The Pennsylvania Turnpike, sometimes shortened to Penna Turnpike or PA Turnpike, is a controlled-access toll road which is operated by the Pennsylvania Turnpike Commission (PTC) in Pennsylvania. It runs for across the southern part of the state, connecting Pittsburgh, Harrisburg and Philadelphia, and passes through four tunnels as it crosses the Appalachian Mountains. A component of the Interstate Highway System, it is part of I-76 between the Ohio state line and Valley Forge (running concurrently with I-70 between New Stanton and Breezewood), I-276 between Valley Forge and Bristol Township, and I-95 from Bristol Township to the New Jersey state line.
The turnpike's western terminus is at the Ohio state line in Lawrence County, where it continues west as the Ohio Turnpike. The eastern terminus is the New Jersey state line at the Delaware River–Turnpike Toll Bridge, which crosses the Delaware River in Bucks County. It continues east as the Pearl Harbor Memorial Extension of the New Jersey Turnpike. The turnpike has an all-electronic tolling system; tolls may be paid using E-ZPass or toll by plate, which uses automatic license plate recognition. Cash tolls were collected with a ticket and barrier toll system before they were phased out between 2016 and 2020. The turnpike currently has 15 service plazas, providing food and fuel to travelers.
The turnpike was designed during the 1930s to improve automobile transportation across the Pennsylvania mountains, using seven tunnels built for the South Pennsylvania Railroad in the 1880s. It opened in 1940 between Irwin and Carlisle. Branded as "America's First Superhighway", the turnpike, an early long-distance limited-access U.S. highway, was a model for future limited-access toll roads and the Interstate Highway System. It was extended east to Valley Forge in 1950 and west to the Ohio state line in 1951. The road was extended east to the Delaware River in 1954, and construction began on an extension into Northeastern Pennsylvania. The mainline turnpike was finished in 1956 with the completion of the Delaware River Bridge.
From 1962 to 1971, an additional tube was built at four of the two-lane tunnels, with two cuts built to replace the three others; this made the entirety of the road four lanes wide. Improvements continue to be made: rebuilding to meet modern standards, widening portions to six lanes, and construction or reconstruction of interchanges.
Route description
The turnpike runs west to east across Pennsylvania, from the Ohio state line in Lawrence County to the New Jersey state line in Bucks County. It passes through the Pittsburgh, Harrisburg, and Philadelphia areas, farmland and woodland. The highway crosses the Appalachian Mountains in central Pennsylvania, passing through four tunnels. The PTC, created in 1937 to construct, finance, operate, and maintain the road, controls the highway.
It is part of the National Highway System, a network of roads important to the U.S. economy, defense, and mobility. The turnpike is a Blue Star Memorial Highway, honoring those who have served in the United States Armed Forces, and the Garden Club Federation of Pennsylvania has placed Blue Star Memorial Highway markers at its service plazas. In addition to the east–west mainline, the PTC also operates the Northeast Extension (I-476), the Beaver Valley Expressway (I-376), the Mon–Fayette Expressway (PA 43), the Amos K. Hutchinson Bypass (PA 66), and the Southern Beltway (PA 576).
Western Extension
thumb|right|alt=Cars and trucks on four-lane, divided highway|Westbound approaching the Pittsburgh Interchange with I-376/US 22 in Monroeville
The turnpike begins at the Ohio state line in Lawrence County, where it continues west as the Ohio Turnpike. From the state line, the highway heads southeast as a four-lane freeway (I-76) through rural areas south of New Castle. A short distance from the Ohio line, the eastbound lanes pass the electronic Gateway toll gantry, where the road widens to six lanes. The highway then reaches Beaver County and the first interchange with I-376 (the Beaver Valley Expressway) in Big Beaver, narrowing back to four lanes.
