How Colour-Blind Drivers Can Read the Road Safely
Last reviewed: 2026 · Driviology Road Safety Education Team
Quick Answer
Colour-blind drivers can reliably read traffic lights by their fixed position - red on top, green on bottom - rather than relying on colour alone, and most forms of colour blindness do not prevent licensing in Ontario.
Colour vision deficiency affects a meaningful share of drivers, most commonly making it harder to distinguish red from green. Traffic systems are designed with this in mind.
Reading Traffic Lights by Position
Standard traffic lights are always arranged in the same order — red on top, yellow in the middle, green on the bottom — specifically so drivers can identify the signal by position rather than colour alone.
Other Cues Beyond Colour
Brake lights, turn signals, and warning signs also rely on shape, position, and flashing patterns in addition to colour, giving colour-blind drivers multiple ways to confirm what they are seeing.
Licensing Requirements in Ontario
Most forms of colour blindness do not prevent someone from getting or keeping an Ontario driver’s licence, since vision testing focuses primarily on visual acuity rather than colour discrimination.