I-78 highlighted in red
|Maintained by PennDOT and DRJTBC|
|Length||75.23 mi (121.07 km)|
|History||Completed in 1989|
|West end||I-81 In Union Township|
| US 22 from Bethel Township to Upper Macungie Township|
PA 501 in Bethel
PA 183 near Strausstown
PA 61 near Hamburg
PA 100 in Fogelsville
PA 309 from Dorneyville to Summit Lawn
US 222 / PA 222 near Dorneyville
PA 29 near Allentown
PA 33 in Lower Saucon Township
|East end||I-78 at the New Jersey state line in Williams Township|
|Counties||Lebanon, Berks, Lehigh, Northampton|
Interstate 78 (I-78) is an east–west Interstate Highway stretching from Union Township in Lebanon County, Pennsylvania east 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 I-81 in Union Township, Lebanon County east to the New Jersey state line near Easton, Northampton County.
Much of I-78 west of Allentown predates the Interstate Highway System as a freeway upgrade of U.S. Route 22 (US 22), which runs concurrently with I-78 between Bethel Township and Upper Macungie Township. The Interstate, originally planned as I-80N, was supposed to continue its concurrency with US 22 to the New Jersey state line, but was realigned to the south due to local opposition. Two auxiliary routes, I-178 and I-378, were also planned; I-178 was never built while I-378 became Pennsylvania Route 378 (PA 378) as it no longer connected to I-78. Improvement of the highway in Berks County is currently underway.
Lebanon and Berks counties
I-78 begins at an interchange with I-81 in Union Township in Lebanon County, heading east as a four-lane freeway. In Lebanon County, I-78 is known as the 78th Division Highway. The road passes under PA 72 and turns northeast through a mix of farmland and woodland, crossing the Swatara Creek into Swatara Township. The freeway continues through agricultural areas with some trees, curving east and entering Bethel Township. I-78 passes north of the community of Fredericksburg and comes to an eastbound exit and westbound entrance with the northern terminus of PA 343. Following this, the freeway passes through more rural areas with some nearby development and reaches a westbound exit and eastbound entrance with US 22 (William Penn Highway). At this point, US 22 becomes concurrent with I-78 and the median of the freeway narrows from a grassy median to a Jersey barrier.
I-78/US 22 enters Bethel Township in Berks County and heads east-northeast through agricultural areas to the south of the Blue Mountain ridge, coming to a diamond interchange with PA 645 north of the community of Frystown. The road continues through farmland with some warehouses and reaches a diamond interchange with PA 501 north of the community of Bethel. The freeway heads through a mix of farms and woods, passing to the south of Grimes Airport and coming to a right-in/right-out interchange with Court Street eastbound and Frantz Road westbound; this interchange has no access across the freeway. I-78/US 22 soon reaches a diamond interchange with Midway Road as it passes through more rural land, coming to a diamond interchange with PA 419 south of the community of Schubert. Past this interchange, the road runs through a mix of farms and woods, crossing the Little Swatara Creek into Upper Tulpehocken Township. The freeway reaches a diamond interchange with PA 183 north of the community of Strausstown and continues through agricultural areas with some woodland. I-78/US 22 crosses Northkill Creek into Upper Bern Township and comes to a diamond interchange with Mountain Road north of the community of Shartlesville. At this point, I-78/US 22 becomes the CMSgt. Richard L. Etchberger Memorial Highway, in honor of Richard Etchberger. Following this interchange, the road heads northeast through farm fields with some trees and homes and crosses into Tilden Township.
In Tilden Township, freeway continues northeast and reaches a partial cloverleaf interchange with PA 61 in a business area that includes a 250,000-square-foot (23,000 m2) Cabela's store. Past PA 61, I-78/US 22 comes to a bridge over the Reading Blue Mountain and Northern Railroad's Reading Division line and the Schuylkill River. Upon crossing the Schuylkill River, I-78/US 22 enters the borough of Hamburg and passes through residential areas, coming to a diamond interchange at North 4th Street that serves Hamburg. The road leaves Hamburg for Windsor Township and heads through agricultural areas with some woods and homes, curving to the east. Farther east, the parallel Blue Mountain ridge heads further north from the freeway. I-78/US 22 crosses into Greenwich Township and comes to a partial cloverleaf interchange with PA 143 north of the borough of Lenhartsville. The CMSgt. Richard L. Etchberger Memorial Highway name for I-78/US 22 ends at this interchange. Past this interchange, the road crosses Maiden Creek and runs through a mix of farm fields and woodland. Farther east, the freeway reaches a diamond interchange with PA 737 south of the community of Krumsville. The road continues east through rural land with some nearby development, passing through the northern corner of Maxatawny Township.
