Genius

the lights are always going to be in the same spot
im colorblind and i know greens on the bottom, yellows in the middle, reds on top

Have the word "GO" or "STOP" where the countdown would be, depending on if its red or green

Aren't colourblind people just affected when colours are contrasted?

No, the most common is red/green just becoming mushy brown color and not being able to tell the difference between them.

I see. Thanks for the info

But, red for them, is always the same color right?
I mean, they dont see all in grey, they know wich color is green and wich one is red, but on their on espectrum?

No, both red and green are the same color. Meaning they wouldn't be able to tell which hourglass is counting down.

So, 2 things i have to say:
Arent there many degrees of colorblindness?
and, Are you a colorblind person to say such a thing?

one of my teaher's could see reds and greens but not purples and blues. so i would say that there are different degrees and visible parts of the color spectrum in colorblindness

1. Possibly
2. Not at all. I've known a couple in my life.

And all of them claimed there was absolutelly no diference between green and red?

The one's I've known, yes. It comes out as a muddy brown color.

Hum, my colorblind friend sees red as purple, and green as a blueish green
So i suppose that yes, there are different degrees on that matter, and the more severe ones shouldn't be allowed to drive

They're allowed to drive, but only can use the position of the lights (red on top, green on bottom) as their reference. This hourglass method wouldn't let them drive.

maybe, keep positions, change to hourglass?

how many? 50?

exactly my tought, thanks anon :D

God damnit, Anon. Color blind people can only tell which light is lit up because of the placement. If they all look the same this would be a problem.

Have the word "GO" or "STOP" where the countdown is when the light is yellow would be, depending on if its red or green

I swear im the only person to post this every time this picture comes up

Think of all the jobs it could create. People constantly checking and repairing them?

but if they were color blind then couldn't they just as easily think it was the wrong color and try to drive through a red hourglass thinking it was a green hourglass? Hmmm?
Theres a reason that the syestem of 3 lights hasn't changed since its invention. If it aint broke why fix it

Have the word "GO" or "STOP" where the countdown would be, depending on if its red or green

color blind issue solved

untrue all the lights in my city are timed

First of all, not all lights change based on traffic flow. Many cities have lights that run on timers all of the time, and many intersections switch between timer and sensor at different times during the day. So, these lights would work for the timed lights.

Secondly, the purpose of these lights doesn't have to give the driver an idea of ho long he'll be waiting at a red light from the beginning of the red light. The "sand" could speed up or slow down depending on the traffic flow of the cross street. The point is just to give the driver some visual representation of how long he'll be waiting. It doesn't necessarily have to predict how long the light will remain it's current color from the moment that it changes.