The Rise of the Divided Highway in America, 1920s the WWII.

There is a 13-mile stretch of the Turnpike, with three tunnels and a travel plaza, east of the Breezewood area, that was bypassed in 1968 and dubbed "The Abandoned Pennsylvania Turnpike." 

PA Turnpike: the Highway of Tunnels

Divided Highways, Parkways, and Expressways

            One such innovator was Englishman Hilare Belloc, who in 1924 wrote a book entitled The Road. Belloc proposed great arterial roads joining main population centers that were to be wide, as straight as possible, with no intersections at grade, and finally having limited access. In a chapter entitled “The Future” Belloc stated that

A very few great arterial roads joining the main centers of population would have far more effect upon our present difficulties than their mere mileage would seem to warrant. There could be no question of stopping the new form of traffic upon ordinary roads remaining, which might be twenty or fifty times those of the new roads. But it would be of such advantage for long-distance travel to use the great arteries that at the expenditure of greater mileage you would find the new traffic seeking them at the nearest point upon one side and clinging to them for as long as possible.³⁵

            Essentially, Belloc was envisioning the modern expressway, as were a few of his contemporaries such as Arthur Hale, who patented the cloverleaf in 1916.

            These kind of roads were built in Mussolini’s Italy during the 1920s (the autostrade) and in Hitler’s Germany of the 1930s (the autobahnen).³⁶ Adolf Hitler’s highways were dramatically innovative roads that were perhaps the most publicized and visible products of the new regime. They have also proved to be the most enduring of the Third Reich’s material legacies, still carrying traffic, and thus promising to fulfill Hitler’s boast that “the construction of these roads will give the German people traffic routes for the most distant future.” The autobahnen were critical to Hitler’s plan for the mass motorization of Germany, first announced at the Berlin auto show of 1933. Between 1933 and 1936 auto production increased five times. These roads were also important aspects of Hitler’s plan eliminate unemployment; by 1936 some 130,000 men were employed directly and 270,000 indirectly in industries like cement mixing and stone masonry. Construction workers, living under a military-like regimen, were housed in isolated camps near the work sites.

            The autobahns of the 1930s amounted to beautiful works of civil engineering. They blended organically into the landscape; it was said that those who constructed them had a real concern for the environment. Autobahns were built not to disturb scenery and landscape unnecessarily, and they were designed to contribute to the driver’s appreciation of the natural surroundings.

            Even though most work went into conventional road building during the Depression years, the seed of the expressway system was sown at that time. Although federal funds went into 2-lane projects, ironically perhaps, local funds were for the most part used to design high-speed motor traffic highways. This was especially true in Connecticut, with the opening of the Merritt and Wilbur Cross Parkways. In Pennsylvania, where in 1937 a Turnpike Commission was created to build a toll road using an old railroad right of way, a mix of federal and state funds were allocated.

            Some federal funds came from the Public Works Administration (PWA), and surveys had actually begun in 1936. Features of the new road included four 12-foot wide lanes, a 10-foot wide median strip and 10‑foot side berms, and a limited access with 1,200 foot entrance and exit lanes. On October 13, 1940, 160 miles of turnpike between Carlisle (West of Harrisburg) and Irwin (east of Pittsburgh) was opened. It soon became the preferred way of truck traffic, since 7 tunnels were used, the grade on the Pennsylvania turnpike had been restricted to 3 percent and thus fuel consumption was decreased considerably. Finally, the driving time between Harrisburg and Pittsburgh was cut from five and one-half hours to two and one-half. Initially, the Pennsylvania turnpike had no speed limits, but in April 1941 a 70 mph limit was set, although in tunnels one had to maintain a speed of 35 mph.

            As successful as the Pennsylvania Turnpike became, across the country in Los Angeles similar developments were taking place that proved to be equally as successful. Lloyd Aldrich, who became Los Angeles city engineer in 1933, became a principal champion of the freeway, and he was one of the first to perceive an essential element for a modern metropolis; namely, that the time required to complete the journey was far more important than the distance covered. In 1940 under Aldrich’s direction the Pasadena freeway was completed, the first link in a proposed 300 mile web of urban freeway.

            The first of the LA freeways was named the Arroyo Seco Parkway. This road had no number designation, and originally the speed limit was 45 miles per hour. With two lanes of traffic in each direction and a broad shoulder for emergencies, the route ran from downtown Los Angeles to Pasadena. At the time, it was considered an engineering marvel, although it is obsolete by today’s standards. Indeed, most current-day drivers would consider the road dangerous; merging is almost immediate and right shoulders are narrow. Despite the fact that one must often stop before gaining access, it is a heavily-used thoroughfare, with 3 three lanes in each direction.

            Thus, on the eve of World War II, America had taken critical steps in highway construction that would be instrumental to the explosion of interstate highways beginning in the 1950s. Regions were now linked together, tourism was now a part of middle-class life, and trucks were moving an increasing percentage of manufactured goods and agricultural produce.