Why would it impact braking distance? Aside from "everything affects everything" of course. I can't see this majorly affecting the overall vehicle's momentum or braking ability at any given speed, and speed limits wouldn't change.

It would impact braking distance because if the air isn't slowing the truck down as much then it will take longer for the brakes to slow the truck down.

That doesn’t matter much for slowing a truck down due to the high inertia. Really good low rolling resistance tires (Super Singles) should actually reduce stopping distance as they generally have a bit more contact area. You want low amounts of slippage on the tires while driving as slippage is wasted energy, which should give you more margin when you need to slow down.

Electric trucks also have a massive advantage in mountainous terrain due to ability to dump energy into the battery instead of the brakes which can and do overheat.

Oh that's a great point. It reduces drag, which would normally help braking distance. Thanks for explaining, I was genuinely having trouble thinking of how it could affect things.

Deployable parachute behind the truck and for super emergencies the front backwards facing rocket engages, duhh

Who cares about braking, the cone acts as an airbag!

Okay buddy, how about you let your car/truck/SUV be hit by a 150,000 lbs “airbag” and I will watch from afar to see what happens. I’m thinking pinball and the lanes as bumpers, yeah?