The familiar red, yellow, and green of traffic lights weren’t chosen for their inherent visibility or logical progression. Instead, their origins are deeply rooted in the history of railways, where these colors had already established a critical safety code. Early railways used red to signify ‘stop’ due to its association with danger and blood, a universally understood color for warning. Green, conversely, meant ‘caution’ or ‘clear to proceed’ because it was a less intense color and thus less likely to be confused with red in dim light. The yellow signal was a later addition, introduced to provide a distinct ‘caution’ phase between green and red, preventing abrupt stops and mitigating rear-end collisions. This railway code, developed out of necessity and proven effective, was naturally adopted by the burgeoning automobile industry as roads became more complex and the need for standardized traffic control emerged. Thus, the colors we see every day at intersections are a direct inheritance from the steam engine era, a testament to how established safety protocols can transcend industries.
Adapted from: Motor1.com - Articles
