Pan-American Highway
The Pan-American Highway is a network of roads stretching across the American continents and measuring about in total length. Except for a rainforest break of approximately , called the Darién Gap, the roads link almost all of the Pacific coastal countries of the Americas in a connected highway system. According to "Guinness World Records", the Pan-American Highway is the world's longest "motorable road". However, because of the Darién Gap, it is not possible to cross between South America and Central America with conventional highway vehicles. Without an all-terrain vehicle, it is necessary to circumnavigate this terrestrial stretch by sea.
U.S. Route 6
U.S. Route 6 (US 6), also called the Grand Army of the Republic Highway, honoring the American Civil War veterans association, is a main route of the U.S. Highway system. While it currently runs east-northeast from Bishop, California to Provincetown, Massachusetts, the route has been modified several times. The highway's longest-lasting routing, from 1936 to 1964, had its western terminus at Long Beach, California. During this time, US 6 was the longest highway in the country.