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.
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.
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.