the-missile:
Time response is impacted by speed, vision angle is narrowed by speed so any miss or any error at higher speed will automatically lead to a more dangerous situation...more info to treat so obviously more risk as more focus is involved hence more fatigue!
In term of energy and as Gnil mentioned, a crash at 200 is not the same as the one at 100 because of energy accumulation.
Add to that, more consumption, quicker wear of the entire system, etc...
Faster speed on roads are safer than slower speed is obviously a non sense but it also depends on the situation and location. Try 200km/h on autobahn on a limited 110km/h is not safer. the opposite situation will not be better though but there is a minimum speed on highways for a reason...
Try 80km/h in a city center with loads of pedestrians instead of 30km/h or 50km/h will not be safer as well.
Compare apple to apple within the same basket...otherwise it is completely biased.
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GT Lover, Porsche fan
991.2 GT3 manual
Cayenne GTS 2014
No one here is saying speed ISN'T a factor. It is still, but not a major one like paying attention while driving.
When one is talking about speed, it's not the absolute speed that's important, it's the relative difference in speed between objects.
Mike's post about 85th percentile is about minimizing the relative speed between objects on the highway. Most people die at a speed they are comfortable at, regardless of what the posted limit is, and that's the flow of the traffic speed, a natural equilibrium or sort for that stretch of road. It could be AT the speed limit, or it could be at 10 over, 20 over or 10 UNDER. Any deviation from that flow of traffic speed will be dangerous, be it faster or slower. The slower than flow of traffic cars post more danger to the others than faster cars simply because they will be a moving barriers for others, especially if they don't check mirror before pulling out to the passing lane.
Germans are better drivers in general simply because they are much better educated on driving. Keeping right unless passing is ingrained to them. THAT one point is the single most important point for safe driving. Next up would be checking mirrors and surrounding and be aware and alert at all times for events. Of all the places I have driven in the world, I feel the safest on German roads. Cars on highway with German plates seldom, if at all, try to force their own passing maneuver. They could be coming up to a slow moving truck and needed to either pull out to pass or slow down and wait. German plated cars most often than not will slow down if they see someone coming up fast on the passing lane, they will wait their turn after the fast car have passed. The worse ever I have seen are the ones with the ugly yellow NL plates and a lot of the North American drivers, they do not check their mirrors before pulling out, ignoring what's coming up behind them, and worse of all, most of them actually slows down after pulling out and do their pass. 
These people have zero spacial awareness and shouldn't even qualify to get a driver's license in the first place. They have absolutely no idea that what they are doing is endangering themselves, their passengers, the cars coming up behind them and also the car/truck they are passing.
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Or at 100 kph for that matter?
, I think they all went to same driving schools
