Currently with cars you need green-red periods. But some researchers are considering scenarios, where in the future the cars just reserve the intersection for a few seconds and then pass through. That would be a lot of flickering between green and red.
There are scenarios and simulations where they show that we can get a lot more (fuel and time) efficient if we just let cars pass by each other in these reserved time windows. In many of these scenarios cars just go over the intersection at full speed during their reserved time windows.
NOTE: I am just reporting on what I know other researchers are currently investigating and proposing. I am not saying I think this is a good idea. At least I would consider this a security nightmare, because hackers could very easily have cars crashing into each other at full speed. Also I would be very very worried passing through an intersection behind an autonomous car and just trusting that this car not only reserved their window, but also reserved some additional time for me.