by Thomas I
MDNFan wrote:The normal design-speed of Autobahns is 120km/h. (A few one have 140km/h design-speed, Autobahns with less importance only 80 - 100km/h)
It is worth noting that the Interstate system at present cannot be "safe" over about 80mph or so.
The Autobahn was designed from the onset as a high-speed throughfare. This includes limitations on grade, radius of curvature, minimum sightlines, maintenance, and subgrade.
Grades are up to 8%! Kurves are down to a radius of 500m.
In such places there are speed limits of 80, 100, 120 or 130km/h...
An there are stretches where 200km/h means coming to the limits of of physics (yeah Kassel-Mountains....)
But there are only one exit to the left in the whole network!
MDNFan wrote:The Interstate was designed as a low-speed military transport net. It was never designed for the speeds you see on the Autobahn. The subgrade is HALF the autobahn's thickness, its not as durable, grade & curvature limitations are much more liberal, and sightline limits are much less. That's not factoring in the maintenance differences & the deadly "straight shot" highways like I-80 and I-57 <snooze>.Btw. subgrade:
Truck can have an axle load of 11,5 metric tons (double axle load (4 wheels = 1 axle: 19 metric tons, triple axle load = 24 metric tons) on Autobahns . Thats more than allowed on intersates i believe...
MDNFan wrote: In addition, traffic flow is much more varied, cars are not maintained nearly as well, and drivers just don't seem to understand the performance limitations of their cars (a typical American commuter car at 90mph is a projectile- NO swerve capability whatsoever).Car maintenance and drivers ability can be a problem... sure.
MDNFan wrote:What does this mean for traffic in the future? We can either:Burn a lot more fuel must not become true.
1) drive slower, take longer, and maintain the current system.
2) revamp almost the entire "I" system to allow higher speeds, upgrade maintence & driver requirements to allow safe travel at Autobahn speeds, and burn a lot more fuel than we do now (A= (motive force - bv)/m)
3) build HSR and relegate cars to intracity & rural use.
Which do you think is more likely?
The average consumption in Germany is 7,5 litre per car and 100km - in the USA it is about 12,5 litre. If you allowed to drive faster you will favor other cars...
Btw: If americans would use diesel engines for her cars in the same extent as french ore german people the USA would save oil as much as they import from Saudi-Arabia...
Saudis wouldnt like this - but maybe that means fewer moneys for terrorism.