In the express lane . . .
You know how they set up express lanes in supermarkets by the number of items you want to buy? And how there's always one statistician in the store who has an overflowing cart but insists that his purchases are actually below the limit because of the statistical mean?
It would be a hell of a lot easier and fairer for all concerned to replace those aisles with ones that ban carts, bags and baskets. If you can carry it to the register, you can buy it.
There'd be entertainment value as well.