Traffic lights go out when we lose power, causing gridlock that interferes with emergencies and evacuations. What could we do to avoid this? Granger Morgan, professor at Carnegie Mellon University, Co-Director of the Center for Climate and Energy Decision Making and Co-Director of the Electricity Industry Center, explains how we might retain power in this episode of Energy Bite.

Listen

Respond

More Information

How Stuff Works: Why are they replacing all of the traffic lights in my town?

Traffic Sunlights

California Department of Transportation/Traffic Signals and Lighting 

Wind-powered traffic lights to get tested

Solar in Action (Boston)

Boston Solar Evacuation Route

Episode Transcript

HOST INTRO: If the power goes out in a city, traffic lights stop working and traffic quickly snarls. Is there any way to avoid that?

On this week’s Energy Bite, Granger Morgan, a Professor at Carnegie Mellon University, has some answers.

DR. GRANGER MORGAN: Snarled traffic can be a serious problem in a blackout, especially if police, fire and ambulances can’t get through. But, there is any easy way to avoid the problem – use traffic lights that have battery back up.

HOST: How does this work? Don’t traffic lights use a lot of power?

DR. GRANGER MORGAN: The older style of traffic lights that used incandescent light bulbs certainly did. But today traffic lights are being switched to solid state LEDs. Those are the ones that look like they are made up of many small dots.

Because LED lights are very efficient, they can run on a battery. If a small solar panel is added at each intersection, the traffic lights can be completely independent of the power grid.

HOST: Wouldn’t that be expensive?

DR. GRANGER MORGAN: Because running an LED light costs only 10% as much as conventional lights, many communities are already converting their traffic signals and saving money. At busy intersections, adding independent battery back-up power can be a very prudent investment.

HOST: Would you be willing to support the cost of installing solar traffic lights in your town? Take our poll, see the results, and ask your energy questions at Energy Bite dot org.

Energy Bite is a co-production between 90.5 WESA and Carnegie Mellon’s’ Scott Institute for Energy Innovation.