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 over , 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, a title formerly held by
Ontario Highway 401. 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 between Houston and East Texas 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.