State Highway 99, also known as the Grand Parkway, is a partial beltway in the U.S. state of Texas. Its first section opened on August 31, 1994. If the route is completed, it will be the longest beltway in the U.S., the world's eighth-longest metropolitan ring road, and the third (outer) loop of the Houston–The Woodlands–Sugar Land metropolitan area, with Interstate 610 being the first (inner) loop and Beltway 8 being the second (middle) loop. The proposed 176.6-mile (284.2 km) loop has been divided into 11 separate segments for construction and funding purposes. In May 2019, the Texas Department of Transportation gave the Grand Parkway a secondary designation as the Mayor Bob Lanier Memorial Parkway, honoring Bob Lanier, who served as the mayor of Houston from 1992 to 1998 and who had spearheaded the creation of the Grand Parkway.