lower speeds are my guess. In Texas you need a lifted dually just to commute 8 miles or get groceries and the speed limit is 70-85 MPH not 80kmh.
(Mass x Velociy x velocity)./2
A Fiat sized car doing 80 km per hour (50 mph) has a lot less crash energy than an 8,000 pound dually doing 75 MPH (120 kmh)
223,996 joules vs 2,039,581. The dually has 2 million more units of energy at the moment of impact than the fiat doing 2/3rds of the speed of the dually.