i know you put these two pictures together because of the lines, both those on the ground and the "do not cross line" here. once again, the mathematical mind ventures into the underlying grids and structures of the reality realm; as is your lifetime's speciality ;-)
on a side note, isn't it LOATHSOME so see all these nice street crossings being transformed into roundabouts with ugly heaps of mounts in the middle? a street crossing, in former days, was a most lively place where people of all directions met; producing heightened awareness of each others presence and potential to crash into each other; nowadays, at the center of these crossings there is a completely DEAD space, with bored, stressed and mindlessly unaware people circling in and out of it. it may be more safe, but it also makes people more stupid.