opening at the I-78 Toll Bridge. The section of highway through the Watchung Mountains and across Newark garnered opposition from environmentalists and residents who were worried about the effects of the highway. In addition, there was opposition to building I-78 through Phillipsburg, which resulted in the alignment to the south of the Lehigh Valley. In the 2000s, I-78 was completely rebuilt between Route 24 and the Garden State Parkway. In addition, missing movements between the parkway and I-78 were completed in 2010.^[3]