Take, for example, the bit of nonsense above which is to be found at the end of a short footpath down the road from where I live. The total length of the path is no more than twenty yards, but at either end, great brush-fulls of white paint are daubed all over the tarmac. The precise meaning is unclear : something to do with bicycles been limited to one side of the path. The triangular shape on the right seems to suggest that if you wish to push your bike to the left you should pass to the left of the triangle, whereas if you are turning right you should keep to the right. The big concrete post in the middle is designed to knock you off your bike. They must have large, industrial-scale stencils for such creations and the "artists" must be paid on piece rate.
Can such work ever be considered art. I am not sure. But I might just frame the photo I took of the painting spree as it continued into the main road.