speed is a poor proxy metric for injury/death, but it’s mediopolitically expedient and as such used regularly to misdirect conversation and policy. to reduce injury/death, we need to address distracted driving, reckless driving, and impaired driving. notice that all of these share ‘inattention’ in common. also note that it’s very hard to legislate attention, which is why the conversation gets misdirected toward speed.

however, there are measures like narrowing car lanes, adding street trees, and installing bike lanes that have positive effect on attention by making collision dangers more obvious (without making them more likely). these measures tend to also lower speed, but lowering speed shouldn’t be the primary goal, lest we implement more ineffective measures like speed limits and speed humps rather than the effective ones.