Interstate 78

Interstate 78 marker

Interstate 78

Map
I-78 highlighted in red
Route information
Maintained by PennDOT, DRJTBC, NJDOT, NJTA, and PANYNJ
Length146.28 mi[1] (235.41 km)
Existed1957–present
NHSEntire route
RestrictionsNo hazardous goods east of Marin Boulevard
Major junctions
West end I-81 in Union Township, PA
Major intersections
East endCanal Street in New York, NY
Location
CountryUnited States
StatesPennsylvania, New Jersey, New York
Highway system

Interstate 78 (I-78) is an east–west Interstate Highway in the Northeastern United States that runs 144 miles (232 km) from I-81 northeast of Harrisburg, Pennsylvania through Allentown to western and North Jersey, terminating at the Holland Tunnel entrance to Lower Manhattan in New York City. Major metropolitan areas along I-78 route include the Lehigh Valley in Pennsylvania, the Gateway Region in New Jersey, and the New York metropolitan area.

I-78 links ports in New York City and North Jersey to points west, including the Lehigh Valley, the third-largest metropolitan region of Pennsylvania. I-78 accommodates over four million trucks annually, representing 24 percent of all truck traffic in the nation.[2] It also is a major connection point to the New York metropolitan area's three major international airports, Newark Liberty International Airport, John F. Kennedy International Airport, and LaGuardia Airport.

Route description[edit]

Lengths
  mi[1] km
PA 77.95 125.45
NJ 67.83 109.16
NY 0.50 0.80
Total 146.28 235.41

Pennsylvania[edit]

The I-78 interchange approaching I-81 north in Union Township, Pennsylvania
I-78 westbound past the PA 412 interchange in Bethlehem in the Lehigh Valley

I-78 begins at a directional T interchange with I-81 in Union Township, 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, and runs concurrently for the next 43 miles (69 km) through Berks and Lehigh counties.[3]

At exit 51, in Upper Macungie Township, US 22 leaves the highway. Drivers on I-78 eastbound must use this exit to access I-476, also known as the 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.[4][5]

At exit 60 (A–B going westbound), PA 309 yields south to Quakertown.[6] Approximately six miles (9.7 km) east, there is an interchange between PA 412 and I-78 in Hellertown, serving Bethlehem and Lehigh University. At exit 71, PA 33 reaches its southern terminus at a trumpet interchange. PA 33 traverses the Pocono Mountains as it enters Bangor and crosses I-80. The final exit on I-78 in Pennsylvania is Morgan Hill Road, which accesses PA 611 and Easton. I-78 then crosses the I-78 Toll Bridge and enters New Jersey.

New Jersey[edit]

I-78 westbound in Warren Township, New Jersey
I-78 eastbound crossing Newark Bay at Newark Bay Bridge

After the I-78 Toll Bridge, I-78 enters New Jersey as the Phillipsburg–Newark Expressway.[7] The road begins by running parallel with County Route 642 (CR 642) in the town of Alpha. At 3.94 miles (6.34 km), a partial cloverleaf interchange brings together US 22, Route 122, and Route 173 with I-78 in Phillipsburg.[8] US 22 now runs concurrently with I-78 for the next 15 miles (24 km). Going westbound, exit 4 leaves to the right for CR 637 and Warren Glen. The next exit, exit 6, is for CR 632 in Bloomsbury. The route number is not signed on I-78. Exit 7 in Bloomsbury is the first of several eastbound exits for Route 173, which runs parallel the Interstate. Four miles (6.4 km) later, exit 11 leaves to the right as another exit for Route 173. CR 614 is located off the exit. Exit 12 westbound is for Route 173 again. Exit 12 eastbound is for a frontage road paralleling I-78.

Exit 13 is only westbound and is another exit for Route 173. Nearby the exit, going eastbound, the frontage road merges in.[8] Exit 15 is for Route 173 and CR 513 in Franklin Township. Exit 17 is for Route 31 in Clinton Township. In Annandale, US 22 leaves I-78 at exit 18. US 22 continues to Bound Brook and Union County. At exit 20, CR 639 intersects. CR 639 heads to the Round Valley Reservoir. Exit 24 is for CR 523 to Oldwick. At exit 29, I-287, US 202, and US 206 interchange with I-78 in Bedminster. At this point, in Somerset County, exits 33, 36, and 40 are for county routes in Warren Township. At exit 41, I-78 enters Union County[8] and then passes through the Watchung Reservation, where land bridges cross over the highway to allow for the safe passage of wildlife. At exit 45, CR 527 intersects after paralleling for some time. West of exit 48, I-78 splits into express and local highways. Exit 48 is for Route 24 in Springfield Township. Exit 49A is for one of Route 24's spur routes, Route 124. Exit 52 is for the Garden State Parkway in Union Township. At exits 57 and 58, Route 21, US 1, US 9, and US 22 intersect I-78. The exit provides access to Newark Liberty International Airport.

East of exit 58 at the eastern tip of Newark, I-78 becomes the Newark Bay Extension of the New Jersey Turnpike. Past the first toll plaza, I-78 has an interchange with I-95 (New Jersey Turnpike) and crosses Newark Bay via the Newark Bay Bridge.[8] The first exit, 14A, is for Route 440 in Bayonne. Liberty State Park can be reached by taking exit 14B. Exit 14C is the final numbered exit, providing access to the Liberty Science Center. Route 139 runs concurrently with I-78 along a one-way pair of surface streets as it approaches the Holland Tunnel and enters New York state.

New York[edit]

I-78 leaving Jersey City and entering the Holland Tunnel to SoHo and New York City

I-78's length in New York is 0.5 miles (0.80 km)—half of the Holland Tunnel and the egress-only roundabout immediately beyond the end of the tunnel. The route was planned to run east and north through New York City to end at I-95 in the Bronx, but sections of the planned route, including the Lower Manhattan Expressway, were canceled.

