Freeway

The advent and eventual domination of the automobile created a corresponding demand for roads capable of handling the increasing traffic and loads. Increasing numbers of cars began to choke the cities with traffic. The need for linking cities to one another also became apparent, especially as the truck proved its flexibility and reliability for transporting goods, materials, and products.

The freeway was first conceived as a means for reducing the crush of traffic within the cities, and for linking the cities together. The first freeway was opened in the Grunewald Forest in Berlin, Germany, in 1921. The idea for a national highway system for the United States was also developed during this time. The first United States freeways appeared in 1940, when California opened the Arroyo Seco Parkway between Pasadena and Los Angeles, and when Pennsylvania opened the first section of the Pennsylvania Turnpike.

The numbers of automobiles in use skyrocketed in the years after the World War II. With this increase came an alarming increase in traffic congestion and automobile accident fatalities. In 1956, legislation was passed creating the Federal Interstate Highway System (FIHS). This network of freeways was meant to link nearly all cities in the United States with populations greater than 50,000 people. Although the original plans called for exactly 40,000 mi (64,630 m) of road, by the 1990s nearly 45,000 mi (72,405 m) of road surface had been completed, carrying more than 20% of all traffic in this country. Freeways in the FIHS are constructed according to strict guidelines governing the materials and other elements of their design and construction.

Freeways dramatically changed the pattern of life in the United States. Access to the city by automobile allowed people to move beyond the traditional trolley and horse-drawn cart routes. The spread of people outside of the city created what is known as urban sprawl, in which the city extends farther and farther from its center. Meanwhile, the former centers of city life lost more and more manufacturers and other industries to the suburbs, draining the cities of vital resources and jobs. Although the freeway was originally meant to alleviate traffic, it actually increased traffic levels, by encouraging the use of the automobile over mass transportation methods such as trains and buses. The resulting increases in congestion brought problems of pollution and noise. What were once "walking cities" were now accessible only by car. Entire new communities, the suburbs, became so dependent on automobiles that most families found it necessary to have two or more. Meanwhile, the increased traffic on the roads brought corresponding increases in the number of traffic fatalities.

Nonetheless, the FIHS remains the most ambitious public works undertaking in American history. The FIHS has made nearly every part of the country accessible by car. It has brought a greater flexibility and choice of places for people to live, work, and travel, and a greater mobility over longer distances and safer roads.