Texas State Highway 99

Segment A would extend from SH 146 near San Leon to I-45 in League City. As of November 2022, it is not considered a viable project.[10]

Segment B will extend from I-45 in League City to SH 288 near Rosharon. In mid-October 2023, TxDOT announced that it would begin construction on Segment B-1, which will connect I-45 to SH 35 in Alvin, in Spring 2027 with it completion set for 2030. Open houses on the project were requested during this part of the month as well.[11]

Segment C will extend from SH 288 near Rosharon to I-69/US 59 in Sugar Land.[13] As of January 2022, its estimated completion date is to be determined.[14] Construction was originally scheduled to begin in August 2016, but the plans were re-evaluated and re-approved on March 9, 2017.[13]

Segment D, the first section opened, runs from just north of I-10/US 90, west of Houston, south to I-69/US 59 in Sugar Land, where it terminates and intersects with FM 2759. The portion of this segment south of the interchange with the Westpark Tollway is now a four-lane divided highway feeder road, with mainlanes crossing over the Westpark Tollway.

The 18-month-long construction of two ramps connecting westbound I-10/US 90 to southbound SH 99 and northbound SH 99 to eastbound I-10/US 90 was completed in 2011. The occasional traffic jams at this intersection prompted the sped-up construction of the ramps before the through lanes of SH 99 were built through the I-10/US 90 interchange. Two more ramps connecting southbound SH 99 to eastbound I-10/US 90 and westbound I-10/US 90 to northbound SH 99 opened as part of the construction of Segment E in December 2013. A final ramp connecting northbound SH 99 to westbound I-10/US 90 has been completed and is operational.

Between the Westpark Tollway and I-69/US 59, Fort Bend County has constructed toll overpasses at nine locations along SH 99. Overpasses between I-69/US 59 and US 90 Alternate opened on February 27, 2014, Airport Boulevard and Harlem Road on March 18, 2014, and Mason Road and Bellfort Street on March 30, 2014. The remainder of the tolled overpasses to I-10/US 90 opened in late April 2014.[15] Motorists in 2-axle vehicles may pay between $0.46 and $0.69 to use each overpass, or they may bypass the toll by using the current roadway through the signalized intersections.[16]

A TxDOT study is currently underway for Segment D.[17] The study includes looking at ways to reduce traffic in the original segment of the non-tolled portion of the freeway; this includes the possibility of adding continuous frontage roads. This segment has been open since 1994 and population, and thus traffic, in the surrounding area has increased greatly since. There is no timetable on when or if any new projects will come out of this study.

Segment E connects I-10/US 90 Katy Freeway in the south near Katy to US 290/SH 6 near Cypress. Construction began in summer 2011,[18] and Segment E opened as scheduled in December 2013.[19]

On June 3, 2008, the Harris County Commissioners Court voted to fast-track the construction of Segment E, with construction to begin in 2009. Despite the addition of $150 million in stimulus funding, the project stalled. As with many stimulus-funded projects, the construction of Segment E turned out not to be "shovel ready" enough, and the funds were sent back to TxDOT for use elsewhere.[20] In 2011, the Wetlands permit from the Army Corps of Engineers was acquired. In addition, Harris County relinquished its rights to TxDOT so that the latter could construct a public–private cooperative toll road. At its meeting on April 28, 2011, TxDOT allocated $350 million, and the construction permits were let in July 2011.[20] On July 28, 2011, TxDOT reported that three out of four contracts for Segment E were awarded and that construction would start by early September 2011.[21]

The multi-year reconstruction of I-10/US 90 was completed in 2008, while US 290/SH 6 reconstruction was not scheduled to begin until 2011.[22] The 22-mile (35 km) section of I-10/US 90 from Katy to just inside the I-610 loop was expanded to handle the rapidly-growing western suburbs with additional mainlanes and two high-occupancy toll lanes.

Segment F-1 connects US 290/SH 6 near Cypress to SH 249 near Tomball. Construction began in June 2013 and was completed and opened to traffic on February 5, 2016.[23][24] In early 2020, construction commenced on four direct connectors: two from northbound Tomball Tollway to east and westbound Grand Parkway, and two connecting to southbound Tomball Tollway from east and westbound Grand Parkway. The project is scheduled for completion in 2022.[25]

Segment F-2 connects SH 249 near Tomball with I-45 near Spring. Construction began on Segment F-2 in June 2013. A one-mile section of frontage road lanes between I-45 and Holzwarth Road (near the ExxonMobil Campus in Spring) was completed and opened to traffic in April 2015. The remainder of Segment F-2 opened on February 5, 2016.[26][24]

Segment G connects I-45 near Spring with I-69/US 59 in New Caney. Construction began in June 2013 and was completed and opened to traffic on March 29, 2016. An interchange with the Hardy Toll Road was completed on July 18, 2016.[20][23][27]

Segments H and I-1 extend from I-69/US 59 north of Houston to I-10. Texas Transportation Commission members met in Pasadena in late June 2015, and one item on their agenda is soliciting interested builders to develop, build and maintain the next 37.4 mi (60.2 km) Grand Parkway segment from I-69/US 59 north of Houston to I-10 east of the city. The project, which began construction in the summer of 2017,[28] was expected to cost $1.2 billion. Due to Hurricane Harvey, the completion date was delayed from 2019 to May 2022, when it opened.

The southern end of the tolled portion of segment I-2

Segment I-2, which opened on March 25, 2008, after five years of construction, runs from I-10 east of Houston south to Business SH 146 in Baytown. (The former Spur 55, which ran from FM 1405 to Business 146, was renumbered SH 99 and connects with the newly constructed portion of Segment I-2 at FM 1405.) TxDOT began collecting tolls on this segment on November 1, 2011.