FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)

“An unbroken ribbon of concrete cutting through mountains and across valleys, bypassing towns. No stop signs, no intersections, no speed limits. The Pennsylvania Turnpike was the first of its kind and received nationwide acclaim as an engineering marvel.

It was touted as America’s first superhighway when it opened on October 1, 1940, and was the national standard for superhighway design and engineering.” That is how the Pennsylvania Turnpike Commission (PTC) describes the Pennsylvania Turnpike on its website.  Beginnings Decades before construction on the Turnpike began, though, its original route was envisioned by William H.

Vanderbilt as a railroad from Harrisburg to Pittsburgh. It was the 1880s, and Vanderbilt wanted to add to his railroad holdings (the New York City & Hudson River Railroad [NYC&HRR]) and build an alternative to the rival Pennsylvania Railroad. He secured the right-of-way for the proposed South Pennsylvania Railroad Company and a two-track roadbed with nine tunnels was planned. 

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)William H. Vanderbilt. (Image:

Tunnel excavation began in early 1884, and construction continued through 1884 and 1885. However, the project was halted after banker J.

Pierpont Morgan won a board seat on the NYC&HRRR and he and the railroad’s president sold the South Pennsylvania Railroad Company’s right-of-way to George B. Roberts, president of the Pennsylvania Railroad. Vanderbilt had spent £10 million on the railroad and 26 men died in construction accidents. (£10 million in 1885 is the equivalent of £2.82 billion today.) The unfinished project was termed “Vanderbilt’s Folly.”

About 25 years later, early cars and trucks were starting to spill out of the major cities and using the rudimentary roads (that had been built for horses and carts) to transport people and freight. 

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)

By 1910, some were proposing to convert Vanderbilt’s abandoned railway route into a motorway. The idea of a turnpike across the Allegheny Mountains gained support over the next two decades, (including support from the trucking industry).

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)Part of the roadbed that was built originally for the South Pennsylvania Railroad. (Photo: Pennsylvania State Archives)

Action in the 1930s In late 1934, Victor Lecoq, an employee with the Pennsylvania State Planning Board, and William Sutherland, who was with the Pennsylvania Motor Truck Association, proposed building a toll highway utilizing the old railroad bed and tunnels. Pennsylvania State Rep.

Cliff S. Patterson embraced the idea, and on April 23, 1935, he introduced House Resolution 138 to authorize a feasibility study. The stock market crash of 1929 led to the Great Depression.

Franklin Roosevelt had been elected president in 1932 and took office in March 1933 on the promise of ending the financial calamity. The Roosevelt administration, was promoting work-relief projects to cut the unemployment rate, and what became the Pennsylvania Turnpike was approved.

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)The stock market crash of 1929.

Construction costs were estimated at between £60 million and £70 million. The surveyor’s report was favorable; after learning this Governor George Earle signed Act 211 on May 21, 1937.

This established the Pennsylvania Turnpike Commission, and the first commission members were named on June 4. Despite the fact that the project’s financing was not yet in place, the first contract was awarded to a Pittsburgh-based contractor for removal of water from the existing tunnels. The final approval for federal financing occurred on October 10, 1938.

The first construction contract was advertised for bids four days later. The contract covered a 10-mile segment of the Turnpike in Cumberland County. However, no rights-of-way had been purchased. 

The Turnpike’s General Counsel (John Faller) went to talk to the farmer who owned the land that was proposed as the future right-of-way. Faller and representatives from the federal Public Works Administration (PWA) and the Reconstruction Finance Corporation were met by 200-300 farmers and others who lived nearby. Faller and the federal officials spoke to the landowner’s wife.

She agreed to sell the tract to the state, and then asked them for their autographs. When Jones asked her why she wanted the autographs, she said, “Mr. Jones, I want these autographs so that my children can say that they saw history being made that day when the greatest highway, a new era of road building, was started.”

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)Groundbreaking ceremonies on October 27, 1938. Walter Jones, the commission chairman, turns the first spade of dirt. (Photo: Pennsylvania State Archives)

Prior to construction, the PTC relied on funds from the federal government, the Pennsylvania Department of Highways, and loans from private industry. The project’s Chief Engineer, Samuel W.

