Road-side tradies might want to take a second look at their high-vis gear because new research suggests it could be making them less visible—at least to some vehicle safety systems.
A study from the Insurance Institute for Highway Safety (IIHS) in the U.S. has found that certain high-visibility clothing doesn’t always register properly with autonomous emergency braking (AEB) systems—the tech designed to detect pedestrians and stop cars automatically.
Even more concerning? Some of these systems performed worse when faced with a dummy wearing reflective strips than when the same dummy was dressed in all black.
Safety systems struggle in the dark
AEB technology has been a game-changer in reducing pedestrian crashes, cutting incidents by around 27 per cent overall. But according to the study, its effectiveness drops drastically after dark—when most fatal pedestrian crashes actually happen.
“These results suggest that some automakers need to tweak their pedestrian automatic emergency braking systems,” said IIHS president David Harkey.
“It’s untenable that the clothes that pedestrians, cyclists, and roadway workers wear to be safe may make them harder for crash avoidance technology to recognise.”
To test the systems, the IIHS used three 2023-built vehicles—a Honda CR-V, Mazda CX-5, and Subaru Forester—and ran trials with a pedestrian dummy dressed in different outfits:
- All black
- A retroreflective jacket with black pants
- All white
- Black clothing with reflective strips placed on the limbs and joints (similar to typical road-worker gear)
The trials were conducted at 40km/h in three lighting conditions:
- No street lighting
- Dim lighting (10 lux at the crossing)
- Brighter lighting (20 lux at the crossing, the federally recommended level)
The results? Pretty alarming. The Honda CR-V and Mazda CX-5 hit the dummy in 84-88 per cent of tests, failing to slow at all when the dummy was wearing black clothing with reflective strips.
In contrast, when the dummy was dressed in all black with no reflective material, both vehicles slowed significantly—but only when high beams were used. With low beams, the Mazda still reduced speed slightly, but the Honda didn’t slow down at all.
When the dummy was wearing a reflective jacket, the Honda CR-V failed to slow down in every test, regardless of lighting conditions. The Mazda performed better without street lighting but worse under the brighter 20-lux illumination.
The Subaru Forester performed the best, avoiding the dummy in nearly every scenario—except one.
The only time it failed? When the dummy was wearing clothing with reflective strips, under 10 lux lighting. Even then, it still managed to slow by over 80 per cent before impact.
Why is this happening?
David Kidd, a senior research scientist at IIHS, explains that reflective strips are meant to help human drivers recognise movement, but they confuse pedestrian detection systems.
“The placement and motion of reflective strips on the joints and limbs of pants and jackets allows drivers to quickly recognize the pattern of movement as a person,” Kidd said.
“Unfortunately, the moving strips didn’t have the same effect for the pedestrian AEB systems we tested and probably confounded their sensors.”
And this isn’t the first time high-vis clothing has been questioned. A 2023 study by QUT and Flinders University found that cyclists wearing safety vests or helmets appeared “less human” to other road users, potentially making them less noticeable on the road.
While these findings were focused more on the perception of other drivers rather than the safety systems under the hood, researcher Dr Sarah Collyer warned the findings raised alarm bells for tradies rocking hi-vis.
“Our study found that both males and females wearing ‘high-vis’ safety wear were consistently rated ‘less human’,” she said at the time.
“Does this mean people see road work crews, for example, as ‘less human’ and, if so, what does that mean for their safety?”
Car manufacturers claim to be already working to refine their AEB systems to prevent these failures. But in the meantime, it’s a wake-up call for tradies, road workers, cyclists, and pedestrians who rely on high-vis gear to stay safe.
With AEB systems becoming more common, ensuring they work with safety gear—not against it—will be crucial. As Harkey put it:
“To make good on their potential, pedestrian detection systems have to work with the other commonly used safety measures.”
