High-visibility clothing is a good idea, right? If you slap some reflective bits on your clothes and go out for a walk at night, any headlight beams that land on you will be reflected back at the driver, making it easier for them to see you. It works on human drivers, but what about active safety systems – do they “see” a pedestrian’s reflective clothing, and does it help the system detect the wearer? According to recently published testing by the Insurance Institute for Highway Safety, pedestrians wearing reflective clothing at night might actually be less visible to some vehicles’ automatic emergency braking systems than if they were wearing non-reflective light-colored clothing, or even all-black outfits in some cases. That doesn’t seem good.
To see how pedestrian-detecting automatic emergency braking systems respond to various types of clothing, the IIHS used three compact crossovers from the 2023 model year, a Honda CR-V, a Mazda CX-5, and a Subaru Forester. Environmental illumination levels of zero lux (pitch black), 10 lux, or the federally recommended 20 lux of roadway illumination were tested, along with various garments. All tests were performed at 25 mph, with the dummy traveling across a crosswalk. While the Subaru performed extremely well, many of the other results are concerning to say the least, considering reflective clothing is supposed to be safer at night.
If it’s dark out and you’re being approached by a Honda CR-V driven by someone not paying attention, you might be better off wearing black clothing than a highly retroreflective jacket. IIHS researchers found zero speed reduction for the dummy wearing a reflective shell jacket under all lighting conditions. Meanwhile, the black outfit clocked speed reductions of nine percent in 10 lux illumination and 39 percent in 20 lux illumination. Still not great, but better than being hit at a full 25 mph.
The Mazda CX-5 fared better, shedding more speed when the dummy was wearing a fully reflective jacket than when the dummy wasn’t, but its system is not without blind spots. The IIHS also tested clothing with reflective strips, like you might get on workwear or dark-colored jackets and sweatpants designed for runners, and the results across all cars weren’t optimal. As the IIHS put it:
“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,” said study author David Kidd, a senior research scientist at IIHS. “Unfortunately, the moving strips didn’t have the same effect for the pedestrian AEB systems we tested and probably confounded their sensors.”
For the dummy wearing clothing with reflective strips, the Mazda CX-5’s automatic emergency braking system didn’t shed any speed at all regardless of lighting conditions. It’s the same deal with the Honda CR-V, no speed reduction through automatic emergency braking whatsoever. Even the Subaru Forester, which otherwise aced the testing, showed an uncharacteristic dip in performance when it didn’t come to a complete stop for the dummy wearing the clothing with reflective strips in 10 lux lighting conditions. This is particularly weird when you consider the Forester came to a complete stop under all lighting conditions when the dummy was wearing black clothing with no reflective properties.
So what’s going on here? Well, different manufacturers use different algorithms and sensing suites for their advanced driver assistance systems, but they usually consist of both radar units and cameras. The exception here is Subaru. Its Eyesight system is vision-based, relying solely on a pair of stereoscopic cameras. It’s possible that Eyesight is just better at processing images than some other systems because it doesn’t have radar to lean on, but that’s merely a hunch. As of right now, IIHS researchers don’t know why clothing with high-vis strips may be invisible to both the Mazda and the Honda, writing:
It’s not clear why the Honda and Mazda systems struggled with the reflective strips or how many other systems might have trouble identifying pedestrians wearing this type of clothing. However, the lapse is a concern, considering the number of roadway workers and emergency personnel who use similar garments to mitigate risk when they’re working on the road. Further research is needed to determine how crash avoidance systems respond to the specific safety equipment used by such workers.
As of right now, only one thing’s certain, and we’ve repeated it time and time again: Advanced driver assistance systems including automatic emergency braking are not substitutes for attentive drivers. Eyes on the road, people. Driving is serious business, and lives are quite literally on the line.
Photo credits: IIHS, Subaru
Top graphic:Андрей К/stock.adobe.com
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I work with a lot of people who work roadside doing maintenance and emergency response and almost all of us have come to realize that it doesn’t matter if you paint all your equipment yellow, put reflective stripes all over them and have all the blinky lights and cones, the general public will hit you no matter what.
Having been surprised by people in dark clothing when I leave in winter AM, I now keep a light hi-vis vest under the seats. My cars are 20+ years old and shit happens. If it does, I want to be visible.