It then passes under Norfolk Southern's Koppel Secondary rail line before the exit for PA 18 near Homewood, crossing CSX's Pittsburgh Subdivision rail line, the Beaver River, and Norfolk Southern's Youngstown Line on the Beaver River Bridge. The turnpike winds through a valley south of the river before traversing Clear Ridge Cut near Everett. In Breezewood, I-70 leaves the turnpike at an interchange with US 30 with some of the only traffic lights on an interstate highway. It then reaches Carlisle and an interchange with US 11, accessing I-81. At this point, the highway narrows to four lanes. to an interchange with PA 72, accessing Lebanon on the north and Lancaster on the south. It passes over an East Penn Railroad line in Denver before an indirect interchange with US 222, which serves Reading and Lancaster. The route continues into Berks County to an interchange with the southern terminus of I-176 (a freeway to Reading) and PA 10 in Morgantown which accesses PA 23.
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thumb|alt=Another stretch of road with sign, photographed from the shoulder|Eastbound, past the Mid-County Interchange with I-476 in Plymouth Meeting
At the Valley Forge Interchange, the turnpike is designated I-276 and becomes a suburban commuter highway. It crosses a bridge over SEPTA's Norristown High Speed Line and runs parallel to Norfolk Southern's Dale Secondary rail line, south of the road. The turnpike crosses Norfolk Southern's Harrisburg Line, the Schuylkill River, and SEPTA's Manayunk/Norristown Line on the Schuylkill River Bridge near Norristown. The road crosses the Schuylkill River Trail and Norfolk Southern's Morrisville Connecting Track on the Schuylkill River Bridge before the parallel Dale Secondary rail line runs south.
Major bridges and tunnels
thumb|alt=See caption|Aerial view of the [[Blue Mountain Tunnel|Blue Mountain and Kittatinny Mountain tunnels. The six-degree curve near the Blue Mountain Tunnel eastern portal was replaced during the early 2010s.]]
thumb|right|alt=Two tunnel entrances (two lanes in each direction)|West portal of the Allegheny Mountain Tunnel
The turnpike has several major bridges and tunnels. Four tunnels cross central Pennsylvania's Appalachian Mountains. The Allegheny Mountain Tunnel passes under Allegheny Mountain in Somerset County. The Tuscarora Mountain Tunnel runs beneath Tuscarora Mountain at the border of Huntingdon and Franklin counties, and is long. The Kittatinny Mountain and Blue Mountain tunnels are adjacent to each other in Franklin County and are and long, respectively. An eastbound mainline toll gantry is at Gateway (near the Ohio state line), and a westbound mainline toll gantry is at the Delaware River Bridge near the New Jersey state line; both charging a flat toll. No toll is collected for journeys between the New Castle and Cranberry Interchanges and between Neshaminy Falls and the Delaware River Bridge. Motorists received a ticket listing the toll for each exit; the ticket was surrendered when exiting, and the applicable toll was paid. If the ticket was lost, motorists were charged the maximum toll for that exit. Cash, credit cards, and E-ZPass were accepted at toll plazas. On March 6, 2012, the turnpike commission announced that it was implementing the plan. The turnpike commission projected that it would save $65 million annually in labor costs by eliminating toll collectors. On January 3, 2016, electronic tolling was introduced at the westbound Delaware River Bridge mainline toll plaza, and the eastern terminus of the ticket system was moved from the Delaware River Bridge to Neshaminy Falls. On October 27, 2019, electronic tolling was implemented at the eastbound Gateway mainline toll plaza. Electronic tolling was originally scheduled to be implemented on the entire length of the turnpike in late 2021.
By 2020, about 86 percent of turnpike vehicles already used E-ZPass for payment of tolls. In March 2020, the switch to electronic tolling was made early as a result of the COVID-19 pandemic. The electronic tolling system used toll booths at exits until toll gantries between interchanges were built. The first toll gantries on the Northeast Extension and on the mainline east of the Reading Interchange began operation in January 2025, and the remainder of the toll gantries along the western portion of the turnpike are expected to begin operation by late 2026. After all toll gantries are fully operating, the PTC plans to demolish all toll plazas.
