Never mind the article - this might be a good idea
It always struck me that the pedestrian lights were hard for the visually impaired to spot and decipher. Yes, I know there are audio signals, but at a busy junction they're difficult to hear.
Also, whether smart phone-impaired or not, you always look at where you put your feet, so ground level is not a bad place for flashing red.
Costly? Maybe. But you'd only bother at busy junctions. And injured humans are very expensive to fix.