-This study surprised & saddened me as people who have these safety systems can come to rely on them too much
This is unexpected, but if I have to choose, I’d rather be visible to a human driver than their last-resort emergency braking.
Ok, I think I know what’s going on here.
Humans confronted with novel situation focuse attention on it and tries to resolve it. Conspicuousness is a benefit in this situation.
Software confronted with novel situation either rejects it as noise, or focuses attention on it and goes into some default error mode, Conspicuousness is a liability in this situation.
That said, in NYC, the higher ranking police officers, the ones who wear the white shirts in nice weather, wear these black raincoats with reflective stripes that when it is raining heavily. It makes them look exactly like the stripes and crosswalk makings on the pavement rendering them invisible. And they just love to step backwards into traffic after talking to policemen that they are supervising.
I often see little white reflectors all over the place on the country roads locally, it is a mailbox, guiderail or deer’s eyes?
Perhaps reflectors that were formerly glued to the road then broke free? Got lots of those here. Beck when we were more fastidious about picking up stuff of the side of the road I had a couple buckets of them. Then we sold the farm and the new owner lets stuff pile up. There is a sofa and a speedboat on the side of the road now.
Retroreflection from a deer’s eyes is pale green. Road reflectors are white or red. Handy to know.
The real question here is how those systems were not tested by the manufacturers to make sure they stopped for people in clothing commonly worn by pedestrians and road workers?
And an even better question is did they do that testing, find these results and just not care?
Testing cost money, saying your AEB system is good is free.
God help us when the Feds mandate all new cars have AEB.
Just going to throw out I hate my companies new uniforms. Basically all black, with some reflective stuff thrown on. We do a lot of work at night. So the reflective stuff helps people with lights, but what about when I’m somewhere with low to no lighting.
I’ll throw in that I just encountered a new paint job on NC HP cars. They look all black, but shine headlights on them and the whole side turns while with the NCHP logo and lettering visible.
Ah, the road pirates. I call those “revenue generation units”. At least those actually reflect. There are some PD’s near me that have blacked out cars with non-reflective lettering.
With regards to actual people driving cars, it doesn’t matter how brightly coloured your shirt might be: you might as well wear black.
The only thing that gets actual people to see you at night are lights & reflectors.
Perhaps this finally answers the question: why do most winter clothes not have reflective bits on them when it’s most likely to be work with shorter days?
That is a good question since a lot of Nordic ski gear does have reflective stripes. I think this is so the Pistenbully or snowmobile doesn’t run over early birds since skiers are rarely on or near passable roads.
Wondering if this is why that Tesla on auto-pilot rammed into a fire truck, they’ve got reflective stuff all over them so you know…they don’t get hit.
While initially surprising, on further thought I’m not shocked. I’ve come up behind runners wearing reflective strips a few times and the patterns they use do not immediately make you think “human”. As a thinking being I recognize that something is there and take appropriate measures, but it has taken me a few seconds to figure out what I was looking at.
I am surprised the LIDAR systems get confused though. I wouldn’t expect them to be affected by visual anomalies like reflectors, but maybe the LIDAR signal also gets reflected back more intensely?
That would cause positives, one would think. Perhaps it deflects or scatters the LIDAR, rather than reflecting.
I commute by bicycle on unlit narrow country roads. The other cyclists at work complain about near misses from cars all the time despite wearing “hi-vis”. What they actually wear is usually all black, with maybe a stripe or logo of something reflective or fluorescent.
At night they look like a couple of dots. Small flashing rear lights don’t help much either as you can’t track the movement.
I wear an entire jacket of reflective material, plus reflective gloves and hat. In daylight I wear long sleeved roadworker spec hi-vis. It’s the shape of a person, you don’t have to work out what I am.
The near misses from cars have reduced a lot since I started doing this a few years ago.
A side benefit is that people are nicer to you when you aren’t dressed as a cyclist.
Flashing bike lights are a bee in my bonnet. Yes, they do draw your attention to the cyclist (and probably help the battery life), but usually the gaps between flashes are too long, which makes it hard to get a read on exactly how fast they’re moving and in which direction.
Humans can normally see something for only a fraction of a second and get an idea of where something is, how fast it’s moving, it’s direction, and whether we’re going to crash into it. The flashing bike lights just aren’t on long enough to give you that information.
Some have different settings. I typically keep mine in the “slow” flash mode, the “fast” flash is almost like a strobe, I assume that would be annoying or even dangerous for drivers.