Act 44, Act 89, and toll increases
Under a 2007 law, Act 44, the Turnpike has been mandated to provide $450 million, a sizable share of its revenue, annually to the Commonwealth of Pennsylvania and the Department of Transportation for transit and other purposes. The PTC, which previously had raised tolls only six times in 64 years, began to increase tolls every January 1. Its debt increased to be about equal to the entire General Obligation debt of the state. Turnpike spokesperson Carl DeFebo disputed Budget Direct's claim, saying that the analysis looked at all of the turnpike's toll roads together; "Nobody would ever go south towards Pittsburgh, east towards Philadelphia, then north towards Scranton. That's a 400-plus mile trip", and turnpike tolls are comparable to other toll roads on a per-mile basis. Towing service is available from authorized service stations near the highway, and Pennsylvania State Police Troop T patrols the turnpike. The troop's headquarters is in Highspire, and its turnpike substations are grouped into two sections. The western section has substations in Gibsonia, New Stanton, Somerset and Everett; the eastern section has mainline substations in Newville, Bowmansville and King of Prussia. The PTC broadcasts AM road, traffic, and weather conditions from highway advisory radio transmitters at each exit on 1640 kHz, with a range of approximately . The 511PA travel-information service provides alerts, an interactive map, weather information and traffic cameras to motorists, and variable-message signs located along the roadway provide information such as accidents, construction, weather, and traffic congestion.
Service plazas
thumb|alt=Entrance to building with pointed arch|Sideling Hill service plaza
The turnpike currently has 15 high capacity service plazas, though at one point had over 20 lower capacity plazas. Each plaza has several fast-food restaurants, a Sunoco gas station, and a 7-Eleven convenience store. Other amenities include ATMs, E-ZPass sales, free cellphone charging, Pennsylvania Lottery sales, picnic areas, restrooms, tourist information, Travel Board information centers, and Wi-Fi. The King of Prussia plaza has a welcome center, and the New Stanton and Sideling Hill plazas have seasonal farmers' markets. Several plazas offer E85 fuel, and New Stanton offers compressed natural gas; all have conventional gasoline and diesel fuel. Some plazas have electric vehicle charging stations. The Sunoco and 7-Eleven locations and the Subway at North Midway are operated by 7-Eleven, and the remaining restaurants and general upkeep are operated by Applegreen.
By 1946, a number of service plazas were expanded in order to accommodate booming popularity. Gulf Oil operated service stations on the extensions, and Howard Johnson's provided food service in sit-down restaurants.
In 1955, the North and South Somerset Service Plazas were both opened, replacing the eastbound only New Baltimore Plaza.
In 1957, the westbound New Stanton service plaza was built, and the Laurel Hill Plaza, located to the west of the western end of the Laurel Hill Tunnel, was closed.
In 1968, the Sideling Hill Plaza opened with the Sideling Hill/Rays Hill bypass. It is the only service plaza on the mainline turnpike to serve both eastbound and westbound traffic, and replaced the westbound only Cove Valley Plaza, which was demolished due to being located on the section of turnpike being bypassed.
The Pleasant Valley plaza was closed in January 1979, while the Denver and Mechanicsburg plazas closed in 1980.
All three were auctioned in October 1981, having been experiencing diminishing profits. This left only the Oakmont Plum, Butler, and Zelienople service plazas in western Pennsylvania.
In 1978, as Howard Johnson's exclusive contract to provide food service was ending, the turnpike commission entertained bids; Aramark was awarded a food-service contract at two plazas. In 1980, Hardee's opened restaurants at the service plazas to compete with Howard Johnson's. The turnpike was the world's first road to offer fast food at its service plazas. this was part of a deal that saw the eastbound Path Valley plaza closed, it had seen a gradual loss of revenue since the Sideling Hill plazas opening in 1968. With this, fast food was implemented at the Hempfield Plaza. This reflected increased demands for fast food. Marriott Corporation purchased the remaining Howard Johnson's restaurants in 1987, and restaurants such as Roy Rogers and Bob's Big Boy opened.
