Lets say you are driving at EXACTLY 50 mph and I am either ahead of you or behind you, but I am also going EXACTLY 50 mph. Can you please explain how you could hit me (or I could hit you)
If we were separated by 200 feet, we'd ALWAYS be separated by 200 feet.
Now if I'm behind and you are going exactly 50 and I'm going EXACTLY 65 - we are gonna have an issue of non-constant spacing- IE a potential accident.
If EVERYONE is going exactly 50 - no issues.
If Everyone is going EXACTLY 75 - no issues - no collisions are possible at all!
But if one person is going either 50 when traffic is doing 75 OR one person is doing 75 when traffic is doing 50 - issues arise, collisions occur, and deaths are possible.
The scariest ride I ever had was with my mother, when she was well into her 70's.
She had been taught that the safest and most economical speed was 50.
So there she was driving down the highway at 50. Problem was - Canada had become metric and her Nissan had a speedometer that read in Km/hr. She was doing 50 kph (approx 30 mph) in a 110 kph (70 mph) zone.
There was NO way to convince her that 110 was a safe speed, because "she KNEW that 50 was "safe" and nothing faster was safe!
So for those who think it is not important to move with traffic- try driving 30 on a multi-lane where the posted speed is 70. Leave instructions for your heirs and executors to let us know how it worked out for you.
I don't think ANYONE is saying you always have to drive at the posted limit, (after all, the signs on the highways still read the same even in a blinding snowstorm!) but you should make EVERY attempt to move WITH traffic and not create an accident by being out of step. (and if your trailer tires
can't keep up - well that's a separate topic that just reinforces my own view that, in rating a tire as ST, the manufacturer is stating that they realize it is not safe to use for any purpose whatever)!