Helsinki records zero traffic deaths for full year

"More than half of Helsinki’s streets now have speed limits of 30 km/h."

This is the only secret.

People over speeding is what kills.

They lowered the speed limit by 5mph (8 km/h) throughout the entire town I live near. As far as I can tell, it just means that people now drive 15mph over the speed limit when they previously were driving 10mph over.

The last fatality on the major road closest to my house involved someone driving over 60mph in a 45 zone.

There was also a near-miss of a pedestrian on the sidewalk when a driver going over 100mph lost control of their vehicle. That driver still has a license.

I don't think lowering the speed limit to 40 (as they recently did) would have prevented that.

Yes, that's why the second half of the equation is structural traffic calming: you both need to lower the speed limit and induce lower driving speeds. The US has historically not done a great job at the latter, and has mostly treated it as an enforcement problem (speeding cameras and tickets) rather than an environmental one (making the driver feel uncomfortable going over the speed limit, e.g. by making roads narrower, adding curves, etc.). You need both, but environmental calming is much more effective on the >95% of the populace that speeds because it "feels right," and not because they're sociopathically detached.

That's slowly changing, like in NYC with daylighting initiatives. But it takes a long time.

(European cities typically don't have this same shape of problem, since the physical layout of the city itself doesn't encourage speeding. So they get the environmental incentive structure already, and all they need to do is lower the speed limit to match.)

> the >95% of the populace that speeds because it "feels right," and not because they're sociopathically detached.

What about driving over the speed limit makes one "sociopathically detached"?