On the contrary, speed limit reduction from 130 to 100 km/h (82 to 60 mph) reduces road safety since a lot more people drive faster than the rest of the traffic, and do so aggressively around those blocking the lanes at the speed limit. Emissions are increased when one constantly accelerates above speed limit then breaks for possible camera / police traps.
Germany is the last free country on this over-regulated planet. Well, German autobahns are, the country is one of the most bureaucratic ones.

Good points on capacity of planes!