I don't think your interpretation about speed limits is correct compared to other factors mentioned in the nytimes article:
> more stringent enforcement of moving violations, revamping hundreds of street corners to slow down turning cars and rejiggering crossing signals to give pedestrians a head start.
For one, traffic in NYC just doesn't move that fast, especially on the streets where most of the accidents happened. It's not really appropriate to extrapolate NYC data to the rest of the United States unless you focus only on urban centers.
Second, almost all of the fatalities seem to happen around intersections. I'd expect to see more jay walking deaths in the years before the speed limit change if your interpretation was correct.
This is probably the biggest one. Lots of pedestrians and get hit by people turning right who can't see them until the last second because of other things on the street corner (like people waiting to cross in the other direction).
There are a few intersections in my city that are notorious for this; I have an extremely loud airhorn on my bike that I use to blast drivers who allow their vehicle to move forward without looking where it's going.
I no longer believe RTOR can be performed safely by the majority of drivers— it should be banned.
Having recently been teaching someone to drive, I have strongly encouraged them to not engage in right turns unless it is clearly safe and there is no on coming traffic. Better to wait a minute than to risk hitting someone. The problem is there parents feel differently, as do the drivers waiting behind us. If people were more patient drivers, less pedestrians (and drivers) would die.
My point though is that people do just fine without it.
I would like to be able wait for the light to change without feeling like I'm being an asshole to other drivers behind me.
All major pedestrian intersections should be "all walks," where a period of time is established where no cars may enter the intersection.
If you're turning right onto a road from a private residence, then you're probably only looking in the direction traffic is coming from. Someone biking the wrong way could easily be hit.
1: https://www.npr.org/sections/health-shots/2014/05/15/3124556...
To slow down local neighborhood traffic my neighbors put out an old single construction cone (someone has a source of heavily used cones so when they're stolen no big deal) in the middle of the road.
Folks slow down and easily drive around it. It is highly effective even when it isn't there as I suspect the local speeder folks anticipate the random construction cone might be back at anytime...
2014 (2 months of 25mph) : 140 pedestrian fatalities
2015 139 pedestrian fatalities
2016: 148 pedestrian fatalities
For a limited-access road or grade-separated road (especially electronic toll roads), simply minimizing the speed difference between cars is enough.
For the pedestrian case, you want to minimize the speed difference between cars and pedestrians. Speed limits are only part of a plan to accomplish this goal -- instead, you want affordances that make people naturally drive slower: removing car lanes (replacing them with trees or sidewalk or protected bike lanes), narrower lanes, adding curves to the road (but without adding blind corners), adding pedestrian crossings, and so forth.
"The common US rule requiring speed limits to be set at 85% of actual average car speeds amounts to crowdsourcing the value of human life, on a platform where only motorists have a voice."
(https://twitter.com/humantransit/status/1123264831790899200)
But in busier roadways, what I've observed is that slow drivers tend to be biggest danger now - and that is naturally because slow drivers tend to also be distracted drivers (by cellphones or otherwise). Naturally, such distraction is a bigger and bigger phenomena and dealing with them by making it clearer how they ought to drive seem OK.
Driving too fast results in more fatalities.
It might be nice to decrease both, but I know what I care more about reducing.
Devil's advocate, but crash fatality rates have been on a downward trend for decades.
Some safety features like automatic emergency braking, abs, stability control, and modern (more powerful) headlights protect pedestrians as well as drivers
Somewhat recently, many cars have been specifically designed to reduce injury when colliding with pedestrians, and these models have become more common in the 2014-2018 window.
I wouldn't completely discount the research, but the majority of the reduction could be that newer cars are simply safer for everyone
Also, your claim that it’s lower speed limits that reduced deaths seems not entirely honest - the articles say that there were more things that changed besides speed limits.
This is likely false.
NYC changed the speed limit to 25 mph in Nov 2014. Pedestrian deaths have been sharply reduced:
1) https://ny.curbed.com/2018/1/8/16863408/nyc-vision-zero-traf...
2) https://www.nytimes.com/2018/01/08/nyregion/nyc-pedestrian-d...
At the same time pedestrian deaths in the US as a whole have increased:
https://usa.streetsblog.org/2019/03/01/pedestrian-deaths-rea...
The data is clear that lower speeds means accidents are less dangerous: https://usa.streetsblog.org/2016/05/31/3-graphs-that-explain...