45 vs. 25 mph in residential zone: child runs out in front of you, hit the brakes but you can't stop in time, hit him still going 30mph and kill him... vs. you stop and don't hit him.
100 vs. 65 mph on freeway: you certainly die vs. you probably die, depending on the accident. Freeway accidents are very bad at either speed. Luckily, there shouldn't be any pedestrians, children running into the street, or bicyclists.
The danger of freeway speed has more to do with differentials. Accident risk goes up 2x every 15-20mph of raw speed but 2x every 3 mph of speed differential (in either direction). If you're in traffic and driving 100 mph, you're probably an asshole because most people won't be, but it's the speed variance (and weaving, tailgating, and other asshole behaviors) that makes it dangerous.
100 vs. 65 mph on freeway: you certainly die vs. you probably die, depending on the accident. Freeway accidents are very bad at either speed. Luckily, there shouldn't be any pedestrians, children running into the street, or bicyclists.
The danger of freeway speed has more to do with differentials. Accident risk goes up 2x every 15-20mph of raw speed but 2x every 3 mph of speed differential (in either direction). If you're in traffic and driving 100 mph, you're probably an asshole because most people won't be, but it's the speed variance (and weaving, tailgating, and other asshole behaviors) that makes it dangerous.