If the cargo is fully contained in a sided vehicle, what is the minimum requirement for withstanding sideways force?

A 0.5g (50% of cargo weight)

explanation

Note: If the cargo is contained in a sided vehicle, the vehicle structure MUST be strong enough to withstand the forces described earlier.
Forward force: 0.8 g (80%)
Rearward force: 0.5.g (50%)
Sideways force: 0.5 g (50%).