The city Department of Transportation enacted a new “Regional Slow Zone” for everything south of Canal — including Canal — as of last October as part of Sammy’s Law — and I am just catching up to the news. Can’t say I have seen a new mph sign around? But I did confirm with the DOT, since Lower Manhattan is not on their list online. Our zone is now 20 mph.

Google Maps still shows the speed limit as 25, but I finally spotted a 20 mph sign in front of Washington Market Park.

The speed limit is 15 next to schools, including a dozen in Lower Manhattan.

Lower speeds reduce crashes and also decrease the chance of fatalities when a crash does occur. This is an old story from Wired, but it explains the physics — and impact on the human body — pretty well.