[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.