State Highway 99, also known as the Grand Parkway, is a Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 highway

Highway

A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a...

, which opened its first section in 1994. When State Highway 99 is complete, it will be the longest beltway in the world, and the third loop within the Houston–Sugar Land–Baytown

Greater Houston

Houston–Sugar Land–Baytown is a 10-county metropolitan area defined by the Office of Management and Budget. It is located along the Gulf Coast region in the U.S. state of Texas...

 metropolitan area, with Interstate 610

Interstate 610 (Texas)

Interstate 610 is a freeway that forms a forty-two-mile loop around the downtown sector of city of Houston, Texas. Interstate 610, colloquially known as "The Loop", "Loop 610", "The 610 Loop", or just "610", traditionally marks the border between the inner city of Houston and its surrounding areas...

 being the inner loop, and Beltway 8 (Sam Houston Tollway) being the middle loop. The proposed 170 miles (273.6 km) loop has been divided into 11 separate segments for construction and funding purposes.