A colour code 'sunmaphore' to alert on skin cancer
27 June 2012 Last updated at 15:20 BST
New to the Colombian capital city of Bogota, the 'Sunmaphore' traffic light is designed to alert locals to the dangers of excessive exposure to sunlight.
The new device, of Chilean design, measures levels of ultraviolet-B radiation, which is particularly harmful to skin.
BBC Mundo's Arturo Wallace reports.