Hmmmm - I never noticed it. But it's not one of my regular haunts....

My guess = This may be something to indicate a "No Parking & No Waiting" zone.

Or maybe, like the sick bay on HMS Victory, they just painted the roadside red to hide all the blood?

Next time I find myself in the bitter valley, I'll look out for some road signs that might explain it. Someone else here is likely to beat me to it.