From the Texas Department of Transportation:
EAST TEXAS - About 118 miles of highways in rural Northeast Texas will have their speed limits increased from 70 to 75 miles per hour this week as the contractor installs the new signs making the speed limit official.
The Texas Transportation Commission approved the increased speed limits in December following a year-long engineering and speed study for highways with speed limits already at 70 mph. The 82nd Texas Legislature passed and the Governor signed House Bill 1353 which allows the Texas Department of Transportation (TxDOT) to establish 75 mph speed limits on Texas highways providing speed studies show it can be done safely.
Speed limits on most rural interstate highways in the state were increased to 75 mph last year.