We, not as bay staters or Americans, but I truly believe as human beings, are programmed to have a very difficult time understanding that our experience of something can be entirely different than that of others. Plug that problem into a democratic system and you have...well...everything going on both locally and nationally. It's a crisis of empathy. Your housing crisis isn't my problem, I have my property values and neighborhood character to worry about. Your traffic deaths aren't my problem, it's an issue of individual drivers/bikers/pedestrians.
I'd like to push back on that just a little bit. While I won't speculate on how much empathy plays a role in these viewpoints on traffic violence, I will speculate on the role psychology might (and probably does) play. With low probability events (like a serious crash at the aforementioned intersection), people typically either perceive a significantly higher probability than reality (hypothetically going from 0.001% to 1%), or view the probability as effectively zero. With an intersection like this, there will be tons of drivers that have used it for years without ever getting into an wreck, a may only remember minor fender-benders that occurred there. Collision risk is unlikely to be something that is considered at all, unless prompted, when most drivers think about this intersection.
One thing that could help communicate these dangers better (and you may already do for all I know), is to compare the crash frequency in one location to some other health and safety data in the surrounding area. Using a reference to something that is often viewed as a more serious problem really can be influential. For example, in Wellesley (just to pick a random, wealthier suburb) one small stretch of roadway from 2017-2022 had more
injuries (17) than the town had murders (0), rapes (16), or robberies (5) in the same time period (if this somewhat
dubious source is to be believed). I would imagine many towns have similar numbers, and that these comparisons could be reasonably made to a number of other crime/injury/mortality statistics.
All of this is not to dispute that many people are and will remain callous to traffic violence, even in the face of new evidence. I just personally believe (and have experienced with a self-selected group of friends) that most people have a pretty hard time wrapping their head around this and won't be so stubborn once they can fully understand the danger.