From Family Handyman · Alex Shoemaker · · 50s
Traffic Light Yellow Borders Explained
Yellow borders on traffic lights improve night visibility and safety during outages.
In brief
Yellow borders on traffic lights improve night visibility and safety during outages. Yellow reflective borders around traffic lights enhance nighttime visibility and provide a visible stop cue during power outages. Originally reported by Family Handyman.
What Yellow Reflective Borders Mean
Yellow borders around traffic lights are reflective strips attached to black backplates that catch headlights for better nighttime visibility.
“This treatment is recognized as a human factors enhancement of traffic signal visibility, conspicuity, and orientation for both older and color vision deficient drivers”
Safety During Power Outages
The borders provide a visible stop cue for drivers during power outages when traffic lights would otherwise be dark.
“This countermeasure is also advantageous during periods of power outages when the signals would otherwise be dark, providing a visible cue for motorists to stop at the intersection ahead”
Safety Benefits
A 2005 study found yellow reflective borders reduced crashes at intersections, making them a proven safety measure.
“A 2005 study found that adding yellow reflective borders reduced crashes at the intersections researchers examined”
Why Not All Traffic Lights Have Borders
State and local agencies decide where to install yellow reflective borders based on visibility needs and cost considerations.
“Federal traffic safety standards allow yellow reflective borders, but don’t require them at every intersection”
The headline
Yellow reflective borders around traffic lights enhance nighttime visibility and provide a visible stop cue during power outages.
