Ways to Control Traffic
Some people think, traffic lights is THE ONLY way to control and regulate (manage) traffic flow.
For others, esp. those who have seen round-abouts or circles in European countries, know that in some cases round-abouts are a much superior alternative to traffic lights.
And some people who drive on Indian roads know that the first 2 methods don’t really work and they have a chaotic, completely unpredictable, yet self-regulating traffic system.
All 3 are valid ways to manage traffic under the given circumstances. Possibly there are other traffic control systems that I’m not aware of.