Lehigh and Northampton counties
I-78/US 22 enters Weisenberg Township in Lehigh County, where the freeway becomes the Walter J. Dealtrey Memorial Highway and continues east through farms and woods in the Lehigh Valley, passing north of the community of New Smithville. The road passes south of warehouses and comes to a diamond interchange with PA 863. Following this interchange, the freeway heads to the south of more warehouses and runs through more rural areas with some homes, crossing into Upper Macungie Township. I-78/US 22 runs between farm fields to the north and warehouses and industrial development to the south before it comes to a cloverleaf interchange with PA 100 in a business area in the community of Fogelsville. After the PA 100 interchange, the freeway widens to six lanes and heads east through industrial areas, coming to a bridge over Norfolk Southern's C&F Secondary railroad line before curving northeast. In the community of Kuhnsville, US 22 splits from I-78 at an eastbound exit and westbound entrance by heading northeast on the Lehigh Valley Thruway. From here, I-78 continues east-southeast as a four-lane freeway, passing residential subdivisions with some commercial development. The freeway continues southeast and passes over I-476 (Pennsylvania Turnpike Northeast Extension) before it comes to a westbound exit and eastbound entrance with the PA 309 freeway.
At this point, PA 309 becomes concurrent with I-78 and the freeway enters Lower Macungie Township, widening to six lanes and running past commercial development to the southwest of Dorney Park & Wildwater Kingdom. The freeway reaches a partial cloverleaf interchange with the northern terminus of US 222 and the southern terminus of PA 222 at Hamilton Boulevard, which provides access to the cities of Allentown and Reading. Following this interchange, the road crosses into South Whitehall Township and heads east between residential areas to the north and farm fields to the south before entering Salisbury Township and heading north of Lehigh Valley Hospital-Cedar Crest. Past the hospital, I-78/PA 309 comes to an interchange with the northern terminus of the southern section of PA 29 at Cedar Crest Boulevard before running between residential areas to the north and office buildings to the south. The freeway enters the city of Allentown and runs through woodland, crossing Little Lehigh Creek before it passes through a small section of Salisbury Township. The road heads back into Allentown and runs near residential areas, passing south of Allentown Queen City Municipal Airport before it comes to the Lehigh Street exit. I-78/PA 309 runs near industrial areas and passes over Norfolk Southern's Reading Line before coming to a westbound exit ramp serving Emaus Avenue. The freeway passes near neighborhoods before it leaves Allentown for Salisbury Township, where it ascends forested South Mountain. The highway comes to an eastbound exit and westbound entrance with Rock Road that provides a connection to PA 145 in Summit Lawn, at which point it crosses into Upper Saucon Township. Following this, the freeway turns southeast and comes to an interchange with the southern terminus of PA 145, at which point PA 309 splits from I-78 by heading southeast on a surface road toward Quakertown. From here, I-78 turns northeast, narrowing to four lanes with the median changing from a Jersey barrier to a grassy median. The road heads between South Mountain to the northwest and a mix of farm fields, woods, and development to the southeast.
I-78 enters Lower Saucon Township in Northampton County and passes over PA 378 as it curves north near residential development. The road turns to the east-northeast and runs between forested South Mountain to the north and farmland and homes to the south, entering the city of Bethlehem. The freeway crosses the Saucon Creek and becomes the border between Bethlehem to the north and the borough of Hellertown to the south before it comes to a partial cloverleaf interchange with PA 412 that serves Bethlehem and Hellertown. Following this interchange, I-78 fully enters Bethlehem before it crosses back into Lower Saucon Township, turning to the northeast and running through wooded areas with some farm fields and homes, heading across the East Branch Saucon Creek. The road comes to a trumpet interchange with the southern terminus of the PA 33 freeway, which heads north toward the Pocono Mountains region. Past this interchange, the freeway crosses into Williams Township and continues through rural areas with some development, crossing into the borough of Glendon. I-78 turns east as it passes south of industrial areas, leaving Glendon for Williams Township. The road comes to a diamond interchange with Morgan Hill Road, which heads north into the city of Easton and provides access to PA 611 via city streets. Past this interchange, the freeway widens to six lanes and passes near residential and commercial development, coming to a westbound welcome center and a westbound toll plaza for the Interstate 78 Toll Bridge. From here, I-78 runs through wooded areas and turns southeast, heading onto the Interstate 78 Toll Bridge which carries the freeway over PA 611 and the Delaware Canal before crossing the Delaware River, where I-78 leaves Pennsylvania for New Jersey.
Construction of the freeway between Lebanon and Lehigh counties took place between 1950 and 1970, originally as an upgraded alignment of US 22. All of I-78 was completed by 1989. When the Interstate Highway System numbers were first assigned in 1957, the route was planned as I-80N. 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 22; however, because of heavy opposition by residents of Phillipsburg, the Pennsylvania Department of Transportation (PennDOT) and the New Jersey Department of Transportation 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.
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.
