Round abouts, peanuts, uncontrolled, yielded, modal filtered, raised, edged, sunken, and more.

There are a lot of ways to give clear cues to all road users on what to do, and how to do it, without relying on signage. Traffic lights in particular are extremely low throughput; their primary advantage is allowing vehicles to drive really fast between intersections, so they are great for roads/highways but not for streets.