This is the Autobahn near Werfen, Austria.  It is two lanes in each direction with a metal rail separating opposing lanes.  Curves are not typically banked, and you can see that there's not much "shoulder".  Contrast this with the typical Interstate highway in the U.S.: two lanes in rural sections, at least three in urban sections; wide medians; wide shoulders and cleared setbacks; banked curves; long sight lines.  On a highway just like the one above between Munich and Frankfurt I cruised at 180kph (about 115mph) while VW Beetles passed me like I was parked.

Makes you wonder, doesn't it?  How is it that Austrians and Germans can do 230kph (safely!) on roads we would consider "secondary" while their American cousins are restricted to 120kph (and kill themselves right-and-left) on roads the likes of which Europeans can only dream about?

The answer, of course, is "lane courtesy".  On the Autobahn, moving to the right is mandatory whenever faster traffic comes up behind you.  It doesn't matter how fast you're going — if someone is catching up, you're "slower traffic".  American highways are unsafe not because drivers speed, but because too many drivers fail to yield the left lane for passing. 

Given that the U.S. is very much larger than Europe (we have farther to go) and our Interstates are deliberately designed for high speeds (the worst sections can handle 85mph — 135kph) isn't it about time we put all that engineering know-how... not to mention the billions of taxpayer dollars they cost... to good use?  In 1997 after Congress dropped the Federally-mandated 55mph limit for highways, the State of Montana instituted "reasonable and prudent" as their daytime speed limit; in its first 9 months, accidents and fatalities in Montana dropped 28%.  The cause of the sudden increase in safety appears tightly coupled to lane courtesy — drivers could no longer monopolize the left lane because they're "doing the speed limit".

Given the accumulating evidence that artificially low speed limits may be responsible for many of our highway fatalities, we ought to be seriously considering having no speed limit on our Interstates.  The Interstate System should be "America's Autobahn".

Yes, I know that would rob many rural communities of the revenue they get from issuing speeding tickets, but U.S. highways should not be simply a 'cash cow' for local government.