Interstate 78

Interstate 78 (I-78) is an Interstate Highway in the Northeast United States, running 144 miles (231 km) from Interstate 81 northeast of Harrisburg, Pennsylvania, through Allentown, Pennsylvania, and western and northern New Jersey to the Holland Tunnel and Lower Manhattan in New York City.

I-78 is a major road linking ports in the New York City and New Jersey area to points west, and sees over 4 million trucks annually, with trucks representing 24% of all traffic. Truck traffic on the road is projected to rise once the widening of the Panama Canal is completed in 2015, when more Asian ships are expected to use East Coast ports.

Route description

Pennsylvania

I-78 begins at a directional-T interchange with I-81 in Union Township, Lebanon County, Pennsylvania, about 25 miles (40 km) northeast of Harrisburg. Near the east end of the county, at exit 8, U.S. Route 22 (US 22) merges with I-78, running concurrently for the next 43 miles (69 km).

At exit 51, in Upper Macungie Township, US 22 leaves the highway. Passengers traveling on I-78 eastbound must use this exit to access I-476 (Northeast Extension of the Pennsylvania Turnpike), and westbound travelers must use exit 53 (northbound Pennsylvania Route 309 (PA 309)) and then westbound US 22. From exits 53 to 60, I-78 runs concurrently with PA 309. The six-lane overlap bypasses the City of Allentown to the south and crosses South Mountain.

Interstate 78 in New Jersey

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 67.83 miles (109.16 km) in the northern part of the state of New Jersey from the Interstate 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.

Interstate 78 in New York

Interstate 78 (I-78) is a part of the Interstate Highway System that runs from Union Township, Lebanon County, Pennsylvania, to New York City. The portion of I-78 within the U.S. state of New York is just 0.90 miles (1.45 km) long as it crosses the Hudson River from New Jersey via the Holland Tunnel and ends at the exit rotary in Lower Manhattan. Therefore the entire route is maintained by the Port Authority of New York and New Jersey. However, a much longer route was once planned, heading east via the Williamsburg Bridge to the John F. Kennedy International Airport and then north over the Throgs Neck Bridge to I-95 in the Bronx. The parts of this that were built are now New York State Route 878 (NY 878) and I-295.

Route description

The Holland Tunnel consists of two one-way two-lane tunnels. The entrance plaza to the westbound tunnel is a rectangular block bounded by Broome, Varick, Watts, and Hudson streets, with four entrances feeding into the tunnel from all directions, including one from Canal Street. The westbound portal is to the north, just south of Dominick Street. The exit plaza is in the square double block that previously housed the New York Central Railroad's St. John's Park Terminal, bounded by Laight, Varick, Beach, and Hudson streets. Traffic leaves the tunnel at a portal at the southeast corner of Canal and Hudson streets, and heads southeast along the south line of Canal Street and south along the west line of Varick Street to the northeast corner of the plaza. Five exits, numbered 1 to 5, can be taken from the almost-circular roadway known as the Holland Tunnel Rotary one to each corner and one to the middle of the east side (Varick Street). A pedestrian overpass crosses the entrance to the plaza and exit 5 at the northeast corner, since the entrance from the tunnel cuts Laight Street.