Other achievements in interstate construction are closely associated with the 'Not In My Backyard' movement. Many urban areas have 'gone green' in recent decades, improving their routes to meet increased environmental concerns and the aesthetic needs of citizens; some projects were even forced to halt construction entirely until such concerns were addressed in advance. Worries about the safety of the endangered and much beloved Florida panther led to the construction of special underpasses along Alligator Alley, the portion of I-75 that connects Naples and Miami in Florida, allowing panthers and other wildlife to cross safely beneath the flow of traffic. One section of I-10 in Arizona that opened in 1990, the Papago Freeway, runs beneath '19 side-by-side bridges that form the foundation for a 12-hectare [29.6 acre] urban park,' according to Richard F. Weingroff, a former official at the Federal Highway Administration. Known as the Margaret T. Hance Park, the space was conceived as a unique solution to the vexing problem of how to maintain connections between neighborhoods divided by the interstate. In other areas, simpler concerns required simpler solutions, such as tree-lined medians, noise-reducing berms and walls, lowered speed limits and prohibitions against large trucks.
Flanked by access roads, I-35 is constructed to cut a swath through Austin, Texas. (National Archives)
A frequent complaint leveled against the NHDS is that it has stripped the adventure and romanticism from long-distance traveling. Upon the completion of I-40 (Barstow, Calif., to Wilmington, N.C.), the late CBS News commentator Charles Kuralt observed: 'It is now possible to travel from coast to coast without seeing anything. From the Interstate, America is all steel guardrails and plastic signs, and every place looks and feels and sounds and smells like every other place.' While the criticism is to an extent justified, it is also true that the NHDS directly serves nearly every major metropolitan area (as well as countless smaller areas of population) and is home to, or otherwise conveniently located near, thousands of tourist destinations across the country.
Some of the most intriguing and impressive tourist stops are those that are not content to simply nestle alongside the highway, but those that, like the Great Platte River Road Archway Monument, literally straddle it. The Archway Monument, a 1,500-ton structure spanning 308 feet acrossI-80 in Kearney, Neb., is a celebration of frontier culture designed to resemble a covered bridge. Built to honor the thousands of pioneers who had followed the arduous route from Missouri to the West Coast during the 19th century, the Archway Monument is a living bridge to history over a modern river of asphalt, a testament to the wisdom of and need for well-planned, well-constructed infrastructure. Eisenhower would have approved of the symbolism.
Whatever else these features may be in and of themselves, they are ultimately incidental to the system's much more vital main purpose. The NHDS, according to a 1996 report written by Wendell Cox and Jean Love 40 years after Eisenhower signed the Federal-Aid Highway Act of 1956, was conceived and marketed as the best possible way to facilitate 'the quick and efficient movement of military equipment and personnel' in the event of a Soviet invasion or nuclear strike. Inspired by the autobahn, Eisenhower envisioned multilane highways â€” 'broader ribbons across the land,' as he called them â€” yet even at its narrowest points, the system can still accommodate all but the most cumbersome wheeled or tracked military vehicles. Also, most military bases are situated within close proximity to the NHDS, adding to the already unequaled in-country response capability of the U.S. armed forces â€” a fact that is every bit as comforting as the fact that there has never been occasion to use this capability to its utmost.
One widely held dual-use-related belief is that one out of every five miles of the NHDS is mandated to be straight and level, capable of functioning as an emergency airstrip. Aside from the fact that, according to Weingroff, 'no law, regulation, policy, or sliver of red tape requires that one out of every five miles of the interstate highway system be straight,' it is virtually impossible from an engineering standpoint. The NHDS is composed of nearly 50,000 miles of road, meaning that almost 10,000 miles would need to be straight and level to conform to the supposed one-in-five-mile rule, a figure that is wildly unrealistic. In addition, from an aerial standpoint, an airstrip every five miles is superfluous, given the speed at which modern aircraft travel. Although there are long and level stretches of highway that could function as an emergency landing strip in a pinch, they are nowhere near as evenly parceled out as the one-in-five-mile rule would suggest. (The use of highway infrastructure for an airstrip is not unheard of, however: Nazi Germany did use limited stretches of the autobahn for such purposes during World War II.)
One cannot discuss the NHDS without also mentioning its impact on the U.S. economy. It is, quite literally, the economic engine that drives this country's prosperity. No other industrialized nation has such a sprawling and comprehensive system of roadways, though many are now seeking to emulate the U.S. model as a means toward becoming more competitive in the international marketplace. One look at the figures in the Cox and Love report and it is not hard to understand why. By 1996 the interstates, comprising just over 1 percent of the miles of public road in this country, carried 'nearly one-quarter of the nation's surface passenger transport and 45 percent of motor freight transport.' During the course of its first 40 years, the system was responsible for an increase of 'approximately one-quarter of the nation's productivity.' Highway transportation and directly related industries accounted for more than 7 million jobs.
Indirectly related industries have felt the uptick, as well. In the restaurant business alone, employment 'has increased more than seven times the rate of population growth,' according to the Cox and Love report. By making '`just in time' delivery more feasible' while simultaneously reducing tractor-trailer operating costs by as much as 17 percent compared with other roadways, the NHDS has played a major role in making the electronic marketplace a workable phenomenon for all parties involved: retailers, delivery companies and consumers alike. Perhaps the most telling figure is the return rate of $6 for every $1 spent on highway construction. Consider also that in the 10 years since those figures were generated, several factors â€” population expansion, the advent of e-commerce, our national reluctance to fly following the terrorist attacks of September 11, 2001 â€” have conspired to place an even greater share of traffic onto our nation's highways. The many differences separating 2006 from 1996 notwithstanding, the conclusion of the Cox and Love report concerning the economic impact of the NHDS remains as true today as the day it was written: 'By improving inter-regional access, the interstate highway system has helped to create a genuinely national domestic market with companies able to supply their products to much larger geographical areas, and less expensively.'
For most of us, though, the dual-use military features and the economic benefits of the NHDS are barely an afterthought. The interstate is a way to get to work, to go downtown, to shave 30 minutes off the drive to grandma's house. Often it is the backbone of that uniquely American pastime, the road trip. Sometimes it's just a headache. Occasionally it becomes a lifeline out of harm's way.
In 1990 the National Highway Defense System was renamed the Dwight David Eisenhower National System of Interstate and Defense Highways under an act of Congress signed into law by President George H.W. Bush. As tributes go, it was perfectly appropriate. 'Of all his domestic programs,' Ambrose wrote, 'Eisenhower's favorite by far was the Interstate System.'
For all its detractors' criticism, the interstate system, more than any other project in the past 50 years, has encouraged an unprecedented democratization of mobility. It has opened up access to an array of goods and services previously unavailable to many and created massive opportunities for five decades and three generations of Americans. It has made the country more accessible to itself while also making it safer and more secure, outcomes that in almost any other undertaking would prove mutually exclusive. 'More than any single action by the government since the end of the war, this one would change the face of America,' Eisenhower wrote in 1963. 'Its impact on the American economy â€” the jobs it would produce in manufacturing and construction, the rural areas it would open up â€” was beyond calculation.' The clarity of his vision and the resiliency of his words are inarguable. The Eisenhower Interstate System has grown to be valuable beyond its original intent and is a lasting tribute to American ingenuity, ability and strength of purpose.