My experiences are the same as yours, but you've clearly spent more time there than me. I would say the two greatest differences between German Authobahns and

My experiences are the same as yours, but you've clearly spent more time there than me. I would say the two greatest differences between German Authobahns and US interstate traffic comes down to two factors: - road condition and maintenance. The Autobahn roads are near perfect in design, drainage, signage and smoothness - driver attitude : as you noted, 'undertaking' or passing on the right is not only illegal, it is considered to be rude. Someone driving faster than you is in a hurry, not throwing down a challenge to you. You let them on their way, not try and impede their progress. A single flash of the lights to a slower vehicle to move right is not considered rude. - I would disagree on the average 80-90 mph on the unrestricted sections. I would estimate that most occupants of the 'fast' lane in ordinary vehicles would be doing 100-120 mph. Another bonus of the Autobahn system is that 'normal' cars are more popular than SUV's because you just can't drive SUV's that fast, unless you have a high-end Mercedes, Porsche or BMW. Having an artificially lower speed limit encourages oversized vehicles because the speeds are low enough that their mass and frontal area don't affect progress and fuel consumption as much. While I would say the study probably has some merit, it's very important with these time based studies to allow for the increased driver survival rate in more modern cars. I did not see that with this study, but it can be a crucial factor.