Why Some Stoplights In Canada Feature Shapes Other Than Circles

Not everywhere around the world has a standard traffic light. Some places, like Japan, have blue in place of green, and North Carolina has even added a fourth light since self-driving cars were introduced. In Canada, the colors stay the same, but in some provinces, you will notice a big difference — the shapes aren't all circles. In Prince Edward Island, for example, the red light is a square, the yellow is a diamond, and the green is a circle. As PEI locals mention on Reddit, the reason behind this change is to accommodate people who live with color blindness.

According to the Cleveland Clinic, red-green is the most common type of color vision deficiency. By associating each color with a distinct shape, all drivers in PEI can distinguish what to do with such a unique traffic light, even if they cannot perceive the color clearly. This increases safety at intersections, reducing the likelihood of accidents caused by color confusion.

You'll only see these shapes on horizontal stop lights, which aren't as common as vertical ones, but they still prove to be helpful for those in need. In fact, on the Reddit thread mentioned above, many self-identified color-blind users say this is really beneficial. However, you won't find these traffic lights everywhere. Aside from Prince Edward Island, they are only found around the Canadian provinces of Québec, New Brunswick, Nova Scotia, and Eastern Ontario.

Canada only has these traffic lights in a few provinces, and some aren't even installed across the entire province, like in Ontario, due to traffic regulation standards. An Ontario local revealed that the Municipal Signal Co. invented the symbolic traffic light, and Québec used them for decades, making the horizontal configuration a standard installation. The other provinces listed seem to have followed Québec's lead.

Provinces that have primarily vertical lights don't need extra indicators, as many people know that red is at the top, yellow is in the middle, and green is at the bottom. According to the section on vision in the Prince Edward Island Driver's Handbook, "if you are colour blind, you will have to learn the relative positions of the traffic signal lights."

Placement is important, so when you have an uncommon, horizontally-shaped traffic light, the square, diamond, and circle shapes can help drivers to understand the actual signal. At the end of the day, these provinces are focused on safety first and foremost. Want to learn more about PEI — one of Canada's provinces with accessible traffic lights? See our feature on the seaside storybook village that's walkable, artsy, and serves up fresh seafood.