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. At just under 880 miles (1,420 kilometers), 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 Interstate 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. Since 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 when including feeders.

More than a third of I-10's length is located in Texas alone. El Paso, near the New Mexico state line, is 785 mi (1,263 km) from the western terminus of I-10 in Santa Monica, California, making it closer to Los Angeles than it is to Orange, Texas, 857 mi (1,379 km) away at the Louisiana state line. Likewise, Orange is only 789 mi (1,270 km) from the eastern terminus of I-10 in Jacksonville, Florida.