Remember that Laservision Softstop system from Australia? Designed to prevent truck drivers from slamming into tunnels too short for their vehicles, it's a water- and projection-based stop sign that's completely unmissable.
TikToker vfxhd has lifted the concept, without attribution, and correctly assumes they'd be an effective way to prevent phone-gazing pedestrians from strolling heedlessly into crosswalks:
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Of all the things out there that can kill you, smartphone distraction is the most unbelievable to me. But I've seen those supercut videos of people, noses in their phones, getting hit by cars; it's real, and I wouldn't be surprised if we eventually see these popping up in the future.