Why is there a standard for the placement of training linen wagons?

Because this is the hotel hygiene management regulations.

The linen bag is hung on the coupler, and the left side is used to collect towels and the right side is used to collect sheets. Empty the linen bag at the end of each shift and clean the inside and outside of the linen bag. Do not hang garbage bags on the linen cart, and put four buckets on the pedal of the linen cart to keep the cleaners with enough clean chemicals. Put the linen into the frame according to the regulations. Linen and supplies are complete and tidy, and cleaning and sweeping tools are placed on both sides.

At the same time, garbage bags and rubbish evacuated from the house should not be placed in linen bags or in other parts of the car. You can't put the drawn linen on the guest's belongings. The height of dirty linen is higher than that of linen bag. You must push the linen cart back to the workshop and unload the dirty linen.