[adrianmonk]

As a pedestrian, I feel safer if there's a button to push!

Drivers can see the walk signal too. It serves as an extra reminder to look for a pedestrian. If it's on every time, then it conveys no information about whether there's a pedestrian this time.

For example, I'm standing on the northwest corner, facing east and waiting to cross. A car is also facing east and will be making a left turn across my path. Ideally every driver looks all around, so they'll see me 90 degrees off to their left, but in practice drivers tend to look in the direction they're going to be driving. This means their field of vision includes the walk signal but not me.

For that matter, I wouldn't hate the idea of expanding the button's functionality to advertise my presence even more. Like sticking a flashing "PEDESTRIANS PRESENT" light right next to the red/yellow/green light.

[alexlrobertson]

Buttons for pedestrian signals are great for safety. The point I was trying to get across is that in the proposed system, a pedestrian would never get a dedicated window to cross unless they push the button.