Research from the 60s has a relative speed/crash incidence curve. It’s lowest for cars going a little above the median speed, about equally dangerous going either way from that in a U shape.
Some subsequent research affirms this curve, others call it into question. My own, informal read is that the stronger research generally affirms it.
Speed-CAUSED crashes don’t factor strongly into fatal crash counts. Also, a general trend of increasing rural road or freeway (urban and rural) speed limit increases in the US since 1995 has accompanied continued plunges into record low highway fatality rates.
Also, all crashes are relevant. Fatalities can’t happen when there aren’t crashes.
It doesn't matter if the primary cause of a traffic accident is speed. The relevant question is:
"Would this person have died if the cars were driving slower?"
And simple physics tells us that almost always the answer is "No".
If you try to argue that driving faster is safer, you need to provide strong evidence. Statistical correlation over a time frame where cars and roads have been made much safer doesn't really convince me. Even a correlation between driver speed and collision risk is meaningless -- eg. people with poor vision generally drive slower, but are still more dangerous than drivers with good vision.
(I'm not saying that driving fast is unsafe in general. On a well maintained road with good visibility you can drive pretty fast with minimal risk. All I'm saying is that, all other things being equal, driving slower is almost always going to be safer)
I don’t disagree with the idea that if you’re going to get into a crash, that a slower-speed crash is usually less risky. Where I disagree is that we can stop at basic physics and ignore so many other factors. A focus on physics is kind of like the “but if it saves one life” argument, which is fallacious because it’s contemptuous of all other views.
It is not simply the case that anti-speed crusades result in safer roads. The USA’s 55 mph experiment a was a failure in that regard, and Vision Zero campaigns aren’t delivering on promises.
We really need to focus on crash elimination, which is not a hyper focus on speed. Crashes that don’t happen can’t injure or kill.
My main point was that we shouldn't tell people to drive faster. Every time an argument like this comes up, people on the internet start arguing that slow drivers are causing accidents. Open a random Reddit thread and it's full of people bashing slow drivers.
But I really doubt that slow drivers are inherently dangerous. Especially since a lot of road users are slow and can't drive fast (big trucks, tractors, mopeds, bicycles, RVs, cars with trailers, etc). So the focus must be on making sure that drivers are attentive and have good visibility, not telling slow drivers to step on the gas.
Slow drivers do increase crash risk if their slowness is done irresponsibly, which many of us see all too often. We all need to be courteous to each other, and driving slowly does not absolve one of that.
Sometimes, the right thing is for slow drivers to speed up and go with the flow.
Correct, and we’re missing these bad drivers since the basis of nearly every last traffic stop (yes, I’ve studied the data from several angles) is “speeding”. The further you lower limits, the more who are “speeding”.
Some subsequent research affirms this curve, others call it into question. My own, informal read is that the stronger research generally affirms it.