[Wallace T.]

If the Feds or the State holds speed limits on the Trans-Texas Tollway to 70 or 75 mph, the highway will be unsuccessful. The Trans-Texas Tollway starts out with several disadvantages: tolls, distance from the central cities, more convenient competing Interstates. Only permitting no speed limit or very high ones (like 100 mph) will attract a sufficient volume of customers to turn a profit. It is hard to imagine the insurance companies and the liberals agreeing to Autobahn style driving on American roads. Remember how long the wildly unpopular 55 mph speed limit stayed on the books - almost 20 years. If the Democrats recapture one or both houses of Congress next month, you may rest assured that the Feds will not consent to high speed limits.

[deport]

80 MPH is the proposed speed for the TTC.... not sure under what laws, etc.

[GeorgefromGeorgia]

In order to permit 100mph speeds like the autobahn, the highway would have to be engineered for such speeds. That will cost more. Also, maintenance on the highway will need to be exemplary. If you hit a pothole at 100 you are toast.
I doubt if those speeds will be permitted. Truck traffic might like the route to avoid congested cities.