A series of highways knot this fish-eye aerial view of downtown Los Angeles, California.

Photograph by Bruce Dale, National Geographic

Oh no! It appears that there was an error with your submission. Care to try again?

Coming soon!

You've found a feature that is not available.

Get notified when this feature is available

  • On July 11, 1916, U.S. President Woodrow Wilson signed the Federal Aid Road Act. This law made federal money available for creating and maintaining highways. Up until this time, the cost for building and maintaining roads had been either a state or local responsibility. Many roads were unpaved, and in very bad condition. The act led to a dramatically improved infrastructure in the United States.

    Improvements to the road system coincided with the introduction of affordable cars. This meant many more Americans were driving, and driving longer distances, than ever before. Within a year, every state had a chapter to administer the federal highway funding. Over the next 50 years, roads would continue to improve and expand, giving rise to suburban life and the interstate highway system. Today, the United States transit system has 6.3 million kilometers (3.9 million miles) of public roads.

  • Term Part of Speech Definition Encyclopedic Entry
    administer Verb

    to manage or supervise.

    coincide Verb

    to occur at the same time.

    expand Verb

    to grow or get larger.

    federal Adjective

    having to do with a nation's government (as opposed to local or regional government).

    highway Noun

    large public road.

    improve Verb

    to make something more valuable.

    infrastructure Noun

    structures and facilities necessary for the functioning of a society, such as roads.

    interstate roadway Noun

    numbered road that stretches between at least two U.S. states. Also called "I" followed by the roadway's number.

    transit Noun

    event when a planet passes between a viewer and the sun.