For a lot of reasons, I don't drive as fast as I used to. One of the big ones, I can't afford it.  I can't afford the speeding tickets, and I if you drive the speed limit (and keep your tired properly inflated) you get better gas mileage. In Maine, north of the Old Town area you can drive 75. In Texas, you can go 85.

On 40 miles of a toll highway between Austin and San Antonio, Texas you can now legally drive that fast.  The thing cost about a billion and half dollars to build. It is a public/private project     and the builder will be sharing the toll revenues with the state of Texas. Is it safe? Well the builders say yes, as long as people keep their hands on the wheel and eyes on the road. Duh, good advice on any day!