Ever wondered what those random things on the pavement mean?

Here is an article explaining what those weird things on the pavement are that you may sometimes see spray painted on the floor. This mainly applies to the UK. But, there may be a similar system in other countries. I found it quite interesting.

http://www.bbc.co.uk/news/magazine-25915468

 

That is a bit different that what I've see. From my little exposure to the outdoors I've noticed some spray paint on sidewalks and on roads. I'm not sure if there's any color coordination but most are white and arrows pointing to something. I've seen both red and yellow used to mark bumps or where a section is raised.