Letters, numbers and marks are intriguing.
They convey specific meaning to someone, in this case, something utilitarian and informative. But to those of us who arent' clued in on the use of this particular object or what needs to be conveyed by these numbers, it is just some foreign code. We know it means something, but just arent sure what.
And sometimes the coding is less obvious. Again, something is being conveyed here by someone to someone else. It's just not us. And again, we're not clued into the particular story, like a movie in a language we don't speak with subtitles we can't read.
But I sure like how it looks and makes me feel. I like the idea that there is a bigger story happening in the city. Collectively, randomly, converging, particular.