In self-service cafeterias across schools, workplaces, and other institutions, the metal rails positioned along serving counters to guide customer trays underwent regular maintenance.
After each serving period, these rails were wiped with cloths to clear away food residue and moisture. At regular intervals, a thin layer of lubricant was applied to the rail surfaces, allowing trays to glide evenly.
Such wiping and lubricating no longer takes place.
The rails stay fixed in their locations along the counters. Trays continue to rest on them and advance through the line as customers select food.
This arrangement exists with the upkeep of the tray rails absent.