What's the longest highway in the world?
Pan-American Highway
The Pan-American Highway[1] is a network of roads stretching across the American continents and measuring about 30,000 kilometres (19,000mi)[2] in total length. Except for a rainforest break of approximately 160km (100mi), 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.
Interstate 10 in Texas
Interstate 10 (I-10) is the major east–west Interstate Highway in the Southern United States. In the U.S. state of Texas, it runs east from Anthony, at the border with New Mexico, through El Paso, San Antonio and Houston to the border with Louisiana in Orange, Texas. At just under , the Texas segment of I-10, maintained by the Texas Department of Transportation, is the longest continuous untolled freeway in North America that is operated by a single authority. It is also the longest stretch of highway with a single designation within a single state. Mile marker 880 and its corresponding exit number in Orange, Texas, are the highest numbered mile marker and exit on any freeway in North America. After widening was completed in 2008, a portion of the highway west of Houston is now also believed to be the widest in the world, at 26 lanes. There is a wider section in China on the G4 Beijing–Hong Kong–Macau Expressway; however, that section is a toll plaza approach.