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Red Light, Green Light: The Science Behind Traffic Signal Systems

Horia Varlan
/
Creative Commons

Here's a riddle for you: What's green and yellow, but most often red?

...Give up? It's a traffic light -- you know, those things you hit on your way into the office each morning. 

But how do they work? And why don't they ever seem to be synched up? 

This hour, we explore the science behind traffic light programming. We hear from engineers and experts in Connecticut and Utah. We also find out how new "smart" signals are improving traffic flow in Pittsburgh, Pennsylvania. 

And later, if you've ever gotten turned around while driving through downtown New Haven, you’re not alone. We learn how converting from a one- to two-way street system could make the city safer and easier to navigate.

GUESTS:

  • Jack Carey - Associate at Fuss & O’Neill, an engineering consulting firm in Manchester, Connecticut
  • Lisa Miller - Traveler Information Manager at Utah Department of Transportation
  • Stephen Smith - Research Professor in Robotics at Carnegie Mellon University
  • Doug Hausladen - Director of Transportation in New Haven; Acting Executive Director of the New Haven Parking Authority

Join the conversation on Facebook and Twitter.

John Dankosky and Chion Wolf contributed to this show.

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SOMOS CONNECTICUT es una iniciativa de Connecticut Public, la emisora local de NPR y PBS del estado, que busca elevar nuestras historias latinas y expandir programación que alza y informa nuestras comunidades latinas locales. Visita CTPublic.org/latino para más reportajes y recursos. Para noticias, suscríbase a nuestro boletín informativo en ctpublic.org/newsletters.

Fund the Facts

You just read trusted, local journalism that’s free for everyone, thanks to donors like you.

If that matters to you, now is the time to give. Join the 50,000+ members powering honest reporting and a more connected — and civil! — Connecticut.

Connecticut Public’s journalism is made possible, in part by funding from Jeffrey Hoffman and Robert Jaeger.