In April 1990, Gulf Oil LP replaced the turnpike's Exxon stations.
The Brandywine (later Peter J. Camiel) plaza was systematically demolished and rebuilt from September 1990 to May 1991. This was necessary as it was the busiest service plaza on the entire mainline, and as such, increased use of it over time had rendered it obsolete.
Sunoco took over gas-station operations in 1993, outbidding Shell US; credit card-activated pumps, fax machines, ATMs, and informational lodging boards were added.
In March 2002, the Butler plaza was closed so it could be replaced by the Warrendale Toll Plaza. Two years later, the Somerset Service Plaza was expanded.
The eastbound Zelienople plaza closed in 2008 due to being a money loser since the portion between the Gateway Toll Plaza and Warrendale became free in 2003. Some criticized this as a potential tourism reducer.
The North Neshaminy plaza closed in 2010 so its parking lot could be used for construction equipment needed for a planned total reconstruction in the area. Free Wi-Fi was introduced at all service plazas in 2013.
The Art Sparks program began in 2017 as a partnership between the turnpike commission and the Pennsylvania Council on the Arts to install public art created by local students in the Arts in Education residency program in service plazas along the turnpike over the next five years. The art consists of a mural reflecting a plaza's location. The first Art Sparks mural was unveiled at the Lawn service plaza in May of that year.
Beginning in April 2019, Sunoco/A-Plus locations began conversion to 7-Elevens as part of an agreement for 7-Eleven to take over Sunoco's company-owned convenience stores on the East Coast and in Texas; Sunoco continues to supply fuel.
History
Before the turnpike
Native Americans used east–west paths that usually traced river valleys and crossed the ridges of the Allegheny Mountains. European settlers followed wagon roads that often followed the same paths. The Philadelphia and Lancaster Turnpike opened between Lancaster and Philadelphia in 1794, the first successful turnpike in the United States. The road was paved with logs laid crosswise to the direction of travel, giving a bumpy ride but an improvement on dirt trails. In 1834, the Main Line of Public Works opened as a system of canals, railroads, and cable railways across Pennsylvania to compete with the Erie Canal in New York.
The Pennsylvania Railroad was completed between Pittsburgh and Philadelphia in 1854. During the 1880s, the South Pennsylvania Railroad was proposed to compete with the Pennsylvania. It was backed by William Henry Vanderbilt, head of the New York Central Railroad (the Pennsylvania's chief rival). Andrew Carnegie also provided financial support, since he was unhappy with the Pennsylvania Railroad rates. Construction began on the rival line in 1883, but stopped when the railroads reached an agreement two years later. After construction halted, the only vestiges of the South Pennsylvania were nine tunnels, some roadbed, and piers for a bridge over the Susquehanna River in Harrisburg. The highway would be a four-lane, limited-access road modeled on the German Autobahn and Connecticut's Merritt Parkway. The turnpike could also be a defense road, and construction costs could be reduced by using the abandoned South Pennsylvania Railroad tunnels. The turnpike's design would be uniform.
In February 1938, the commission began investigating proposals for $55 million in bonds to be issued for construction of the turnpike. A month later, Van Ingen and Company purchased $60 million (equivalent to $ in ) in bonds which they offered to the public. In April 1938, President Franklin D. Roosevelt approved a $24-million (equivalent to $ in ) grant from the Works Progress Administration (WPA) for the construction of the road, and the commonwealth contributed $29 million (equivalent to $ in ) toward the project.
The WPA grant received final approval, but plans were still made to sell bonds, and the first issue was planned for about $20 million (equivalent to $ in ). The reduced bond issue was due to the WPA grant.
In June, the Reconstruction Finance Corporation (RFC) announced that it would lend the commission sufficient funds to build the road. The RFC loan totaled $32 million (equivalent to $ in ), with a $26 million (equivalent to $ in ) grant from the Public Works Administration (PWA); this provided $58 million (equivalent to $ in ) for the turnpike's construction, and highway tolls would repay the RFC.
