The 8808 Pavement Mystery

Walking up the road between Richmond and East Sheen tonight I noticed a paving slab with what looked like the number '8808' on it. Then another. Then another few. Then a whole block with each paving slab carrying the same set of characters. It might not be 8808, it might be 8088 and I'm reading them upside-down. Or it might just be shapes that happen to look like numbers. After a few hundred yards it stopped and the paving stones went back to normal.

What can it mean?