Colorblind at the Traffic Light
- Posted by Daniel Flück on February 6th, 2007 filed in Stories
I have a drivers license for more than ten years now. When I applied for it I didn’t had to take a color blindness test. This is maybe the reason why I have one…
The question most people think about when they hear, that someone who is colorblind and does have a drivers license is: “How do you know when to stop at the traffic light?” And they don’t stop thinking here but start to find a reason themselves.
People conclude that if you are colorblind you know, red is on top, green at the bottom and that’s the way colorblind people find their way through the traffic jungle. But that’s wrong.
Why is it wrong?
- The association between top and stop, bottom and go is to weak.
- The connection for deciding what to do is not fast enough.
- The thought needs to many steps. Light - top - stop is one step to much.
So what do you do if you are colorblind?
Colorblind doesn’t mean you can’t see colors at all. You can see colors, differences in hue, saturation and lightness. Maybe not as good as with normal vision, but you definitely have a broader vision than just black, white and gray. And because of that, people suffering from color blindness do see different colors at the traffic light. Some more differences, some less and maybe not the same difference in color as people with normal vision. But all you have to learn is which color you see relates to which reaction.
If you are colorblind you know this color means stop and that color means go. You don’t know the name of the color. You maybe can’t relate the colors you see at the traffic light with other colors in the nature. You even may give them other names. But you will always know the difference because you can see a difference.
If you are not affected by color blindness I suppose all this is hard to imagine. Have a look at some pics and help your imagination. Some pics are about Walk – Don’t Walk pedestrian lights, modulated to show different color vision deficiencies.
By the way, there are many traffic lights not only from top (red) to bottom (green) but from left (red) to right (green). If you would just remember the sides, you definitely would mix them up all the time.
February 6th, 2007 at 22:09
As a protanope, my main problem with traffic lights is just that the red light is so dim. I can easily tell green from red, and easily see the green light. But if I approach an intersection and the light is red, I sometimes have to search around to find where the light is. This is especially hard in a busy city intersection where there are a lot of other lights all over.
Interesting articles:
http://dx.doi.org/10.1007/BF00137452
http://www.hubmed.org/search.cgi?q=12135418
February 7th, 2007 at 9:20
Peter, I have the same ‘problem’. The red light doesn’t stick out that much and this makes it sometimes hard to spot it. Thanks for the interesting links. The experts don’t agree if you should exclude colorblind (specially red-blind) people from road traffic or not. Why don’t they try to find a solution for the traffic lights?
October 22nd, 2008 at 1:08
The new LED red traffic lights solve this problem (for me at least) because they are so much brighter. I can see the red LED traffic lights, even in bright sunlight, for blocks away. They really stick out. Old-style traffic lights, a bulb with a red filter, blend into the background and don’t look lit in bright sunlight.
October 22nd, 2008 at 20:33
My problem is with the red and yellow lights. From a distance, I cant really tell the difference between the two colors. This is especially dangerous for me when approaching a flashing red/yellow light as I cant tell which one it is until I am close enough to pinpoint its placement in the stack.