The 47,000 miles of
highways that comprise America’s interstate highway system are nothing short of
an engineering marvel, surpassed only by what China
has built in the last few years.
We take them for
granted, but when they were designed almost sixty years ago these
super-highways presented both great opportunity and vast challenges. The US wasn’t the first with super-highways.
Those bragging rights go to the Germans, whose Reichsautobahn
saw cars zooming along at 100+ mph in the 1930’s.
Most credit President
Eisenhower, whose troops rode the Autobahn in WWII, for seeing the military
value of an American equivalent, though engineering such a complex across the
US was far more difficult.
Of course by 1940
the US already had the Pennsylvania Turnpike and by 1954 the NY State Thruway,
but private toll roads were just the beginning.
To build a road
expected to last, in 1955 the federal government, AAA and automakers first built
a $27 million seven mile test road near Ottawa, Illinois. Half was concrete, the other half
asphalt. The 836 separate sections of
highway had various sub-surfaces and 16 bridges. For two years army trucks drove night and
day, seeing which road designs would hold up.
Weather and traffic
dictated different designs: in desert
areas the highways need be only a foot thick, while in Maine the tough winter
and freeze-thaw cycles required that I-95 would be five feet thick.
Construction of the
highways required moving 42 billion cubic feet of soil. To expedite construction of I-40 in
California, there was even a plan to use nuclear bombs to vaporize part of the
Bristol Mountain range.
As author Dan
McNichol writes in his excellent book “The
Roads that Built America”, “VIP seating was even planned for
the event. The (nuclear) bombing was to
produce a cloud 12,000 feet high and a radioactive blast 133 times that of
Hiroshima.” Needless to say, the
mountains were moved using more conventional explosives.
Outside of
Greenbelt MD another site tested the design of road signs… white lettering on a
black background, white on blue (already adopted by the NY Thruway) or, what
proved to be the winning model, white on green.
Just 5200 of the
original 41,000 miles of Interstates were to be built in urban areas, but those
few miles accounted for almost half of the $425 billion total cost. By 1992 the system was deemed
“completed”. Bragging rights for the
longest of the interstates goes to I-90 running 3020 miles from Boston to
Seattle and own beloved I-95, which runs 1920 miles from the Canadian border to
Miami FL.
As anyone who
drives on I-95 in Connecticut knows, the interstates have far surpassed their expected
traffic load and are in need of billions of repairs. Little did we know 60 years ago what our
automotive future might bring.
