The efforts of the United States to design and build a national highway network began rather haphazardly with the passage of the Federal Aid Road Act of 1916. The Act allowed the provision of $75 million spread out over course of five years for matching funding to each state to create and maintain a national highway system. However, the onset of WWI in 1918 preempted any other funding for this policy. The provision expired in 1921.
In 1918, civil engineer and Engineering News-Record editor E.J. Mehren suggested a highway construction plan to the State Highway Officials and Highway Industries Association, the members of which were taking part in a meeting at the Congress Hotel in Chicago. Mehren suggested the creation of a 50,000-mile road system that included five east-west routes and 10 north-south routes. The system would comprise a total of two percent of all roads in the United States and would link each state. The cost of the project was estimated at $25,000 per mile and would help boost commercial transportation as well as improve military mobility.
As the result of Mehren’s suggestion, the Federal Aid Highway Act was passed in 1921. This law, also known as the Phipps Act, provided for matching federal funding to the states for construction and improvement of the road systems. For the first time in U.S. history, the legislation targeted these funds toward the construction of a national highway grid of interconnected primary highways. The Army provided a list of roads considered necessary for national defense to ensure that the system would benefit the country in the event of an attack or an emergency. With that, the National Highway System of America was born.
The National Highway System of the United States is composed of a network of interstate highways and other road ways leading to major cities, ports, terminals and other strategic facilities. This system is the largest of its kind in the world and plays a huge role in making the United States a leading nation. The National Highway System Designation Act was signed into law in 1995 by President Bill Clinton. The act designated which roads were to be part of the NHS and listed approximately 161,000 miles of roadways, including the Interstate Highway System.
The Interstate Highway System is also known as the Dwight D. Eisenhower National System of Interstate and Defense Highways and was named after the WWII general and United States president Dwight Eisenhower. The construction of the system was approved by the Federal Aid Highway Act of 1956. Thirty-five years later, the original roadways were completed. Some routes, however, were never built and were cancelled before they became part of the system. The network has since been extended and had a total length of approximately 48,000 miles in 2016. Around 25 percent of all vehicle miles across the U.S. are driven on the interstate system.