The simplest traffic light is a four-way intersection; one without any detectors, cameras, or outside intervention of any sort. A signal timing plan is the most basic way to control these lights.

Beryl Many in Houston don't know how to do this one, simple thing while driving Major intersections with traffic lights out are creating confusion, chaos and accidents on the road.

It relies on a single technological trick — an ingenious hack of the traffic ecosystem. When the light changes, it's not red, or yellow, or green. It's white — and white means: "Robots, go!