Big problem with hi-vis revealed
New research suggests some high-visibility clothing may be almost undetectable to some vehicle safety assist systemsIn a strange turn of events, the reflective high-vis attire donned by pedestrians, road workers, motorcyclists and bicycle riders alike, could be doing more harm than good.
A new study has revealed the poor performance of autonomous emergency braking (AEB) systems in some modern cars after dark, when the technology has been shown to struggle to detect the high-visibility materials often used to help vulnerable road users stand out.
The new findings come from the Insurance Institute for Highway Safety (IIHS) in the US, which found that while AEB systems in general reduce the rate of pedestrian crashes of all severities by 27 per cent, the effect of pedestrian AEB on crash risk on dark roads is negligible.
Furthermore, test results showed the performance of some AEB systems was worse when exposed to a test dummy wearing reflective strips after dark than when it was dressed purely in black clothing.
The major problem, the IIHS added, is that most fatal pedestrian crashes happen at night.
“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.”
Tweaking safety systems is exactly what manufacturers are working to address, says the IIHS, which used three 2023-built vehicles – a Honda CR-V, Mazda CX-5, and Subaru Forester – in its latest study to analyse AEB performance across several scenarios.
Across multiple trials at speeds of 25mph (40km/h), an adult-sized dummy was dressed in four different ways: a black sweatshirt and pants; a retroreflective jacket with black sweatpants; a white sweatshirt and pants; and a black sweatshirt and pants with retroreflective strips at the limbs and joints, said to mimic a typical road-worker outfit.
With the dummy moving across a staged pedestrian crossing, tests were conducted in three levels of lighting: with zero roadway lighting; with 10 lux of illumination at the crossing; and with the ‘federally recommended’ 20 lux of illumination at the crossing.
According to IIHS, the CR-V and CX-5 hit the dummy in 84 and 88 per cent of runs respectively, while neither slowed at all when the dummy was wearing the black clothing with reflective strips.
When dressed in all black, both the Honda and Mazda slowed substantially when using high beam headlights (but with no external illumination), but the same test using just low beam headlights saw the CX-5 reduce its speed by a third, while the CR-V failed to slow at all.
Both the Mazda and Honda reportedly performed much better in some tests with 20 lux of illumination at the crosswalk.
When dressed in a reflective jacket, the Honda failed to slow in any trial, regardless of lighting, while the Mazda slowed much more with no lighting and at 10 lux compared to when the dummy was dressed in all black.
However, with the pedestrian crossing lit up to 20 lux, the Mazda performed worse when the dummy was wearing the reflective jacket, compared to the all-black outfit.
The all-white outfit also produced mixed results, one of which saw the CR-V fail to slow at all with no roadway illumination, while producing its best results with 10 lux illuminating the crossing.
Meanwhile, the Forester avoided the dummy and came to a complete stop in all but one test: the one where the dummy was wearing clothing with reflective strips and the road was illuminated at 10 lux.
IIHS added that even in that single failed attempt, the Forester still slowed by more than 80 per cent before impact.
For the full results, visit iihs.org.
It’s not the first time hi-vis clothing has been in the spotlight, with a 2023 study by QUT and Flinders University finding cyclists who wear safety vests or helmets look “less human” to other road users.
Related: Compulsory high-vis for cyclists on the cards
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