[rustybelt]

Are you arguing that drivers don't have any control over their level of risk on the road? Sure they can't eliminate 100% of risk, but not speeding and not driving drunk absolutely influences a driver's likelihood of being in an accident.

[clairity]

no, speeding hardly changes risk at all, but reckless driving certainly can, but that’s beside the point. the point is that changing your own behavior (i.e., “control”) has a negligible marginal effect on reducing your overall risk. nearly all of the practical risk is external and therefore out of your control (unless you manufacture additional risk by being distracted, reckless, and/or impaired).

you can’t really lower risk, which is what “control” implies. that’s simply a falsehood some folks choose to believe that’s unsupported by a basic application of stats & probability.

[zip1234]

Speeding doesn't change risk? When 'speed was not a factor' in a crash, it just means that the involved drivers were not driving above the post speed limit. It doesn't mean that the drivers were driving a safe speed. In fact, clearly they were not.

[clairity]

speed increases the severity of collisions, but generally doesn’t cause them (most of what we classify as speed-related is really recklessness, which is also typically a misassessment of risk). distractedness, recklessness, and impairment are the overwhelming causes of collisions, with a small additional portion caused by vehicular homicide/suicide, mechanical failure, and environmental factors.

[zip1234]

Regardless of semantics, there are known road design and electronic/mechanical techniques that can prevent or discourage speeding, regardless of the reason for speeding. The faster a vehicle is going, the more momentum it has, which correlates with risk of death in the event of crash.

[clairity]

the point is that there's no reason to target speeding specifically. you want to target distractedness, recklessness, and impairment to reduce accidents, thereby obviating the problem with speed exacerbating injury and death.

i'm all for narrowing lanes and adding trees to streets as traffic calming measures in urban neighborhoods, but that's because it increases attentiveness, rather than reduces speed per se. speed governors, on the other hand, are bad because they could prevent a driver from speeding up to evade a collision.

[rustybelt]

A quick google is telling me that 26.8% of drivers who were killed or severely injured had alcohol in their bloodstream. Assuming that's true, then wouldn't never drinking and driving reduce your risk of death or serious injury by around 26.8%? That seems like a substantial reduction that is completely in the control of the driver.

[clairity]

no, you have to get everyone else to stop drinking and driving, not just yourself, to get that sort of reduction.

[TylerE]

No you don’t. Over 50% of crashes are single car accidents. I suspect, but don’t have proof for, that that percentage is even higher in alcohol-related crashes (eg driver nods off and drives into a ditch/telephone pole

[rustybelt]

How? The 26.8% is just drivers with alcohol in their system. If I never drink and drive, I will never be part of that group. That means the raw rate of traffic fatality or severe injury is 26.8% lower for people like me (non drunk drivers.)