Allow drivers to pack double stacked cargo

Allow drivers to pack double stacked cargo as long as (1) the cargo on the top is fully supported by the cargo on the bottom and (2) the cargo on the bottom has a flat top and isn’t double tall such as cargo containers and oversized cargo containers. 

Packed cargo weighs more than unpacked cargo so if drivers were able to pack double stacked cargo if they wish then they would be effectively increasing the difficulty of that haul and likelihood that the truck they are using will flip over or suffer engine power issues in exchange for the reward of having to make less trips. 

Basically turn overloading cargo into something that is officially supported and even intended. It’s a balance of risk vs reward. 

And of course drivers can always keep overloading unpacked cargo as they do now if they wish, so it wouldn’t prevent anyone from doing it the old way if they wanted.