Interstate Highway System

American  

[in-ter-steyt hahy-wey sis-tuhm] / ˈɪn tərˌsteɪt ˈhaɪˌweɪ ˌsɪs təm /

noun

1. Official Name Dwight D. Eisenhower National System of Interstate and Defense Highways.  a network of U.S. highways connecting the 48 conterminous states, begun in the 1950s and estimated to carry about 25 percent of the nation's traffic: also established in Alaska, Hawaii, and Puerto Rico, but without physical connections to other states or territories.

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