As a cyclist, your often damned if you do, damned if you don’t. I used to road cycle a lot for fun/exercise but have mostly given that up due to too many close calls. I stick to the woods on my mountain bike. Even though I’ve broken a few bones MTB’ing, it STILL feels safer.
When you’re off road you’re managing your own level of risk, whereas on the road it’s in the hands of hundreds of people you’ve never met, several of whom think Facebook updates are more important than trying not to kill you.
I’d much rather MTB than ride on roads. All my bikes are MTBs and I’ll always divert to a trail if I’m passing one. I still ride on roads but there are a lot of types of road I won’t go on because it’s just too dangerous.
At night I use two lights on the back of the bike: one flashing for attention and one nice big constant light (that also lights up my translucent mudguard).
On the front I have a big bright headlight and another light pointing down to light up my forks and front wheel. With no other light source it’s obviously a bicycle.
But I still got hospitalised last year because a driver “didn’t see” me.
Oh yeah, these systems are great.
Can’t personally attest to the effectiveness of braking systems to detect pedestrians, but I can tell you that no automated high beams work for shit when it comes to not blinding walkers and runners. Not only do they not dip the lights for pedestrians, they frequently flash them on and off when reflective road signs fool them. Wouldn’t surprise me at all if reflective strips on clothing don’t cause high beams to rapidly cycle on and off as a moving pedestrian presents a constantly changing light pattern. The worst I’ve ever encountered (and counted) was during one late night run along a two-mile straight beach road. The ONLY car on the road at the time started way down at the opposite end of the straight from me and in the course of approach switched it’s high beams off and on 27 times ruining my vision. I flagged the driver down and complained and he said he’d readily seen me because of my reflective vest and cuffs the whole way, but the high beams were automated and he couldn’t do anything about those. Now, I know that’s bull; either he was too lazy (or drunk) to switch off the auto hi-beam function or didn’t know how, or just didn’t give a shit. I’m thinking about running with a BB pistol to give me manual control over approaching headlights.
Now, now, Don’t start an arms race, BMW headlights have frickin Lasers!
Automated high beams have been having similar problems since the 1950s and the kinks still aren’t worked out
Well the car though you were a road sign, and thought there was no oncoming traffic. Then you moved, the car though you were a different road sign, rinse and repeat.
At least it wasn’t self driving and didn’t think you were on the near side shoulder. Then it might have crossed over and either gone off the road or tried to drive between you and the shoulder.
I don’t dip my high beams for pedestrians. I need them to see the pedestrians wearing all black who walk out in front of me. I get that it’s annoying for non-suicidal pedestrians, I’m a pedestrian too, but if I don’t see them they die, and if they’re blinded by lights they can just not stare straight at them.
In the UK you can cross most roads wherever you like (jaywalking isn’t a thing here, because freedom), so you can expect any random pedestrian, runner or dog walker to step in to the road at any time. I also live in an area with no street lighting and a high density of morons.
Are they programmed to ignore the reflectors because they are just so prevalent on our roads? Bots dots, signage, mailboxes, guide rails, etc… all are reflective anymore. You and I can tell the difference because human.
Please click all pictures containing reflectors.
More likely programmed to divide reflectors into road markings, if they are in the road, or inanimate objects like signs, mailboxes, guide rails, etc.
For example, there is a stick figure of a pedestrian painted with retroreflective paint, helpfully distorted to make it easier for the driver to recognize. Does the car slam on the brakes and wait?
Yeah, don’t wear an upside-down triangle while jogging at night.
Why is it acceptable for a driver to delegate their responsibility to an engineer who makes something for a general purpose, while the driver needs to account for very specific situations where being wrong means someone dies?
Because we live in a dystopia somehow controlled by the dumbest group of rich elites that the world has ever known. I would have more faith in dynastic rulers that were the result of generations of inbreeding than any tech bro parasite or their software programmer puppets.
Well. This is concerning for me. My motorcycle riding jacket has reflective strips, so I wonder what these systems are going to make of me?
“Oh look – a Runway!
Time to land the plane…”
You should try some evening lanesplitting on a Saturday in Phoenix, preferably near the airport /s
So 2 technologies made to save lives, when combined, make it more likely to end lives? Sweeet…
We all remember those math problems. In this case it is the reverse. Positive x Positive = Negative. Once again automakers breaking math.