There are people who do that now. I’m not an expert but I know there is specific DOT training for exactly that purpose. By regulation the waste is packed into a specifically strong cask that has been tested to withstand being dropped, lit on fire, etc. Good luck breaking one of those open.

https://robateltech.com/transportation-and-storage-casks/

Found this in a quick search. If you pay people enough they will do it. Liability is owned by the people sending the shipment.

https://cleanmanagement.com/blog/understanding-the-cradle-to-the-grave-waste-disposal-system/