U.S. Route 20
U.S. Highway 20 (US 20) is an east–west United States highway that stretches from the Pacific Northwest all the way to New England. The "0" in its route number indicates that US 20 is a coast-to-coast route. Spanning , it is the longest road in the United States, and particularly from Newport, Oregon to Boston, Massachusetts, the route is roughly parallel to that of the newer Interstate 90 (I-90), which is in turn the longest Interstate Highway in the U.S. There is a discontinuity in the official designation of US 20 through Yellowstone National Park, with unnumbered roads used to traverse the park.
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.