Check out this neat article about colorblindness and driving written by Crystal over at John’s Driving School:

“Over 200 million people are known to be color-blind across the globe. In the United States, 8% of the male population and 0.5% of the female population are color blind.

Eyesight is controlled by rods and cones. In the most basic sense, rods are responsible for our ability to see at night, while cones allow us to see color during the day. There are several types of color blindness that can make interpreting color difficult, but the most common involve the loss or limited function of the protan, or red cone, and the deutran, or green cone.  This is referred to as red-green color-blindness.

Anomalous trichromasy is a mild form of color deficiency when one or more of the three cones in the eye have altered light sensitive pigments who’s peak sensitivity is shifted. This impairment includes the most common types of color blindness, protanomaly and deuteranomaly, or red-weakness and green-weakness, respectively.

In people who have protanomaly, they see shades of red, orange, and yellow as shades of green. Conversely, people who have deuteranomaly vision sees those shades shifted towards the red end of the color spectrum.

As you might imagine, someone who has these vision impairments might have some trouble when it comes to differentiating the color of traffic lights. After all, traffic lights use red and green to tell drivers when it is safe to stop and go. In most countries, people who are color-blind are forbidden from driving all together, but in the United States, you are still allowed to drive, provided that you memorize the order of traffic signals and pass their driving exam. Fortunately, being color-blind is only a minor disadvantage, and one that you can adapt to living with.

Many color-blind drivers have trained themselves to associate the location of the light with the action that light dictates. For example, when a color-blind person sees that the bottom light is illuminated, they know that space is associated with the color green, which means “go” when driving. While this method is effective, it does require a number of steps before the brain can send the signal to actually do.

In 2009, a traffic light called the UniSignal was developed. This universal signal traffic light featured shapes as well as colors, so that a color-blind person might react more quickly when the light changed. When designers Ji-youn Kim, Soon-young Yang, and Hwan-ju discovered that the brain could interpret the signal associated with a shape much more quickly than the location of the signal, they designed the UniSignal traffic light. With this traffic light, a color-blind person could more accurately react to a change in the traffic light. In this way, the driver could imply associate a shape with stop, slow down, or go in one simple step rather than having to recall the order of the traffic lights, then the color in that order, then the meaning of that color.

These traffic lights have not been implemented in the United States yet, but there are still steps you can take as a color-blind driver to be safer on the roads. John’s Driving School invites you to step up to the challenge and make driving easier on yourself, whether you are color-blind or not, with the following safety tips.

  • Driving is more difficult at night, as your depth perception is more limited, your ability to distinguish color is limited, and your peripheral vision is more limited. Keep your eyes at their peak level of functionality and avoid looking at your phone or GPS screen, dashboard, or other car’s headlights for prolonged periods of time. Doing so can quickly fatigue your eyes, further limiting your ability to see the road ahead.
  • Certain glasses make you think you see better, but are actually blocking more light. Prescription glasses have anti-reflective properties that allow more light in, causing your eyes to adjust with the amount of sunlight rather than harshly as your vehicle moves in and out of sunlight.
  • Keep your eyes moving. Eyes at rest can become focused on one item and cause you to stare, missing an important road sign or a block in the road ahead.
  • Familiarize yourself with the location of the lights, and teach your brain to associate that location with the driving action (stop, slow down, or go). Through practice, you’ll be able to master your driving reflexes and safely maneuver the roads!”