Japanese Kyushu Sangyo University’s professor Taro Ochiai has developed LED traffic lights which can be seen by colour-blind drivers.

Prof Ochiai starts to study LED application in 2003, when they first began to be used in traffic lights in preference to regular light bulbs. Sources has shown that colour-blindness affects around 8 per cent of males and 0.5 per cent of females, with most people with the condition experiencing problems differentiating between red and green. As a result , Colour-blind drivers reported that the LED signals were more difficult for them to discern based only on brightness as the visual indicator.

To solve this problem, Prof Ochiai has worked with lighting manufacturer Koito Electric Industries Ltd., to incorporate blue LEDs with four times the brightness of the other diodes in the shape of a cross through the red lamp.

According to the study, drivers with perfect vision will hardly notice the pink X that is set within the red signal, particularly from a distance, but red-green colour-blind divers are able to easily distinguish the contrasting blue X against a background that they perceive as being yellow. Research shows that the mark is clear even from a distance.

Prof Ochiai's new traffic light will help colour-blind drivers free from discern Obstacle. And it has recognized the 2011 Good Design Award for public facilities and equipment.

Currently, Japan is testing new traffic lights in the southern city of Fukuoka. A second month-long test is to be started in Tokyo before the end of February. Local authorities and the police are monitoring the progress of the tests and, as the manufacturing process is very close to how conventional traffic lights are made, the professor believes the improved versions could start to be installed in the near future.