In October 1938, the turnpike commission agreed with the RFC and PWA that the RFC would purchase $35 million (equivalent to $ in ) in bonds in addition to the PWA grant. That month, a banking syndicate purchased the bond amount from the RFC.
In 1940, the highway opened between Irwin and Carlisle, being the first long-distance controlled-access highway in the United States. Other states implemented toll roads in the years after World War II. After the passage of the Federal Aid Highway Act of 1956, new highways were often built as part of the Interstate Highway System rather than as toll roads. The highway was extended east to Valley Forge in 1950, and west to the Ohio state line the following year. and temporary railroad tracks transported construction equipment. Concrete was used to line the tunnel portals. The seven tunnels - which included the Laurel Hill, Tuscarora Mountain, Kittatinny Mountain, and Blue Mountain - featured ventilation ducts, drainage structures, sidewalks, lighting, and telephone and signal systems. Lighting was installed on the roadway approaching the tunnel portals.
A number of bridge designs were used to cross the highway, including the concrete arch bridge, the through plate girder bridge, and the concrete T-beam bridge. Bridges used to carry the turnpike over other roads and streams included a concrete arch viaduct in New Stanton; at , it was the longest bridge on the original section of the turnpike. Other turnpike bridges included plate girder bridges, such as the bridge over Dunnings Creek in the Bedford Narrows. Smaller concrete T-beam bridges were also built. A total of 307 bridges were built along the original section of the turnpike.
Eleven interchanges were built, most of which were trumpet interchanges where all ramps merge at the toll booths. Lighting was installed approaching interchanges, along with acceleration and deceleration lanes. Large exit signs were used, and road signs had cat's-eye reflectors to increase visibility at night. Billboards were prohibited. In September 1940, the Pennsylvania Public Utility Commission ruled that trucks and buses could use the highway.
Since the turnpike's first section was built through a rural part of the state, food and gasoline were not readily available to motorists. Because of this, the commission decided to provide service plazas at intervals. The plazas would be made of native fieldstone, resembling Colonial-era architecture. In 1940, Standard Oil of Pennsylvania received a contract for 10 Esso service stations along the turnpike. Eight of the service plazas would consist of service stations and a restaurant, and the plazas at the halfway point (in Bedford) would be larger. The remaining service plazas were smaller, with a lunch counter. Food service at the plazas was provided by Howard Johnson's. After World War II, the food facilities were enlarged;
Construction and opening
thumb|alt=Four-lane highway with overpass, photographed from median|A view of the turnpike at an overpass in 1942
thumb|alt=Stairs from the turnpike to a church|Stairs to St. John's Church in New Baltimore in 2010
Before the first-section groundbreaking, in 1937, the turnpike commission sent workers to assess the former railroad tunnels; in September of that year, a contract was awarded to drain water from them. After this, workers cleared rock slides and vegetation from the tunnel portals before evaluating the nine tunnels' condition. It was decided that six of the nine former South Pennsylvania Railroad tunnels could be used for the roadway. The Allegheny Mountain Tunnel was in too-poor condition for use. Because of this, an entirely new tunnel was bored nearby. However of these nine, it would be more expensive to complete the Quemahoning and Negro Mountain tunnels in comparison to simply building rock cuts to bypass them. As such, they were bypassed in original construction. Construction was on a tight schedule because completion of the road was originally planned by May 1, 1940. After the groundbreaking, contracts for finishing the former South Pennsylvania Railroad tunnels, grading the turnpike's right of way, constructing bridges, and paving were issued. By July 1939, the entire length of the turnpike was under contract.
The first work to begin on the road was grading its right of way, which involved a great deal of earthwork due to the mountainous terrain. Concrete culverts were built to carry streams and roads under the highway in the valley floor. The Clear Ridge cut was deep (the deepest highway cut in the United States at the time), and was known as "Little Panama" after the Panama Canal. West of Clear Ridge, cuts and fills were built for the turnpike to pass along the southern edge of Earlston.
