Interstate 78 in Pennsylvania
|Maintained by PennDOT & DRJTBC|
|Length:||75.23 mi (121.07 km)|
|West end:||I-81 In Union Township|
| US 22 in Union Township
PA 61 near Hamburg
US 22 in Upper Macungie Township
PA 309 from Dorneyville to Summit Lawn
PA 33 in Bethlehem Township
|East end:||I-78 at New Jersey state line in Williams Township|
Interstate 78 is an east–west route stretching from Union Township, Lebanon County, Pennsylvania to New York City. In the U.S. state of Pennsylvania, I-78 runs for about 77 miles (124 km), from the western terminus at Interstate 81 to the New Jersey state line; I-78 continues into New Jersey.
I-78 starts in Pennsylvania at an interchange with Interstate 81. It merges with U.S. Route 22 in Lebanon County, with the median strip becoming narrow at that point; the two run together for 43 miles (69 km) from Bethel Township to Kuhnsville. Near Kuhnsville, U.S. Route 22 splits off from I-78 and becomes the Lehigh Valley Thruway. Near Hamburg at mile marker 29, it meets a major Pennsylvania route: Pennsylvania Route 61. At mile marker 53, after the departure of US 22, Pennsylvania Route 309 merges with I-78 for 7 miles (11 km). Dorney Park & Wildwater Kingdom is visible from the freeway approaching exit 54 for U.S. Route 222, which leads to the park. In Summit Lawn, State Route 309 leaves the freeway toward Quakertown at exit 60. Past Allentown and Bethlehem, Pennsylvania Route 33 meets I-78 at exit 71. The last exit in Pennsylvania is Exit 75/Morgan Hill Road, which connects to Pennsylvania Route 611. The Interstate crosses the Delaware River on the Interstate 78 Toll Bridge, leaving Pennsylvania for New Jersey. Tolls are only required on the westbound side, coming into Pennsylvania.
Interstate 78 carries some additional name designations throughout Pennsylvania. In Lebanon County, Interstate 78 is known as the 78th Division Highway. In Berks County between mile marker 23 and mile marker 35, Interstate 78 is known as the CMSgt. Richard L. Etchberger Memorial Highway. In Lehigh and Northampton counties, Interstate 78 is known as the Walter J. Dealtrey Memorial Highway. The portion concurrent with US Route 22 shares its designation of the William Penn Highway.
Although built to modern-day Interstate Highway standards east of Pennsylvania Route 100, I-78 between PA-100 and the Berks-Lebanon county line was built mainly to 1960s standards and has characteristic soft shoulders in most locations. Interstate 78 between its western terminus with I-81 and exit 35 has a 65 mph (105 km/h) speed limit, while the portion from exit 35 to exit 60 has a 55 mph (89 km/h), with the final portion from exit 60 to the New Jersey line having a 65 mph (105 km/h). Prior to the late 1960s, I-78 was to be routed on the Lehigh Valley Thruway across to Phillipsburg, New Jersey, continuing the concurrency with US Route 22; however, because of heavy opposition by residents of Phillipsburg, PennDOT and NJDOT opted to build the new southerly alignment on which I-78 is routed today.
Interstate 178 was a proposed spur from Interstate 78, but was cancelled because the Liberty Bell Shrine was in the path of the proposed expressway. Additionally, locals opposed the destruction of Sixth and Seventh Streets to accommodate the highway. The planned northern terminus would have been between the 15th Street and PA 145 interchanges. If built, Interstate 178 would have connected US 22, formerly designated I-78 into Allentown.
Interstate 378 was the designation for a spur route that would extend from Interstate 78 into Bethlehem. At the time, I-78 was designated as the Lehigh Valley Thruway, concurrent with US 22, and the route numbering made sense. Unlike I-178, the route was built. When I-78 was later redirected south of this area, I-378 had no direct connection to I-78 and therefore was downgraded to state route status. The route still remains, as a freeway with exits and their own numbers. That is quite rare for a state route.
When Interstate 178 and 378 were planned (and 378 was built), I-78 ran the length of the Lehigh Valley Thruway. Later, I-78 was rerouted onto a bypass route south of the Thruway. This was due to opposition to continue the concurrency with the Thruway into New Jersey.
