This is just a weird idea. They can’t possibly expect people to buy a specific pedestrian safety device and carry it. They also can’t expect it to work reliably on the already congested and prone to being obscured and reflected.

It would make sense to integrate this as a feature to cell-phones, although…. considering that cell-phones constantly emit their own signals, why not devise a receiver that isolates existing cellular signals by proximity and direction? That would be an input to an overall system that can composite data from various sensors into much more decisive don’t-hit-me feedback to the driver.