Contact theSOPAbout theSOPSupport theSOPWritersEditorsManaging Editors
theSOP logo
Published:September 15th, 2005 12:26 EST

Traffic Lights Become More Energy Efficient in Carbondale, Illinois

By Matthew Kent

The city of Carbondale expects to save $37, 500 a year after replacing the traffic signals at 25 intersections with energy-efficient LED lights.
LEDs, or light-emitting diodes, are tiny electronic lights that use up to 85 percent less energy than traditional incandescent light bulbs.  According to, most of the light produced with a traditional bulb involves generating heat, which is wasted energy.  LED lights produce little heat, so more energy is concentrated in producing light.

Carbondale's LEDs were largely funded by an $86,970 grant from the Illinois Clean Energy Community Foundation. City Manager Jeff Doherty said the city also paid $16,293 and the Illinois Department of Transportation contributed $20,321 to the upgrades.

Because they are about the size of a pencil eraser, hundreds of LEDs are grouped together in a traffic light.  Additionally, LED lights do not have filaments like traditional incandescent bulbs, so they last for years versus months, reducing operating and maintenance expenses.  With the ability to run on batteries during power outages, LED lights also enhance safety through better light quality and improved reliability.

"At each intersection, the city would save $1,500, which is pretty significant," said Christine Marichioror, legislative associate of the Illinois Municipal League, an organization that connects cities across the state with legislative and community resources.

While experts say the benefits of LEDs are plentiful, cost has proved to be a barrier.  But the cost of the 20-year-old technology has decreased over the past decade, and organizations such as Illinois Clean Energy Community Foundation help cities with the initial cost.

Last year, the foundation awarded $3.8 million in grants across the state.  Bob Romo, a program officer for the foundation, said the group provides 80 percent of costs to do the LED upgrade.
"Traffic engineers like the bulbs because they're reliable and their concerns are alleviated," Romo said.

In awarding funding, he said the foundation determines awards based on need.  Quincy, Springfield, and Edwardsville were also awarded grants last year.  "We choose the most cost-effective project," Romo said.  "LEDs are more expensive; the cost has been the barrier."