Crash Friendly Design

The Mansfield bars were added after the death of Jane Mansfield when the vehicle she was in rear ended a truck.

The best thing to ease the damage would be to take the phones out of the hands of inattentive drivers and have cars that stopped if the driver was not alert and attentive. The problem is the nut holding the wheel unless of course it is the Tesla's that have the steering wheels that come off.

You can't engineer out stupidity!

https://allthatsinteresting.com/jayne-mansfield-death

Should have them on the sides of the trucks as well...

Don't mess with natural selection, there is a need to reduce the gene pool of really silly people.

Might call it "natural selection;" or, more abrasive, "population control."

I think you meant this in humor. But, I would point out that highways and roadways have a lot of safety features built into them to reduce traffic accident mortality. Paved shoulders, guard rails, should rumbler strips, stop ahead signs, pavement striping, raised medians, and so forth. All these would not be considered necessary if safety and improved safe performance was not a goal.

At times, when I have been distracted, these have helped me. As I am sure they have helped you. It might add some cost, but improving the rear end of a truck or cannister vehicle to reduce mortality, seems like a wise investment.

Granted, most rear ends are probably the result of distracted driving. But what about the case where the driver could not stop (i.e. snow or icy roads), poor truck driver performance (i.e. sudden stops) , trucks that are not properly lit by running lights or have lights burned out, etc.

Again, I think you meant this to be humerous so please do not take my response as chastising you. I am just pointing out that everything should have safety as an objective and a goal.

Then they can't go over railroad tracks.

How about a large air bag with suitable sensors and processing.

https://coloradopersonalinjury.com/new-2022-underride-crash-safety-features/

One recent and prominent safety improvement feature is the placing on the rear of the truck a large projection screen, connected to a camera on the front of the vehicle. Divers of following vehicles get a truck's-eye view of the road in front of it.

In order for trucks to fulfill their function, plus being too high, there isn't much choice except something in the space where the ICC bar is. There might be several feet of space there--but probably not on dump or tow trucks where the last axle/wheels have to be toward the back. For dump trucks that haul asphalt for paving, don't the paving machines actually push the truck as it is unloading into the paver?

Umpteen many years ago, when my company was working on break-away street lighting poles, they used a product called "hexcell" to absorb and measure the crash energy. But that was expensive stuff! But perhaps that idea could be utilized to make an energy-absorbing space at the back of most trucks.

As Stef said, the best method might be to remove distracted drivers. In the fire protection field, some fire departments are using out-of-service apparatus parked behind the scene to protect the firemen/paramedics from the drivers who "try" to run into them.

The last photo looks like a Ford Model T hauling a trailer filled with cases of (beer?)