If you’ve ever taken a road trip down south toward San Diego County, chances are you’ve noticed some glowing orange stripes mixed in with the usual white lane lines on the highway… And no, it wasn’t an illusion.
What started back in 2021 is now being implemented more widely. Caltrans’ program involves adding orange tones (the same color used in cones and construction signage) over or alongside the white lane lines, making them a much stronger visual cue than traditional white or yellow lines. These stripes are temporary and only used when drivers need extra alerting for special road rules, like reduced speed in construction zones.
How California’s orange highway stripes work
As civil engineer Rob Sanders explains on his YouTube channel Road Guy Rob, instead of painting over the old white and yellow lines, crews are adding orange alongside or before them. Two methods are being tested: one places orange next to each white line, while the other places orange just before the white line on southbound lanes, stacking it vertically to create contrast.
The idea is that the bright orange makes it much easier for drivers to see where they’re supposed to go. Currently, you can see the orange lines in San Diego County near Legoland, where a new carpool lane is being added on Interstate 5.
How orange stripes improve safety
According to Slash Gear, early survey data from this California pilot shows that over 83% of drivers said the orange lines made them more aware they were in a construction zone, about 72% reported slowing down, and nearly 75% found the markings easier to see at night than traditional cones and signs.
Even drivers who didn’t know the exact meaning still took the unusual color as a signal to be cautious. These results suggest the stripes are doing exactly what they’re meant to: improving awareness and encouraging safer driving in work areas.