Tragic truck accidents

Two multiple fatal accidents within two days, and all the reporting and comment emphasizes that they were caused by big trucks. As a former big truck driver who has come close to this same situation (come to think of it, I was actually involved in one that fortunately was no where near that devastating but that’s another story), and who has also had a friend killed by an identical one, I’d like to shift some of the blame.
Both the recent wrecks, and the one closer to me, took place when traffic was stopped for previous incidents. If you’ve ever been surprised by a vehicle stopped in front of you when driving your car (or fire truck, ambulance, pick-up, SUV, whatever) you know the drill: “Ohmigawd, that car’s stopped! I gotta take my foot off the gas and put it on the brake - I gotta pull to the left/right to avoid it. I gotta hope my car stops in time!” Most of the time you can avoid a crash. You’re probably usually driving a vehicle that weighs a couple of tons, and even at 60 or more mph, you can stop it fairly soon.
A big truck, fully loaded, can legally weigh up to 80,000 pounds - 40 tons. And even with ‘those great big brakes’ that weight and inertia take at least the length of a football field to stop. Probably more, given the speed limit on the roads where these happened (I-65 in Indiana, Will Rogers Tpk in Oklahoma)is I think 70 mph. Simple physics, folks.
Law enforcement should know this, maybe some of them do. So why, whyinhell, don’t they put a warning car or lights, signs, whatever, at a point before the stopped traffic and yes, keep moving it as the stationary vehicles build up, to warn oncoming traffic? Safety of those working at the scene is a top priority, why isn’t safety of those held hostage by the scene?
How many of us have been on a scene and observed multiple law enforcement personnel standing around playing pocket pool, doing nothing to protect anybody? Surely there’s a better deployment of that resource to perhaps save a life - or five, or nine?
When discussing the incident where my friend was killed (where there was no wreck, traffic was stopped by the troopers because there was a person threatening to jump off a high bridge) with a trooper, I asked why they couldn’t have kept one of the three lanes on the bridge open to let traffic through, she (yes I said she) replied (in the ‘I’m the trooper therefore I know’ tone that we’ve all experienced hearing) ‘Do you know how many accidents that could cause!” Another person in the conversation answered ‘Seems to me what you did, did cause one.’ Hmm-she had no answer to that.
So I want to shift some of the blame to all those people who don’t do anything to protect the innocent bystanders - the stopped traffic. Let people know there’s traffic stopped ahead - can’t be that hard to figure out how. Is it an idea that might save lives? I think so. Is it ever gonna happen? I doubt it. Sigh.
Sympathy to all those involved in those horrific wrecks: the victims and their close ones, the truck drivers who now have to live with what happened under their wheels, and the responders who have to deal with it, hope they have good support teams.