Why does green mean go and red mean stop?

About this episode

The episode explores the reasons behind traffic signals and road rules with expert Mike Knodler.

Why is there traffic? How do traffic lights work? How do they know when to turn red and green? Why does green mean go and red mean stop? Why are cars able to go faster than they are allowed to go with the speed limit? Why do we drive on the right side of the road in the United States? Why are some roads bigger than others? Answers to your traffic questions with Mike Knodler, professor and director of the Transportation Center at the University of Massachusetts. Download our learning guides: PDF | Google Slide | Transcript

People in this episode

Guest: Mike Knodler

Topics covered

• traffic lights
• road safety
• transportation
• traffic rules
• speed limits

Keywords

• traffic
• traffic lights
• green means go
• red means stop
• speed limit
• road rules
• transportation

Mentioned in this episode

Organizations: University of Massachusetts

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