Considerable work was involved in building the road up the three-percent grade at the east end of Allegheny Mountain, the turnpike's steepest grade. The base of Evitts Mountain was blasted to carry the turnpike across Bedford Narrows with US 30, the Raystown Branch of the Juniata River, and a Pennsylvania Railroad branch line. Concrete batch plants were set up along the road to aid paving. Interchange ramps were paved with asphalt. That month, a military motorcade traveled portions of the turnpike.
Paving concluded by the end of the summer, and on September 30 the turnpike commission announced that the road would open the following day. Because of the short notice, no ribbon-cutting ceremony was held.
The roadway took of sand, of stone, of steel, and more than of cement to complete. Eighteen thousand people worked on the turnpike, and 19 died during construction.
When the highway was under construction, its proposed toll was $1.50 (equivalent to $ in ) for a one-way car trip; a round trip would cost $2.00 (equivalent to $ in ). Trucks would pay $10.00 (equivalent to $ in ) one way. Tolls would vary for motorists who did not travel the length of the turnpike. The toll rate was about (equivalent to in ) when the turnpike opened. The ticket system was used to pay for tolls. Boe was flagged down by Frank Lorey and Dick Gangle, the turnpike's first hitchhikers. On October 6 (the first Sunday after the turnpike's opening), traffic was congested at toll plazas, tunnels, and service plazas.
During its first 15 days of operation, the road had over 150,000 vehicles. By the end of its first year it earned $3 million (equivalent to $ in ) in revenue from five million motorists, exceeding the $2.67 million (equivalent to $ in ) needed for operation and bond payments. With the onset of World War II, revenue declined due to tire and gas rationing; after the war, traffic increased.
thumb|alt=Overgrown tunnel entrance with graffiti|Western portal of the [[Rays Hill Tunnel in 2023]]
The turnpike was the first long-distance, limited-access road in the United States. A direct link between the mid-Atlantic and midwestern states, it reduced travel time between Pittsburgh and Harrisburg by hours; for example, Greyhound buses had taken nearly nine hours, but now took just , including a rest stop. Nicknamed "dream highway" and "the World's Greatest Highway" by the turnpike commission, Postcards and other souvenirs promoted the original stretch's seven tunnels through the Appalachians.
The highway was considered a yardstick against which limited-access highway construction would be measured. Commission chair Jones called for more limited-access roads to be built across the country for defense purposes, The turnpike led to the construction of other toll roads, such as the New Jersey Turnpike and (eventually) the Interstate Highway System,
1940s–1990s
The turnpike had no speed limit at all when it opened. The only exception was at the tunnels, where it reduced to . However, these were poorly enforced, some cars traveled as fast as . In April 1941, speed limit was raised from for cars and for trucks.
Beginning in December 1941, the turnpike adopted the national speed limit of for all vehicles;
thumb|alt=A four-lane highway, seen from an overpass|Westbound in [[Charlestown Township, Pennsylvania|Charlestown Township]]
Before the first section opened, the commission considered extending east to Philadelphia for defense purposes. The state legislature passed a 1939 bill allowing for an extension to Philadelphia, which was signed into law by Governor Arthur James as Act 11 in 1940. In June 1948, funding for the extension was put in place. The turnpike commission offered $134 million (equivalent to $ in ) in bonds to pay for the extension that July, which had its estimations revised to $87 million. The Philadelphia extension would run from Carlisle east to US 202 in King of Prussia, connecting to the Schuylkill Expressway, a state-maintained freeway which would continue to Center City Philadelphia. Groundbreaking for the Philadelphia extension took place on September 28, 1948, in York County. Governor James H. Duff and commission chair Thomas J. Evans attended the ceremony.
