In my opinion, this is an incredibly stupid move. After reading a couple article about the Texas speed limit increase, I noticed that the primary concern is about reduced fuel economy with little or no mention of safety.
Most everyone generally knows that higher speeds increase stopping distance, crash severity and affect how a car handles. Few, however, seem to be aware of how high speeds affect tires and that tire failures at high speeds can have catastrophic results.
If you're driving a new car, in perfect condition, properly loaded, with new, properly inflated tires, you're in good shape. But it all goes downhill from there.
1. Passenger car tires are load, speed and temperature rated for a particular application. If you have replaced your tires with those of the wrong size or rating, you could have a problem.
2. If you have had a tire punctured and patched, it no longer meets its stated load/speed rating.
3. If your tires are over 5 years old, they are no longer covered by most tire manufacturer's warranties, regardless of mileage. (Tires simply degrade with age.)
4. If even one tire is underinflated by only a few PSI, it will generate a lot more heat at high speed and will be prone to failure.
5. A heavily loaded vehicle, rough pavement, high ambient temperatures, bad alignment, bad shock absorbers or any combination of these will result in higher internal tire temperatures and bring them closer to failure.
6. Combine a high speed tire failure with the fact that most people don't know what to do when a tire blows and an accident is very likely.
7. Tire failures can also result from hidden manufacturing defects but you usually don't find out about them until it's too late.
Visualize this: You're cruising down a Texas freeway at the posted 85 MPH limit, in your new Lexus. A 17 year old kid pulls up next to you in his beater '73 Camaro. His car is riding on one new tire, one bald tire, one retread and a temporary spare. You can't see that he's missing one lug nut on one wheel and two on another. His front end is out of alignment, the ball joints need replacement and all his shocks are worn out. You wanna be speeding down the road next to this "accident waiting to happen"? Chances are good that when one of his tires decides to self-destruct, he will take someone with him.
No, 85 MPH is too fast for public roads when 20%* of the cars on those roads have substandard tire conditions of one type or another.
*Based on my own observations.
http://www.car-accidents.com/pages/9_firestone/stories/1_ford_Explorer.html