Dean Hoffman wrote

Ranchers and farmers know about these but for the benefit of city guys:
https://www.dailymail.co.uk/news/article-7394651/cows-JUMP-white-line-middle-road-cross-new-field.html
My parent's neighbors had a couple of the the actual steel version.
Horses walked right over them if I remember correctly.

Fascinating to watch these bullock teams being broken up
and loaded into trucks. They quite literally have very long
runs of just string which is used to keep them from straying
from the path between the cattle yards and the loading
ramp at the back of the trucks. I'll video it next month.
http://barellanclydesdales.com.au/