In June 1941, Governor Arthur James signed Act 54 into law to build an extension to the Ohio border. That September, $77 million (equivalent to $ in ) in bonds were sold to finance construction of the western extension. Groundbreaking for the Western extension took place on October 24, 1949 at the Brush Creek viaduct in Irwin, with Governor Duff in attendance. These extensions would use air-entrained concrete poured on stone, an improvement that motorists did not see. Transverse joints on the pavement were spaced at intervals, less than the intervals on the original portion. Large bridges were built, including those crossing the Susquehanna River and Swatara Creek. This extension of the turnpike would use the same style of overpasses as the original section, excluding the steel deck bridge; an entirely new design. Overpasses were steel- and through-plate girder bridges. Concrete arch bridges were not used for overpasses, although they carried the turnpike over other roads. thirteen interchanges were built alongside the extensions, as well as the Gateway Toll Plaza and Valley Forge Toll Plaza, which served as the new eastern and western termini of the ticket system. The Carlisle Interchange was also closed, and the Middlesex Interchange with US 11 was realigned and renamed the Carlisle Interchange, The Irwin Interchange was also converted into the Irwin Toll Plaza. The extension's completion was delayed by weather and a cement workers' strike; it was scheduled for October 1, 1950, the 10th anniversary of the opening of the first section. On October 23, the Philadelphia extension was previewed in a ceremony by Governor Duff. On November 13, the new Carlisle Interchange was opened as planned. However, drivers were barred from passing east of the new interchange. The rest of the Philadelphia extension opened to traffic on November 20; the governor and chair Evans cut the ribbon at the Valley Forge mainline toll plaza west of King of Prussia. Similarly to the Carlisle Interchange, the Irwin Toll Plaza was replaced by the Irwin Interchange, however, as the new alignment passed to the east of the Irwin Toll Plaza, the original toll plaza was retained. The extension opened to the Gateway toll plaza, near the Ohio state line, on December 26, 1951. The highway ended in a cornfield, and traffic followed a temporary ramp onto rural local roads until the connecting Ohio Turnpike was built. On December 1, 1954, the Ohio Turnpike opened and the Pennsylvania Turnpike was extended to the Ohio state line. With the completion of this project, an extra were added to the system, leaving a total length of . Because of the new western terminus, mile markers and exit numbers on the original were updated to be accurate to the new western terminus.
On May 17, 1956, the speed limit was reduced from for cars, buses, and motorcycles; other vehicles were reduced from .
thumb|alt=Three lanes of a six-lane highway, with two signs|Westbound, approaching the Mid-County Interchange with I-476 in Plymouth Meeting
In 1951, plans to extend the turnpike east to New Jersey border at the Delaware River were announced. Construction of the Delaware River extension was approved by Governor John S. Fine in May of that year. A route bypassing Philadelphia was announced in 1952, crossing the Delaware on a bridge near Edgely and connecting to a branch of the New Jersey Turnpike. That September, the turnpike commission announced that $65 million, equivalent to $ in , in bonds would be issued to finance the project. Work on the Delaware River extension began on November 20, 1952, and Governor Fine dug the first shovel into the earth at the groundbreaking ceremony. Five new interchanges, as well as the Delaware River Bridge Toll Plaza, were built, and the Valley Forge Toll Plaza was demolished and replaced by the Valley Forge Interchange. The Delaware River extension included a bridge over the Schuylkill River which was built to the same standards as the Susquehanna River Bridge. The construction of the Delaware River bridge required an amendment to the Pennsylvania Constitution, which barred the state from forming compacts with other states. In April 1954, $233 million (equivalent to $ in ) in bonds were issued to finance the building of the Delaware River Bridge and the Northeast Extension. Groundbreaking for the Delaware River Bridge, connecting the Pennsylvania and New Jersey Turnpikes, took place on June 26, 1954, in Florence, New Jersey. On August 23, 1954, the Delaware River Extension opened between King of Prussia and US 611 in Willow Grove. the segment to the Fort Washington Interchange opened on September 20, to the Philadelphia Interchange on October 27, Pennsylvania Governor George M. Leader and New Jersey Governor Robert B. Meyner were present at the opening ceremony. The Delaware River Bridge Toll Plaza was built west of the bridge, marking the eastern end of the ticket system. With the completion of the extension, a motorist could drive from New York City to Indiana on limited-access toll roads. With the extensions and connecting turnpikes, the highway was envisioned as part of a system of toll roads stretching from Maine to Chicago. It was now possible to drive from New York City to Chicago without encountering a traffic signal. This brought the mainline to its current length of .
