I will forever contend that these don't work on cary in particular because of poor sight lines. As a person who drives a small car, I can't see past the giant SUVs parked on both sides of the street, or the ones driving in front of, behind me, and to my immediate side. Between weaving between vehicles that are double parked with their flashers on, pedestrians using crosswalks, pedestrians crossing without crosswalks, people parallel parking, vehicles pulling out from side streets, etc, it's very difficult to spot somebody waiting to cross.

If you're in one lane with a vehicle in the other lane slightly ahead of you, you can't see somebody waiting to cross at all.