Marshall, supervised 115 engineers at the beginning, but the number of engineers grew to more than 1,100 within three months. The large staff was necessary in order to meet the construction-season cycle, as well as the completion deadline set by the federal government.   The £29 million grant from the federal PWA came with strings – a completion date of June 1, 1940, by which “the highway should be substantially complete” – a very short 20-month deadline that is unimaginable today!

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)An early publicity map showing the highway with nine tunnels (pared to seven tunnels).
(Photo: Pennsylvania Turnpike Commission)

Building the Turnpike

The design of the turnpike was different from earlier highways, which had been built with flat curves to discourage speeding. But the turnpike was going to be a different type of highway, with easy grades to allow cars and trucks to use the road at higher speeds year-round. The engineers designed the turnpike with “long, sweeping curves” that provided room for high speeds and safe stopping distances.

The following standards were part of the design process:

  • A right-of-way width of 200 feet.
  • A four-lane divided configuration, with 12-foot-wide concrete traffic lanes, a 10-foot-wide median strip and 10-foot-wide shoulders, for a total width of 78 feet. 
  • A maximum grade of 3% (3 feet of climb for every 100 feet of forward travel), compared to hills as steep as 9% to 12% on Pennsylvania’s two-lane William Penn Highway (US 22) and Lincoln Highway (US 30).
  • A maximum curvature of 6 degrees, most of which occurred on the climb from New Baltimore to the Allegheny Tunnel;  however, most curves were only 3% to 4%.
  • Substantial super-elevation, or banking, on curves.
  • Limited access, with 1,200-foot-long entrance and exit ramps to provide room to accelerate and decelerate.
  • A minimum 600-foot sight distance from motorist to traffic ahead.
  • No cross streets, driveways, traffic signals, crosswalks or railroad grade crossings. All vehicular or pedestrian traffic would go over or under the Turnpike. Along the same distance on the Lincoln Highway and US 11, there were 939 cross streets, 12 railroad crossings and 25 traffic signals.

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)The crew of the L.M. Hutchison Company, the first contractor on the Turnpike.
(Photo: Pennsylvania State Archives)

The Turnpike’s design What also made the Pennsylvania Turnpike design different was that it was considered one continuous design project from Irwin to Carlisle (the two towns that were at the original ends of the turnpike).

Charles Noble, a PTC design engineer who was later the chief engineer for the New Jersey Highway Department and the New Jersey Turnpike Authority, described this project detail in the July 1940 issue of Civil Engineering in this way: “Unlike the existing highway systems of the United States, in which design standards fluctuate every few miles, depending on the date of construction, the Turnpike will have the same design characteristics throughout its 160-mile length. Every effort has been directed towards securing uniform and consistent operating conditions for the motorist.” Noble also said, “In fact, the design was attacked from the viewpoint of motor-car operation and the human frailty of the driver, rather than from that of the difficulty of the terrain and method of construction. This policy of design, based on vehicle operation, is relatively new.”

All of the preliminary surveying and land acquisition was completed, and laborers began to pour into southern Pennsylvania nearly 54 years after construction of Vanderbilt’s railroad began.  

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)The valley between the Blue and Kittatinny mountains as it appeared on November 5, 1937.
(Photo: Pennsylvania State Archives)

Construction begins The Turnpike, its seven tunnels and more than 300 structures were under contract by July 1939; construction began one month later. Construction contracts were awarded to 155 companies from 18 states.

The project’s first concrete was poured on August 31, 1939.  By the spring of 1940, more than 15,000 workers were busy building the Turnpike. There was very little available housing along the Turnpike’s route through rural southwestern and south central Pennsylvania.

Some workers (and their families) lived in tents near the various construction sites. Hourly wages ranged from £0.525 for unskilled laborers to £1.40 for heavy equipment operators. In order to stay within the timetable set by the PWA, contractors and their crews had to work two shifts per day – and sometimes three.

