- Historic Sites
The Road To The Future
Fifty years ago the builders of the Pennsylvania Turnpike completed America’s first superhighway—and helped determine the shape of travel to come
May/june 1990 | Volume 41, Issue 4
Were the turnpike built today, it would look substantially different in some details. The 200-foot-wide right-of-way would be 300 feet wide. The median would be 60 feet wide, not 10. (Still, the fatality rate on the turnpike is one of the most favorable in the nation—0.6 deaths per hundred million vehicle-miles, less than a quarter the national average.) For greater safety, service and restaurant plazas would be set back farther from the roadway than the 1940-built plazas, as are all new or relocated plazas. The original service-plaza buildings were built of gray stone to replicate native Pennsylvania architecture, a feature too expensive to duplicate on any new one. The cloverleaf curves at interchanges would be much broader than their original 100-footradius corkscrew design; it was specifically aimed at slowing down motorists leaving the highway.
But time has hardly passed the Pennsylvania Turnpike by. Since 1987 the toll-collection system has been computerized. A segment near Philadelphia was widened to six lanes to handle the congestion resulting from commuter traffic in that area. Any realignments or bypasses are designed to current-day interstate standards, as are several route expansions under way in western Pennsylvania: the 16-mile Beaver Valley Expressway, the 13-mile Greensburg Bypass, and the Mon Valley/Fayette Expressway (which will connect Pittsburgh with Morgantown, West Virginia). All are designed to improve access and stimulate economic development in a region afflicted by the decline of steel and other durable-goods industries. A system of emergency call boxes installed every mile in the mountainous region as a trial is being expanded systemwide. Fast food has replaced the original Howard Johnson’s restaurants at the service plazas. A new seventeen-lane interchange, which will be the turnpike’s largest, is being installed near Philadelphia to provide direct connections with the last uncompleted segment of interstate highway in Pennsylvania: 1-476, the north-south “Blue Route” through the city’s western suburbs.
On the Northeastern Extension the turnpike is currently marking another first, the first American highway use of the New Austrian Tunneling Method (NATM), which the turnpike is employing to eliminate the last remaining section of the two-lane road —the Lehigh Tunnel—by boring a second two-lane tube. Used to build rail tunnels for the Washington, D.C., Metro system and the light-rail system in Pittsburgh, NATM eliminates the need to erect steel superstructures inside a tunnel after each blast and clearing of rock. With NATM, a concrete mixture known as shotcrete is sprayed on the tunnel roof and walls soon after each blast. The fast-setting solution stabilizes the rock, preventing rock falls as well as eliminating the need to assemble a supporting structure.
In Pennsylvania the tollsuperhighway concept, whose obituary has been written several times, is still alive.