Vehicle size makes them more dangerous

[Old Crank]

5. PArt of the answer

is to make it so you can't speed. Cars can only go the speed limit monitored by your location. The cars I rent in Europe all know the speed limits, even in construction zones.

Another big issue is the front ends of these beasts. They are deadly when they hit people. Lower the hoodlines and slope them more intstead of a wall. Then work on visibility. More mirrors so you can see in front and down the sides.

Cars get better fuel economy. Quick look. Chevy Malibu 2023, 30 mpg. Chevy Tahoe, 16-17 mpg depending on gas engine. Diesel gets 22. But diesel costs a bunch more and are even more polluting.
The Silverado gets 24 if diesel. The gas engines get 20 for the 4 cyl. and as low as 13.

Bigger heavier vehicles burn more fuel.