When a light goes down at an intersection, one of two things will occur. Either the system’s back-up response will kick in that everyone knows and understands or a new response will take shape.
In the case of a light going down the back-up response here is everyone waiting their turn, while they wait for the next person to go (on their right). The process isn’t perfect, traffic is slowed down, but it goes, it works and we can get by until the system comes back online.
The other option is, for someone to get out of their car and start directing traffic manually. Lanes are opened and traffic flows more quickly from A to B while C and D wait their turn.
There are pluses and minuses for both, in one scenario you are trusting the system, in another you are trusting the leader directing traffic.
Both can work, but you have to choose and can’t do both at the same time.