I guess you meant to say America's restrictions on driving skill to obtain a license are too lax.
That's only a part of it.
A lot goes into those numbers.
Indeed. That's why I didn't base my entire post on them.
Perhaps you meant to say "Americans aren't knowledgable enough of their vehicle's capabilities" instead of "incapable of handling a vehicle properly".
Those two sentences mean the same thing in the context of my statement.
Perhaps you meant to say "Americans do not pay sufficent attention at the current speed limits, and would likely continue to pay insufficient attention at higher limits."
Only a part of it.
There's nothing inherently inferior about Americans...
No comment.
...and there's no reason to think that there is no way to implement an unlimited speed limit highway in America from a driver's skill point of view.
You know those highschool experiences that you look back on and go, "wow, what a dumb idea that was"...? One of my own experiences was going out driving with a few friends and showing this girl (who was driving her dad's Buick) a long, straight rural road north of town where you can hit high speeds easily. With absolutely no factors besides her, the car, and a perfectly straight road, she managed to lose control and swerve off into the ditch.
Other than perhaps the willingness to try something like that, the only difference between her and any other average american driver is experience. She was taught the same things that any other american driver is taught -- 1. the rules of the road, 2. what the signs mean, 3. where the steering wheel, gas pedal, and brake pedal are, 4. to fear hydroplaning above everything else in the entire world, and 5. to steer into a slide (the girl certainly remembered #5 -- she overcorrected twice before sliding off the pavement backwards).
However, although it could certainly be improved, our driver's education system doesn't really deserve the brunt of the blame. What makes things worse is that americans have little to no incentive to learn anything more, and establish poor habits. For example, the prevalance of autotragic transmissions in this country causes drivers to pay far less attention than they would if they had three pedals and stirred their own gears, and encourages other non-driving-related activities, such as text messaging, eating, or applying makeup. Meanwhile, as wfooshee pointed out, cornering is thought of as an annoyance and is avoided when possible (even in the construction of our roads), which means that the average driver doesnt even know how to take a corner at 3/10ths, much less maintain control in any emergency situation.
With proper education and, more importantly, a shift in the way this nation thinks about cars and driving, sure, americans could handle a high-speed highway. Driving fast in a straight line (or a counter-clockwise oval) is what this country loves, anyway.

But as things are now, between the ricers who think they're the gR34t3sT dR1v3Rs 3v4R and the average Joes/Janes who wouldn't even begin to know what being a
good driver entails, I'm not even slightly convinced.
Ironically, I'm expecting dozens of American GTP members to chime in agreeing with you - even though each one of them proves your statement incorrect just by agreeing.
By being a member here, they've implied that they're a car enthusiast to some extent, and appreciate racing videogames that, at the very least, are more true-to-life than something like Need for Speed. I don't know about wfooshee, but that excludes them from my "average american driver" generalization.
Whether or not they're any good at driving remains a question, but they're still different from the people who think of a car as an appliance.