Improvements in Berks County
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, widen lanes and shoulders, and raise the height of three overpasses. Construction began in 2015 and is planned to be completed in 2025 at a cost of $412.6 million.
|Lebanon||Union Township||0.00||0.00||1B||I-81 south – Harrisburg||Exit 89 on I-81|
|0.55||0.89||1A||I-81 north – Hazleton|
|Bethel Township||5.85||9.41||1||6||PA 343 south – Lebanon, Fredericksburg||Eastbound exit and westbound entrance; northern terminus of PA 343|
|7.90||12.71||1||8||US 22 west to PA 343 – Lebanon, Fredericksburg||Western terminus of US 22 concurrency; westbound exit and eastbound entrance|
|Berks||Bethel Township||10.21||16.43||2||10||PA 645 – Frystown|
|12.68||20.41||3||13||PA 501 – Bethel|
|14.67||23.61||4||15||Grimes||Right-in/right-out; access via Court Street eastbound, Frantz Road westbound; no access across I-78/US 22; no tractor trailers|
|15.40||24.78||5||16||Midway||Access via Midway Road; to Conrad Weiser Homestead|
|16.58||26.68||6||17||PA 419 – Rehrersburg|
|Upper Tulpehocken Township||18.65||30.01||7||19||PA 183 – Strausstown|
|Upper Bern Township||22.71||36.55||8||23||Shartlesville||Access via Mountain Road|
|9||29||PA 61 – Reading, Pottsville||Signed as exits 29A (south) and 29B (north) westbound|
|Hamburg||30.19||48.59||10||30||Hamburg||Access via North 4th Street|
|Greenwich Township||35.23||56.70||11||35||PA 143 – Lenhartsville|
|40.27||64.81||12||40||PA 737 – Kutztown, Krumsville||To Kutztown University|
|Lehigh||Weisenberg Township||44.96||72.36||13||45||PA 863 – Lynnport, New Smithville|
|Upper Macungie Township||49.26–|
|14||49||PA 100 – Trexlertown, Fogelsville||Signed as exits 49A (south) and 49B (north)|
US 22 east to I-476 / Penna Turnpike NE Extension / PA 309 north – LVI Airport
|Eastern terminus of US 22 concurrency; eastbound exit and westbound entrance|
|Lower Macungie Township||53.67||86.37||53|
PA 309 north to I-476 / Penna Turnpike NE Extension – Tamaqua
|Western terminus of PA 309 concurrency; westbound exit and eastbound entrance|
|Lower Macungie–South Whitehall|
|16||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||17||55||PA 29 south (Cedar Crest Boulevard)|
|57.63||92.75||18B||58||Emaus Avenue south||Westbound exit only|
|Upper Saucon Township||58.83||94.68||19||59||To PA 145 – Summit Lawn||Eastbound exit and westbound entrance; access via Rock Road|
|59.92||96.43||20A||60A||PA 309 south – Quakertown||Eastern terminus of PA 309 concurrency; signed as exit 60 eastbound; to DeSales University|
|60.30||97.04||20B||60B||PA 145 north (South 4th Street)||Westbound exit only; to Allentown Center City|
|Northampton||Bethlehem||66.36||106.80||21||67||PA 412 – Hellertown, Bethlehem||To Lehigh University and Wind Creek Bethlehem|
|Lower Saucon Township||71.04||114.33||71||PA 33 north to US 22 – Stroudsburg||Southern terminus of PA 33; to Pocono Mountains and Lehigh Valley Airport|
|Williams Township||75.00||120.70||22||75||To PA 611 – Easton, Philadelphia||Access via Morgan Hill Road|
|Rest area and welcome center (westbound)|
|Toll plaza (westbound only)|
|Delaware River||77.10||124.08||Interstate 78 Toll Bridge|
|—||I-78 east – New York City||Continuation into New Jersey|
|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". Federal Highway Administration. Retrieved 4 October 2014.
- Google (October 16, 2019). "Interstate 78 in Pennsylvania" (Map). Google Maps. Google. Retrieved October 16, 2019.
- Lebanon County, Pennsylvania Highway Map (PDF) (Map). PennDOT. 2019. Retrieved October 16, 2019.
- Berks County, Pennsylvania Highway Map (PDF) (Map). PennDOT. 2019. Retrieved October 16, 2019.
- 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.
- Lehigh County, Pennsylvania Highway Map (PDF) (Map). PennDOT. 2019. Retrieved October 16, 2019.
- Northampton County, Pennsylvania Highway Map (PDF) (Map). PennDOT. 2019. Retrieved October 16, 2019.
- Official Route Numbering for the National System of Interstate and Defense Highways (Map). American Association of State Highway Officials. August 14, 1957. Retrieved January 3, 2017.
- "Interstate-Guide: Interstate 78". www.interstate-guide.com. Retrieved March 26, 2016.
- "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.
- Winfrey, Katiera; Wivell, Dawn (March 7, 2019). "PennDOT, Berks Planning Commission provide update on I-78". 69 News. Retrieved March 16, 2019.
- Calculated using DeLorme Street Atlas USA 2007
- "Pennsylvania Exit Numbering" (PDF). Pennsylvania Department of Transportation. Retrieved October 2, 2007.
|Wikimedia Commons has media related to Interstate 78 in Pennsylvania.|
- Interstate 78 exits in Pennsylvania
- Steve Anderson's PhillyRoads.com: Allentown Spur Route (unbuilt I-178)
- Steve Anderson's PhillyRoads.com: Bethlehem Spur Route (PA 378, former I-378)