Would Ultra-High-Speed Highways be feasible in the USA? I ask because (apparently) in Italy, there are an elite group of drivers (mostly ex-race car drivers), employed by the performance car mfgs. (MASERATI, FERRARI, LAMBORGHINI), who are licensed to drive at 160 MPH. Think about it-a UHSH would make driving long distances pretty feasible (NYC-Boston in about 80 minutes), Boston-Miami-about 11 hours!
And, many of these Italian sedans are capable-the MASERATI Quattroporte sedan has a speedometer indicating up to 180MPH. Of course, there are a few problems:
-fuel consumption at 160 MPH is likely to be pretty high
-a crash at 160 MPH is likely to be a bit more serious than at 55 MPH
-crowded roads would pose a hazard
-reaction times: you need good reflexes to react at such high speeds
Are tires capable of sustained speeds like this?
Might be fun to drive down to NYC for lunch-and return before dinner!
I’ve thought about this before; having different classes of drivers licenses based on driver competence. Assuming you mean using the existing highways and allowing drivers who have demonstrated skill and vehicle competence to drive faster than the flow of traffic, of course. If that’s the case, I don’t think it would work, for a few reasons.
First, there are too many clueless drivers who either mope along in the passing lane at well under current speed limits. Said drivers also have a habit of pulling in front of a vehicle going faster than them without regard to the relative speed differentials.
Second, how are cops going to enforce the slower drivers? Unless there was a way of identifying fastable vehicles, everybody would try to go as fast as the could without regard to reaction times and leaving enough space.
Third, I’m only comfortable going about 120 in my car on a sustained basis, so I think that should be the limit. 
Certain roads in Germany have no speed limit.
Italian driving is some of the worst driving I have seen in my life.
The hardest thing about driving at high speeds is your reaction to things ahead of you that you can’t see yet.
I’ve driven cars on interstates cruising along at 90 with little to no problems but when I’ve taken my motorcyle up to 135 a few times things change dramatically.
Traffic that is ahead of you that you can’t even see yet comes up incredibly fast and you have split seconds to react. I’ve also only done this on straightaways so I can’t even imagine how fast your reactions would have to be to handle bends in the roads or hills.
Personally, I think it’s inevitable but it won’t be from certain drivers earning a privilege but computers driving the vehicles. As the boomer ages, I expect we’ll see an increased number of incidents of cars plowing through store windows, bus stops, kids in schoolyards, while some geezer says “I hit the brakes but nothing happened!” Yeah, yeah, gramps, you stomped the gas pedal and just won’t admit it. Eventually no insurance company will be able to cover a person over 80 unless the premiums are ridiculously high or the old-timer accepts an increased amount of automated systems in his car.
The tech will spread and eventually you’ll be able to pull onto a highway and the computer will drive you, with ten feet or so between your car and the guys ahead and behind you, cruising along at 100 mph. Cars will eventually diverge a bit, with electric-only vehicles meant for tooling around town and hybrid models with internal-combustion engines tuned for optimal performance at 100+ sold to highway commuters.
I’m kinda looking forward to it, actually. Current stop-and-go highway traffic is offensively inefficient.
I think we may see limits raised to speeds more appropriate to modern vehicles, but I don’t think we’ll see anything like the Autobahn. For one thing, the faster it goes, the fewer people have any use for it, so it wouldn’t make for everyone else to pay for it. Also, we have more egalitarian notions in the US, so we wouldn’t be willing to restrict it to the best drivers. People generally expect to be able to be stupid and incompetent. Most people aren’t driving enthusiasts and don’t maintain their cars or driving skills to a very high level.
There is no speed limit outside of town on the Isle of Man.
Not much in the way of highways, either 
Clearly you haven’t ever driven on I-95.
Creating highways where one can safely drive 160mph is basically an engineering problem - simply designing the cars and the road grades for those speeds. The question is what benefit would they have? Traffic congestion is more likely to be the deciding gactor than the speed limit.
A vehicle going at 160 mph has about 8.5 times the kinetic energy of one going at 55 mph. Although kinetic energy is not a perfect measure of the damage done in an impact, it is a good rough measurement. Fuel consumption is also dramatically higher at these speeds as drag increases (roughly) as a square of speed, and unless you have a functional spoiler will probably increase lift, further reducing vehicle handling capability. Cars running at these speeds really need to be purpose designed, a category for which most cars on American roads do not qualify.
While fairly common high performance V-rated tires (up to 149 mph) are available for most passenger cars in most standard sizes, Z/ZR rated tires are limited to high performance summer/ultra high performance all season tires, usually in lower profile sidewalls. Only W, Y, and (Y) speed rated tires are certified for speeds in excess of 160 mph for sustained periods (>10 minutes). This is firmly in exoticar territory.
There is also the issue of roadway maintenance; at such speeds common highway construction will wear at accelerated rates.
Safe high speed transport (at speeds ~120-200 mph) is viable, a la bullet and maglev trains like the Japanese Shinkansen, French TGV, and German Transrapid. These are far more energy efficient, easier to maintain, and overall cost-effective (provided that there is sufficient demand to meet capacity for high speed transit) than a high speed highway network.
Stranger
When they model traffic as a fluid-dynamics system, they find that even fairly modest variations among the respective vehicle speeds are part of what create congestion. A road with significant numbers of people driving in a range that spanned say 60-120 mph seems hard to imagine.
Also as noted, human reaction times and the body’s reaction to impact aren’t getting any better. Presumably these highways would still be subject to rain, or ice, or error by other drivers, or armadillos wandering out into the road. I think I’m a good driver but I don’t have any confidence in my ability to handle any of those conditions at a triple-digit speed.
Interesting demo of traffic shockwaves. Inevitably, somebody gets a little too close to the guy ahead of him and overbrakes. The guy behind overbrakes in reaction, and soon there’s a clump of stopped cars. Cruise-control systems that have forward-looking radar or sonar or other detection systems to maintain distance will be a big help, once they trickle down from luxury cars to standard vehicles. I still maintain it’ll be the insurance companies who will be the, heh, driving force.
Ignoring the engineering challenges, there is no way it would ever happen on current highways, unless everyone (you, me, grandma, etc.) was required to drive that fast as well.
Otherwise, imagine you’re one of the few people who has the 160 mph licenses (while everyone else still has to drive 60).
At 160mph, you have just as much reaction time to avoid other cars driving 60, as you would trying to avoid a stopped car on the freeway while you’re going 100mph. Not exactly an easy task.
NO WAY IN HELL. You ever drove really fast? It’s terrifying. There’d need to be a whole separate highway system, and even if you could get enough money from the suicidal daredevil set to build this thing, you’d still have to deal with the near-catastrophic consequences the frequent accidents will have on the surroundings.
Ahhh, who am I kidding? I’d LOVE to be Speed Racer. Especially if I was assured that Trixie put out. 
You would either have to try to put these super drivers into the main traffic flow, which wouldn’t work, or you would have to build new roads specifically for them, and it doesn’t seem there would be enough demand to justify that.
If I was going to travel at that kind of speed on land, I’d rather be on rails.
How about rails running down the middle of the interstates, with platoons of linked vehicles travelling at 150 mph plus? The vehicles would need rail wheels as well as road wheels and there would have to be transfer lanes, but if we’re proposing to fit automatic controls, we can add the rail wheels at the same time. Heck, with this system, intercity buses could compete with the TGV!
Such a system was proposed back in the seventies, in the book YV88.