This may be the single most important piece of advice you get from this website.
Laugh if you want but this sign saved my neck (and the rest of my body) many times.
They drive on the bloody wrong side of the road in England.
Which means that every time you cross the dang street the dang cars are coming from the exact opposite direction you're expecting.
These signs remind you which way to look.
Thank you to local British city councils who make sure these signs are painted on the streets used frequently by tourists from countries where we drive on the correct side of the road.