In New York City, I-78 continues through the egress-only roundabout known as the Saint John's Rotary. The five separate exits from the Rotary are assigned numbers, exits 1 to 5, in counterclockwise order. Exit 5, the last eastbound exit, leads onto Canal Street. Under original plans, I-78 was to cross Manhattan as the Lower Manhattan Expressway onto the Williamsburg Bridge and then beyond I-278 on Bushwick Expressway through Brooklyn into Queens near the John F. Kennedy International Airport. A section of I-78 at the airport was built as the Nassau Expressway, later I-878 and now New York State Route 878 (NY 878), though most of the westbound side was never built. Under the plans, east of the airport, I-78 would have turned north on the Clearview Expressway, built north of Hillside Avenue in Queens and now I-295, run across the Throgs Neck Bridge, and forked into two spurs, ending at I-95 via the Throgs Neck Expressway, which is now I-695 and the Bruckner Interchange via the Cross Bronx Expressway, which is now part of I-295.[9]

Junction list[edit]

Aerial photo of I-78 in New Jersey and New York City
Pennsylvania
I-81 west-northwest of Jonestown
US 22 east-northeast of Fredericksburg. The highways travel concurrently to east-northeast of Fogelsville.
US 222 west of Allentown
PA 33 southwest of Easton
New Jersey
US 22 east-northeast of Alpha. The highways travel concurrently to Annandale.
I-287 in Bedminster
Route 24 in Springfield
G.S. Parkway in Union Township
US 1 / US 9 / US 22 in Newark
I-95 / N.J. Turnpike in Newark
New York
Canal Street in Lower Manhattan

[10]

Auxiliary routes[edit]

All of I-78's auxiliary routes serve New York City; however, none of these routes actually intersect I-78, following the route's truncation at the eastern end of the Holland Tunnel.

In the Lehigh Valley region of eastern Pennsylvania, PA 378, which exits in downtown Bethlehem was once I-378 but was predesignated as a state route after I-78 was rerouted to a new southerly alignment. I-178 was initially planned to extend in Center City Allentown, but local opposition to the plan led to it being cancelled.

References[edit]

  1. ^ a b Federal Highway Administration (December 31, 2021). "Table 1 - Main Routes". FHWA Route Log and Finder List. Retrieved May 29, 2022.
  2. ^ "New Jersey's Infrastructure for Business | Choose New Jersey". Choose New Jersey, Inc. Retrieved May 29, 2022.
  3. ^ Google (August 31, 2007). "Overview Map of I-78 in Lebanon, Berks, and Lehigh Counties" (Map). Google Maps. Google. Retrieved August 31, 2007.
  4. ^ Google (August 31, 2007). "Overview Map of I-78 Southeast of Allentown" (Map). Google Maps. Google. Retrieved August 31, 2007.
  5. ^ Google (August 31, 2007). "Overview Satellite Image of I-78 with Six Lanes" (Map). Google Maps. Google. Retrieved August 31, 2007.
  6. ^ Google (August 31, 2007). "Interstate 78 in Pennsylvania" (Map). Google Maps. Google. Retrieved August 31, 2007.
  7. ^ New Jersey Department of Transportation. "Interstate 78 Straight Line Diagram" (PDF). Retrieved March 19, 2020.
  8. ^ a b c d Google (August 31, 2007). "I-78, New Jersey, United States" (Map). Google Maps. Google. Retrieved August 31, 2007.
  9. ^ "NYSDOT - Traffic Count Information". Archived from the original on April 28, 2006. Retrieved December 27, 2005.
  10. ^ Rand McNally (2014). The Road Atlas (Walmart ed.). Chicago: Rand McNally. pp. 66, 72, 89. ISBN 978-0-528-00771-2.
  11. ^ a b c d Adderly, Kevin (December 31, 2016). "Table 2: Auxiliary Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of December 31, 2016". Route Log and Finder List. Federal Highway Administration. Retrieved September 24, 2017.
  12. ^ Union County Sheet 1 (Map). New Jersey Department of Transportation. 1967. Retrieved February 13, 2010.
    • Union County Sheet 2 (Map). New Jersey Department of Transportation. 1967. Retrieved February 13, 2010.
  13. ^ a b "Expressway Plans". Regional Plan News (73–74). Regional Plan Association: 1–18. May 1964. Retrieved February 27, 2017 – via Archive.org.
  14. ^ a b Map of Metropolitan New York (Map). Cartography by H.M. Gousha. Chevron Oil Company. 1969.
  15. ^ a b Map of New Jersey (Map). Cartography by General Drafting. Esso. 1970.
  16. ^ West Side Hwy Project, New York: Environmental Impact Statement. West Side Hwy Project, New York: Environmental Impact Statement. New York State Department of Transportation; Federal Highway Administration, United States Department of Transportation. 1977. Retrieved March 19, 2018.
  17. ^ Roberts, Sam (October 7, 1985). "THE LEGACY OF WESTWAY: LESSONS FROM ITS DEMISE". The New York Times. Retrieved March 22, 2018.
  18. ^ Gulf Oil Company; Rand McNally and Company (1960). New Jersey and Metropolitan New York (Map). 1:390,000. Chicago: Gulf Oil Company. Road map of metropolitan New York City inset. OCLC 986509183.
  19. ^ New York State Department of Transportation (January 1, 1970). Description of Touring Routes in New York State for the Interstate (I), Federal (U.S.) and State (N.Y.) Route Number Systems (PDF). Retrieved March 26, 2009.

External links[edit]

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