Question: What is the purpose of a traffic circle?
Answer: engagement with pedestrians, encouraging deference towards them
reduced driver confusion associated with perpendicular junctions and reduced queuing associated with traffic lights
reduce the likelihood and severity of collisions
potentially leads to less pollution
Disambiguated questions and answers: question: What is the purpose of a traffic circle in terms of safety?
What is the purpose of a traffic circle in terms of how it establishes a flow of traffic?
What is the purpose of a traffic circle in terms of environmental benefits?
answer: reduce the likelihood and severity of collisions greatly
traffic is permitted to flow in one direction around a central island
potentially leads to less pollution
Natural Questions answer: traffic calming
aesthetics (from the Wikipedia article "Traffic circle")