Pennsylvania Turnpike (thing)

Taken from Pennsylvania Highways, by Jeff Kitsko (used with permission from the author - thanks Jeff):

This highway should have no introduction, since it is "America's First Superhighway." However, the Turnpike had its roots in another form of transportation: the railroad. William H. Vanderbilt proposed an idea to build a railroad from Harrisburg to Pittsburgh that would be under his control, and not that of the Pennsylvania Railroad.

After the surveying was complete, work began on a two-track roadbed with nine tunnels. Excavation began on the tunnels in early 1884. Thousands of workers dug the tunnels for $1.25 for a 10 hour day. The construction continued through 1884 and 1885; however, trouble for the project was starting in New York. Banker J. Pierpont Morgan won a seat on the board of Vanderbilt's New York City & Hudson River Railroad. Morgan with the President of the NYC&RRRR sold the right-of-way to George B. Roberts, President of the Pennsylvania Railroad. Work stopped immediately. A total of $10 million had been spent and 26 workers lost their lives. The unfinished project came to be known as "Vanderbilt's Folly"...

The twentieth century came and with it a new form of transportation: the automobile. Pennsylvania was one of the first states to establish a highway department. In late 1934, an employee with the State Planning Board named Victor Lecoq and William Sutherland of the Pennsylvania Motor Truck Association proposed the idea of building a toll road utilizing the old roadbed and tunnels left behind. With these two gentlemen and with newly elected Representative Cliff S. Patterson, the idea became reality. On April 23, 1935, he introduced House Resolution #138 to authorize a feasibility study...

The engineers also had to change they way they designed highways. Highways had always been built with flat curves to discourage speeding. Now, the engineers were expected to design easy grades, to allow cars and trucks year round use. Long, sweeping curves would give ample room for high speeds and safe stopping distances. The engineers decided on the following standards:

• 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 of 78 foot width of ROW. (Early plans called for 10 foot wide lanes, and just a four foot wide median strip. Also, a cheaper design that used two concrete lanes and two asphalt lanes was dropped.)
• A maximum grade of 3 % (three feet of climb for every 100 feet of forward travel), compared to hills as steep as 9 to 12 % on the old two lane William Penn (US 22) and Lincoln Highways (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 superelevation, or banking, on curves.
• Limited access, with 1,200 foot long entrance and exit ramps to provide plenty of distance for accelerating and decelerating.
• 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.

What separated this highway from others was that it was considered one continuous design task from Irwin to Carlisle. Charles Noble, a design engineer for the Commission who later moved on to become chief engineer for the New Jersey Highway Department and the New Jersey Turnpike Authority, described this feat in the July 1940 Civil Engineering magazine, "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." He also went on to say, "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"...

The project called for:

...

The full text of this article can be found at http://www.pahighways.com/toll/PATurnpike.html

From the official Pennsylvania Turnpike website (http://www.paturnpike.com), the Turnpike was later expanded as follows:

• Philadelphia Extension, Carlisle (Exit 16) to Valley Forge (Exit 24); 100 miles, opened 1950.
• Western Extension, Irwin (Exit 7) to Ohio line (Exit 1); 67 miles, opened 1951.
• Delaware River Extension, Valley Forge to Delaware River (exit 30); 33 miles, opened 1954.
• Delaware River Bridge Interchange to Bridge; 1.5 miles, opened 1956.
• Northeastern Extension, Main Line to Scranton (Exit 39); 110 miles, opened 1957.
• James J. Manderino Highway (Turnpike 43), opened 1990.
• James E. Ross Highway (Turnpike 60), opened 1992.
• Amos K. Hutchinson Bypass (Turnpike 66), opened 1993
• Mon-Fayette Expressway/Mason-Dixon Link, opened 2000

The Pennsylvania Turnpike has a total of eight tunnels: Allegheny, Laurel Hill, Ray's Hill, Sideling Hill, Tuscarora Mountain, Kittatiny Mountain, Blue Mountain, and Lehigh. Of these, the Laurel Hill, Ray's Hill, and Sideling Hill tunnels have been bypassed. Blue Mountain and Lehigh tunnels cut through the same mountain.

Even though it's not completely up to standard (simply because of the narrow median), the Turnpike is currently signed as Interstate 76 through most of its length (I-76 continues on the Schuylkill Expressway towards Philadelphia), and as I-276 from Valley Forge to the Delaware River Bridge. The Northeast Extension is signed as I-476 (which it shares with the Blue Route), from its previous designation as PA-9.