Reflective Risks: High-vis clothing may be invisible to crash prevention sensors

Toronto, Ontario ⁠— High-visibility clothing may be invisible to automated crash prevention systems, according to a new study from the Insurance Institute for Highway Safety. 

The study investigated the effects of conspicuous clothing and increased roadway lighting on the performance of the pedestrian AEB systems installed in three 2023 models⁠—a Honda CR-V, Mazda CX-5 and Subaru Forester. 

Researchers conducted multiple trials with an adult-sized dummy clothed in a black sweatshirt and pants, a retroreflective jacket with black sweatpants, the black sweatshirt and sweatpant with retroreflective strip added on the dummy’s limbs and joints, and a white sweatshirt and pants. The retroreflective strip pattern used was similar to the one seen on roadway worker outfits, although their safety gear is generally bright orange or yellow rather than black. 

The tests were run at 25 miles per hour (40 kilometres per hour) with no roadway lighting, with 10 lux of illumination in the crosswalk or with the federally recommended 20 lux of illumination in the crosswalk. The dummy crossed the track perpendicular to the path of the vehicle in all scenarios.

The CR-V and CX-5 hit the dummy in 84 percent and 88 percent of the test runs, respectively, while the Forester avoided a collision in all but one trial. Neither the CR-V nor CX-5 slowed at all when the dummy was wearing clothing with reflective strips that articulated its limbs. Otherwise, the performance of the Honda and Mazda crash avoidance systems varied.

When the dummy was dressed in black, both vehicles slowed substantially when using their high beams—a test that was only conducted with no roadway illumination. Using their low beams in those same conditions, the CR-V failed to slow at all and the CX-5 reduced its speed by less than a third. Both vehicles did much better with 20 lux of additional light.

A pedestrian mannequin dressed in white clothing (upper left), black clothing (upper right), black clothing with retroreflective strips (lower left) and black pants with a highly retroreflective jacket (lower right).

For all the other types of clothing, the vehicles were only tested using their low beams.

When the dummy was dressed in the reflective jacket, the CR-V didn’t slow in any of the trials, regardless of additional roadway lighting. In contrast, with no roadway illumination and with 10 lux of added light, the CX-5 slowed much more than it did when the dummy was clad in black. But with 20 lux of added light, it performed worse with the dummy in the reflective jacket than when it was wearing the black outfit.

When the dummy was dressed in white, the CR-V didn’t slow at all with no added roadway illumination but notched up its best performances with 10 and 20 lux of added light. However, it did better with 10 lux of illumination than with 20 lux. The CX-5 performed better than it did with the dummy in black but not as well as with the dummy wearing the reflective jacket. It also slowed less with increased roadway illumination when the dummy was wearing white.

In contrast to the two other vehicles, the Subaru came to a complete stop without hitting the pedestrian dummy in every trial except one run in which the dummy was wearing clothing with reflective strips and the roadway was illuminated to 10 lux. Even in that run, it slowed by more than 80%.

“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.”

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.

“This is a worrisome blind spot,” Harkey said. “To make good on their potential, pedestrian detection systems have to work with the other commonly used safety measures.”

“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 recognize.”

Click here for more information on IIHS’s study.

The post Reflective Risks: High-vis clothing may be invisible to crash prevention sensors appeared first on Collision Repair Magazine.

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