The abandoned tunnel at Sideling Hill, the longest of the original tunnels on the Pennsylvania Turnpike, is more than a mile and a quarter long. Nine workers were killed during the blasting for the tunnel in 1886. Since there are no lights in the tunnel, the photograph was shot with the camera on a tripod using a 30-second exposure. (Photo by Mark Pynes)

Tunnel vision

Will engineering marvel of yesteryear hold up to demands of today's high-speed traffic?

To begin with, the road was unlike anything most drivers had ever encountered in the United States: Four lanes of superhighway cutting from just west of Harrisburg to just east of Pittsburgh - straight, level and true. A road that for the first time in Pennsylvania history would bend the earth to its needs rather than the other way around, cutting travel time between the two cities by more than six hours.

Less than eight years earlier the state had embarked upon its first massive road-paving program - sold by then Gov. Gifford Pinchot as a means to "get the farmer out of the mud." Some of the men, and not just the old gaffers, who built the turnpike could remember when a road project simply entailed farmers dragging logs with horse teams to smooth the muddy ruts in the road by their homesteads.

The idea of the highway itself - a giant public works project to employ tens of thousands of men amid the Depression - was so far-fetched that opponents said it couldn't be completed, much less in the single year of construction called for in the project's timeline.

One hundred and sixty miles would have to be paved, 114 bridges built and seven tunnels blasted and bored through the Appalachian Mountains that had, until then, blocked the easy westward passage of man and mule. The work would be done amid labor fights, tunnel collapses, a hellish winter and ongoing legal disputes over the road's right-of-way.

» Related: How to find the abandoned tunnels of the Pa. Turnpike

Yet, on Oct. 1, 1940, slightly more than a year after construction began, the Pennsylvania Turnpike's gates lifted for the first time, and cars and trucks - some of which had lined up a day before to be the first on the new highway - rolled onto history.

Newspaper accounts went to pains to explain the concept of the turnpike and its "interchanges" and "overpasses" to drivers who had, until now, only encountered at-grade intersections when driving.

"From the standpoint of the motorist, the Highway will have everything modern engineering can offer," said the lead story in the next day's Somerset Daily American. "Speeds up to 105 miles-per-hour have already been attempted on the highway..."

It was a modern marvel, which pundits of the time compared to the pyramids in Egypt or the Great Wall in China. Seven two-lane tunnels would direct traffic not around the mountains but straight through them at 55 mph.