In 2013, PennDOT announced plans to improve a portion of I-78 in eastern Berks County. The project will redesign the PA 737 interchange, add truck lanes, and raise the height of three overpasses. Construction is expected to begin in 2015 with completion in 2018.
||Union Township||0.00||0.00||1A||I-81 south – Harrisburg||Westbound exit and eastbound entrance|
|0.55||0.89||1B||I-81 north – Hazleton||Westbound exit and eastbound entrance|
|Bethel Township||5.85||9.41||6||PA 343 – Lebanon, Fredericksburg||Eastbound exit and westbound entrance; northern terminus of PA 343|
|7.90||12.71||8||US 22 west to PA 343 – Lebanon, Fredericksburg||West end of US 22 overlap, westbound exit and eastbound entrance|
||Bethel Township||10.21||16.43||10||PA 645 – Frystown|
|Bethel||12.68||20.41||13||PA 501 – Bethel|
|Bethel Township||14.67||23.61||15||Grimes||No access across I-78, no tractor trailers|
|15.40||24.78||16||Midway||To Conrad Weiser Homestead|
|16.58||26.68||17||PA 419 – Rehrersburg|
|Strausstown||18.65||30.01||19||PA 183 – Strausstown|
|Upper Bern Township||22.71||36.55||23||Shartlesville|
|29||PA 61 – Reading, Pottsville||Signed as exits 29A (south) and 29B (north) on the westbound side|
|Greenwich Township||35.23||56.70||35||PA 143 – Lenhartsville|
|40.27||64.81||40||PA 737 – Kutztown, Krumsville||To Kutztown University|
||Weisenberg Township||44.96||72.36||45||PA 863 – Lynnport, New Smithville|
|Upper Macungie Township||49.26||79.28||49A||PA 100 south – Trexlertown|
|49.55||79.74||49B||PA 100 north – Fogelsville|
|50.89||81.90||51||US 22 east to I-476 / Penna. Tpk. NE Ext. / PA 309 north – LVI Airport||East end of US 22 overlap, eastbound exit and westbound entrance|
|South Whitehall Township||53.67||86.37||53||PA 309 north to Penna. Tpk. NE Ext. – Tamaqua||West end of PA 309 overlap, westbound exit and eastbound entrance|
|54||US 222 south / PA 222 north (Hamilton Boulevard)||Signed as exits 54A (south) and 54B (north) westbound, to Reading and Dorney Park & Wildwater Kingdom|
|Salisbury Township||55.41||89.17||55||PA 29 (Cedar Crest Boulevard)|
|57.63||92.75||58||Emaus Avenue south||Westbound exit only|
|Summit Lawn||58.83||94.68||59||To PA 145 – Summit Lawn||Eastbound exit and westbound entrance|
|59.92||96.43||60A||PA 309 south – Quakertown||East end of PA 309 overlap, signed as exit 60 eastbound|
|60.30||97.04||60B||PA 145 north (South 4th Street)||Westbound exit only|
||Hellertown||66.36||106.80||67||PA 412 – Hellertown, Bethlehem|
|Bethlehem Township||71.04||114.33||71||PA 33 north to US 22 – Stroudsburg||To Pocono Mountains and Lehigh Valley International Airport|
|Williams Township||75.00||120.70||75||To PA 611 – Easton, Philadelphia|
||77.10||124.08||Interstate 78 Toll Bridge|
||Phillipsburg||77.10||124.08||I-78 east||New Jersey border|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- Route Log - Main Routes of the Eisenhower National System Of Interstate and Defense Highways - Table 1
- Steve Esack (2004-01-30). "Section of I-78 named to honor businessman Walter J. Dealtrey - Morning Call". Articles.mcall.com. Retrieved 2013-01-29.
- "Pennsylvania's Dearly Departed Interstates".
- "I-178 (cancelled) Pennsylvania".
- "1963 Rand McNally".
- "I-178 Map".
- Devlin, Ron (January 18, 2013). "PennDOT unveils upgrade to Interstate 78". Reading Eagle. Retrieved January 18, 2013.
- Calculated using DeLorme Street Atlas USA 2007
|Wikimedia Commons has media related to Interstate 78 in Pennsylvania.|