State Highway 99 (Grand Parkway) is a proposed 180+ mile circumferential scenic highway traversing seven counties and encircling the Greater Houston region. The project has been shown on governmental planning documents since the early 1960's.

Currently 20 miles of the highway, Segment D, from US 59 near Sugar Land to IH 10 near Katy, have been constructed and is a toll free road open to the traveling public since August 31, 1994.

On February 19, 2008, a ribbon-cutting celebration commemorating the completion of the first phase of Segment I-2 (IH 10 to FM 1405) was held, and the segment was opened to traffic on March 25, 2008. Phase 2 of Segment I-2 (FM 1405 to SH 146) is currently under design.

Other segments are in various stages of project development. For detailed segment information, please click on the segment's tab to the left.