In answer to a couple of questions:
As far as loading the board, wkmac is right. PAS will tell the preloader where to place each package (what car and where in the car). It will automatically count stops and provide information to DIAD so that the board is automatically loaded.
This is running in many buildings right now. Gainesville Georgia was the test site for all this. Ask the drivers what they think. They actually made a video that went to the board about the project.
Second, decisions on how DIAD IV will look and feel took into account what drivers thought. Many drivers and managers were interviewed and tested prototype units. They gave feedback on size, weight, keyboard, layout, etc.
Certainly, 300,000 people can't be interviewed but UPS tried to get feedback from those that "will actually have to use the diad each and every day"
Jack