Crews had to use portable generators to supply electricity to the work areas, “because little commercial electricity was available.” About £30 million of highway-building equipment was used on the project. The project’s scope was massive: 

  • 160 miles of four-lane, all-concrete highway, from Middlesex in Cumberland County (15 miles west of Harrisburg) to Irwin in Westmoreland County (20 miles east of Pittsburgh).
  • Seven two-lane tunnels totaling 6.7 miles in length. Six of the seven tunnels were former South Pennsylvania Railroad tunnels; the Allegheny Mountain tunnel was built to the south of the old railroad tunnel because it was considered unstable and dangerous.

    Tunnels were constructed at Allegheny Mountain, Ray’s Hill, Sideling Hill, Tuscarora Mountain, Kittatinny Mountain and Blue Mountain. Two other former South Pennsylvania tunnels (Quemahoning Mountain and Negro Mountain) were bypassed with open cuts.

  • Eleven interchanges, with toll booths (originally ticket offices) at Irwin, New Stanton, Donegal, Somerset, Bedford, Breezewood, Fort Littleton, Willow Hill, Blue Mountain, Carlisle and Middlesex. One toll plaza served both Carlisle and Middlesex.
  • Ten service plazas, located 25 to 30 miles apart, where travelers could purchase gasoline and food.

    The 10 service plazas cost a total of £500,000 to construct. The Commission voted not to operate the plazas, but to license them to Standard Oil of Pennsylvania, which operated the gas stations and in turn subcontracted the dining areas and gift shops to Howard Johnson’s. Copying the German autobahns, the plazas were designed to resemble regional architecture – early Pennsylvania stone houses.

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)Midway service plaza under construction.
(Photo: Pennsylvania Turnpike Commission)

Building the tunnels

The hardest task of all was completing the tunnels. None of the original South Pennsylvania Railroad tunnels that were to be used for the Turnpike had been “holed-through” in 1885. However, they had been excavated from both ends.

The uncompleted tunnel sections ranged from 551 feet in the Kittatinny Mountain Tunnel to 3,379 feet in the Sideling Hill Tunnel. Tunnel technology had changed in the intervening 55 years; there were problems because of the way that the tunnels were initially bored. While the railroad had originally planned to build double-track tunnels, financial issues arose, causing the design to be changed to single-track width tunnels.

Turnpike engineers “found wide entrances but narrow widths in the deepest parts.” Despite this issue, by utilizing the South Pennsylvania Railroad tunnels, the Turnpike saved both time and money.

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)Preliminary work inside the Tuscarora Mountain
Tunnel on January 24, 1938.
(Photo: Pennsylvania State Archives)

Construction on the tunnels was on an around-the-clock cycle. In addition to widening the tunnels to 23 feet and a height of 14 feet, the contractors were required to reinforce the walls and floors with concrete lining. They also had to build housings for the ventilating fans that would blow fresh air into the tunnels to keep carbon monoxide levels safe.

Interestingly, many of those excavating the tunnels were coal miners who had lost their jobs due to a strike against the coal companies. Clear Ridge Just east of the town of Everett was a hillside named Clear Ridge.

PTC engineers considered building a tunnel through Clear Ridge, but decided on a large cut instead. This required a massive earth-moving operation – the cut is 153-feet-deep and one-half-mile long. At that time, no highway cut that deep had ever been attempted in the United States.

PTC promoters nicknamed the cut “Little Panama,” to associate the project with the world-famous Panama Canal. While the amount of dirt removed at Clear Ridge was impressive – 1.1 million cubic yards – the amount cleared during construction of the Panama Canal was 200 million cubic yards!  To smooth out the highway’s alignment where the terrain was uneven, fill was added and compacted to avoid shifting when the concrete was poured.

Nearly 13 miles of highway was poured in 1939; however, wet weather in the spring of 1940 slowed progress. By May 8, 1940, only 30 miles of highway had been finished. However, after the weather improved 50 paving units were able to produce 2 to 3.5 miles of highway each day.

FreightWaves Classics: Pennsylvania Turnpike was first superhighway in the US (Part 1)A single-span bridge over the Turnpike near Donegal.
(Photo: Pennsylvania Turnpike Commission)

Bridges and culverts

Contractors had to also build over 300 bridges and culverts.

These ranged from 6 feet to 600 feet in length.

Single-span bridges with concrete arches were built to carry local highways over the Turnpike.