This drill idea is from Phil Burden in SC.
If your out or on your way back from a run and see a gasoline tanker making a delivery at a filling station, stop and ask the driver if he has any time to review some of the parts of the tanker.
Most of the time the driver will be willing to go over the safety shut-offs, valves, compartments, and contents he is carrying.
The same drill can be applied if you come across a LP truck.
Pass it on!