In late 1956, new machine-based toll equipment was activated for trucks, allowing for faster, more accurate tolls.
In 1953, an extension of the Pennsylvania Turnpike from the mainline near Plymouth Meeting north through Northeastern Pennsylvania to the New York state line near Binghamton, New York, was proposed. Groundbreaking for the Northeastern Extension occurred on March 25, 1954, in White Haven, with Governor John S. Fine and commission chair Thomas J. Evans present. The Northeast Extension was planned to run from the mainline Pennsylvania Turnpike in Plymouth Meeting north to a temporary terminus at Scranton. In April 1954, $233 million (equivalent to $ in ) in bonds were issued to build the Northeastern Extension along with the Delaware River–Turnpike Toll Bridge on the mainline Pennsylvania Turnpike. The Northeast Extension was built with a median in order to save money. Due to the mountainous terrain it passed through, a large amount of earthwork was necessary to build the road along with the construction of large bridges. Among the bridges built was the Clarks Summit Bridge (since renamed for John J. Fitzgerald, Turnpike engineer and superintendent) over US 6/US 11, which at the time was the tallest bridge on the Pennsylvania Turnpike system at . The Northeast Extension also included the two-lane Lehigh Tunnel under Blue Mountain. The tunnel was originally going to be named for commission chair Evans but was changed when he was convicted of conspiracy to defraud the commission of $19 million (equivalent to $ in ). The entire length of the Northeast Extension was finished on November 7, 1957, with the completion of the northernmost part between Wyoming Valley and Scranton. The part of the Northeast Extension between Scranton and the New York state line was not built as part of the Pennsylvania Turnpike system but rather the Interstate Highway System as I-81. At the northern terminus, the Northeast Extension narrowed to two lanes along the northbound offramp at Scranton to come to its northern terminus just outside Clarks Summit, with an abandoned short spur of the mainline heading north. A pair of trumpet interchanges were built to connect the Northeast Extension and I-81. I-80 was planned to run along the turnpike from the Ohio state line and Harrisburg West Interchange, where I-80S would continue east to the Valley Forge Interchange. I-70 was also planned to follow the turnpike between the Pittsburgh Interchange and Breezewood Interchange. At a June 26, 1958 meeting of the Route Numbering Subcommittee on the US Numbered System, it was decided to move the I-80 designation to an alignment further north; the highway from the Ohio state line to the Valley Forge Interchange would become I-80S. Between the Valley Forge Interchange and the New Jersey state line, the turnpike was designated I-280. With the creation of the Interstate Highway System, restaurants and gas stations were prohibited along interstate highways; the turnpike was grandfathered when it joined the system, allowing it to continue operating its service plazas. Signage was updated to be of a MUTCD standard with this change.
In July 1959, a minimum speed of was established.
By the early 1950s, it was apparent that the original concrete driving surface between the Irwin Interchange and Carlisle Interchange was in poor shape. This was caused by excessive transverse-joint spacing and no gravel between earth and concrete. Because of this, a project began in 1954 to layer the original turnpike segment between Irwin and Carlisle with a layer of asphalt. Drainage was also implemented in order to prevent black ice from forming during cold weather, which was previously a common problem. During the work, traffic was restricted to two lanes on one roadway while the other was worked on. The first stretch to be rehabilitated was the stretch between the Irwin Interchange and Sideling Hill Tunnel. Repaving the rest of the roadway was completed by September 8, 1962.