Every year in the USA, nearly 700,000 car accidents are reported by police as stop sign violations, accounting for 2/3rds of crashes.

Stop signs are mostly red and for the 4.5% of people that are color blind, they are less visible than other road signs. Occasionally on stone and foliage backgrounds against the sun, in peripheral vision, red signs can represent many seconds of delay in awareness when arriving at a blind junction and can be dangerous.

Less people would crash if all panels should have yellow, cyan and magenta regions on them too, some designs that are visible to color blind and ordinary people.

Would it be possible to take the national/EU transport authorities to court to complain about risking lives and discrimination? Am I missing something?

  • 1
    If you have a driving license and are regularly driving a car, then your “several seconds of delay in awareness” is probably enough to take your license away, so be careful. On the other hand, if you failed your driving test because of this, go ahead.
    – gnasher729
    Mar 23, 2020 at 14:48
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    Stop sign is octagonal for a reason. And it’s red with huge white letters. I very much doubt that a colour blind person cannot see and identify it. If there was another octagonal street sign with large white writing on green or blue background that would be different. But all you need to see is “large octagonal sign at a crossing, with large white letters on dark background”.
    – gnasher729
    Mar 23, 2020 at 14:49
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    red-green blindness doesn't mean that red signs are invisible, just that distinguishing red hues from green hues is impossible or difficult. E.g. a dark red sign could be difficult in front of dense foliage. But the red and white used on traffic signs has good contrast, so no problem. Small colored dots don't help at a distance. There is also blue-yellow blindness and total color blindness!
    – amon
    Mar 23, 2020 at 16:32
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    Guys, this is not the forum for discussing the physiology of colour blindness. Let’s accept that there are some people who have difficulty in distinguishing stop signs and deal with the legal implications of that.
    – Dale M
    Mar 23, 2020 at 20:06
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    Your question makes it sound like you're imagining a problem, your comments clarify that this is a real problem for some people. However, I also have a color deficiency, but for me it's just normal: traffic signs aren't harder to see as I have no reference point for “normal”. I guess I experience parallax effects as more important for spotting signs than their color? Of course red-blindness is more problematic than green-deficiency here. Note that if you weren't able to see the signs, one possible conclusion is that you're unfit to drive.
    – amon
    Mar 23, 2020 at 20:08

1 Answer 1


Would it be possible to take the national/EU transport authorities to court to complain about risking lives and discrimination? Am I missing something?

Transport authorities are not responsible for the design of traffic signs. The designs are part of traffic laws, typically based on the Vienna Convention for Road Signs and Signals. To force a change to the designs, other than lobbying for changes directly, there would be a legal challenge on the grounds that these designs are unconstitutional to a degree that outweighs the benefits of uniform signage across countries, or other legitimate reasons in favour of the status quo.

This will be difficult, as traffic signs already convey their information in redundant manner, combining both overall shape, high-contrast symbols, and the colours itself. Thus, even a colour-blind person is able to read the signs.

Your argument is slightly different, that colour blindness makes it more difficult to spot the signs. This ability varies from person to person, but even people with normal vision can have difficulty spotting and understanding signs, regardless of their colour (or even because a color!). Here, there might be another opportunity for a legal attack: that signs have been mounted to close to each other or that they aren't visible enough due to their surroundings. But simpler sign locations would benefit all traffic participants, so I don't think focusing on the colour-blind angle would provide additional weight.

In any case, the status quo is: if you are unable to safely see traffic signs, you are unfit to drive. It is reckless to drive in a manner that prevents you from reading signage, e.g. if you are driving too fast. This is not necessarily an illegal form of discrimination.

  • I've added a reference stating that 2/3rds of car crashes occur at stop sign violations in the USA. It isn't about missing every stop signal, it's about the thousandth stop sign which is poorly lit, a bit grey, against a similar colored background in a busy street. I haven't ever missed a stop, i have 19/20 vision, I sometimes i see stop signs annoyingly late. Another conclusion is that red signs are less visible to people with impaired red vision. it's not unreasonable. I've been on the road for 20 years and I've had 2 collisions, both times i was rear ended and the car was barely scratched, Mar 23, 2020 at 20:55

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