I seem to recall the original LA-style HAWK (three-head signal) had no solid red phase. Solid green > Solid Yellow > Flashing Red > Solid green.
In theory, drivers have a flashing red, and must stop anytime the signal is active. So the danger to pedestrians should be very minimal unless they just straight up run the flashing red.
This is correct. No solid red, just flashing red.
I believe that the safest ped crossing singal would be teh LA signal modified with a brief solid red phase at the beginning of the crossing. THe solid red will force people to stop to see what is happening, and then after a few seconds, cars can proceed assuming that there are no pedestrians still crossing.
Besides Cambridge, Massachusetts and the other cities listed in the story, New York City (in all five boroughs) has always prohibited right-on-red except where permitted by posted signs.
Correct. But most Boston area signals have turns on red prohibited with signage. If you go to any traffic signal randomly on google maps in Massachusetts, there is a roughly 70% chance you'll find at least one no turn on red sign, if not more.
MA is generally a very dense state. So in much of the area, there are significant numbers of people crossing.
NTOR is justified in any significant pedestrian heavy area. While I am not a fan of blanket RTOR prohibitions, I think it is fair to assume that putting in NTOR signs in downtown areas and within walking distance to major transit stations is generally justified for safety reasons.