A bed runner is a small, long piece of decorated cloth used to enhance the appearance of an otherwise plain bed.
While some prefer the look solely for aesthetic reasons and would choose it even if it were more expensive than traditional decorative bedding, the primary reason to use one in the hospitality industry is to reduce costs while keeping the room attractive.
Plain white linen not only costs less initially, it's easy and cheaper to launder than decorative linen.
Delicate or decorative fabrics often can't be bleached, and are easily damaged by mechanical washing machines - they simply don't last as long.
However, white blankets, comforters, and bedspreads are easy to clean and sanitize, don't fade, and still look good even after many washing cycles.
Plain white linen doesn't look as attractive as a fully decorated bed, though.
So a bed runner, which is small and only used for decoration, will enhance the appearance of the room while not requiring frequent laundering (only when obvious spots appear), and , being small, are easy and cheaply manufactured.
When they do need to be laundered, several of them can fit into a load, and that load can be run on a gentle cycle - the shear volume of bedclothes that must be laundered would prevent large bedspreads from this care, but the relatively smaller volume allows an occasional load of runners to take more time and perhaps a more expensive detergent process to clean without causing delays in resetting rooms.
Further, some hotel guests prefer clean white linen - which is easier to inspect and note stains or previous usage - to patterned linen for personal hygiene reasons.
Bed runners add touches of decoration while still exhibiting cleanliness for picky travelers.
travel.stackexchange.com/users/11355/Adam Davis
It's called a “bed runner“.
The main purpose is to make the bed look nicer and more stylish.
Where I live, it's become trendy (again?)
to put something similar on tables too (a “table runner”).
Earlier, it would be common in some countries to get a similar effect by covering the bed with a large blanket, folded at 2/3rd of the length to reveal another pattern.
travel.stackexchange.com/users/6669/Relaxed
I have no evidence of it, but I always thought it was there to protect the bed from dirty items like your luggage or your shoes.
Your luggage might be dirty because it touched the floor, so if you want to open it you put it in this piece of cloth and only that will get dirty and not the sheets where you'll sleep later.
Same thing to your shoes, suppose you want to lay down for a few minutes
and you're already dressed.
You can lay your feet on that piece of cloth and not in the sheets.
travel.stackexchange.com/users/24596/gmauch
The purpose of the bed runner is very simple: to protect the sheets.
So that when you lie on the bed with your shoes on, the shoes would not dirty the sheets.
It also looks pretty, but I think that's a secondary consideration.
It's not solely aesthetic.
travel.stackexchange.com/users/29461/Zack Xu
My personal epiphany towards the use of bed runner - is for people to jump onto the bed without removing their shoes.
Your legs (with shoes on) should then be placed within the area of the bed runner so as not the dirty your bed sheet.
travel.stackexchange.com/users/52715/derekastic
What is the purpose of the cloth across the bed? I see it at many hotels and it does not seem to serve any purpose other than make it look nice. Any idea what it can be used for?  Ps. The purplish elephant in foreground is towel. It looks nice!
What is the purpose of this cloth in hotel?
travel.stackexchange.com
<hotels><local-customs><sleeping>
travel.stackexchange.com/questions/47534
travel.stackexchange.com/users/29447/vasin1987
A bed runner is mainly there to make an otherwise plain bed look nicer and more stylish, although it may also protect the bed from luggage and shoes placed on it. Bed runners are pieces of cloth used as decorative items to make the bed look attractive. However, some people believe they may be to protect the sheets when guests put their shoes on the bed.
A bed runner is a piece of cloth that enhances the appearance of the bed. A bed runner is to protect the bed and sheets when guests put their shoes on the bed.