Yep, The SH-130 Toll Road. It is a sweet, sweet thing! I used to live in Austin, was a Taxi driver there for a quarter-century...where I picked up the moniker of The Land Yacht (google The Land Yacht Austin some time & look for the big rollin yellow beast that was a taxi).
Actually, have a LINK
The 41-mile (66 km) section of the toll road between SH 45 and I-10 is noteworthy for having a posted speed limit of 85 mph (137 km/h), the highest posted speed limit in the Americas. As of September 2012, the only speed limits in the world higher than this are the 140 km/h (87 mph) limits of Poland, Bulgaria and Abu Dhabi,[2] though some jurisdictions like Germany and Isle of Man have roads without any posted maximum limit.[3][4]