New instrument that measures LED intensity could help cities with traffic light maintenance

September 24, 2012

(Phys.org)—In many of the nation's traffic lights, light-emitting diodes or LEDs with their brighter light and longer life have replaced standard bulbs. But knowing when to replace the signal heads has remained a guessing game, says Dr. Suzanna Long, assistant professor of engineering management and systems engineering at Missouri University of Science and Technology. That's because LED traffic lights don't burn out - they just lose brightness over time.

So Long and other researchers at Missouri S&T, in partnership with the Missouri Department of Transportation, have developed an instrument to measure intensity. The laser-guided device allows measurements to be taken from the roadside at night, instead of requiring technicians to physically check by using a bucket truck.

Long's team created the measurement tool while working to provide MoDOT with a data-driven replacement schedule for LEDs, which have been widely adopted for use in sustainable traffic signal management.

"The majority of agencies replace LED signals on a spot basis when they receive a complaint," she says. "The maintenance costs associated with sending a crew out to replace a single LED are very high. Our methodology provides a more cost-effective mechanism for determining replacement and allows agencies to meet goals of being good stewards of public money."

Long says in addition to addressing individual complaints about brightness, transportation officials have used a generic replacement schedule based on the manufacturers' warranties, usually six years. But since life expectancy of LEDs varies by intersection and the basic science of LED components, that's not the most cost-effective schedule.

Results of this study, named one of the 2012 "Sweet 16" High Value Research Projects by the American Association of State Highway and Transportation Officials, appears in the Engineering Management Journal's special issue on transportation management this month.

The team plans to extend the previous data and collect data from the same LED traffic indicators in the coming years to improve the reliability and accuracy of their results.

Explore further: LED there be light

Related Stories

LED there be light

June 22, 2009

Q: How many LED engineers does it take to change a light bulb?

Researchers create a smaller, flexible LED

June 20, 2011

University of Miami professor at the College of Engineering, Jizhou Song, has helped design an light-emitting diode (LED) light that uses an array of LEDs 100 times smaller than conventional LEDs. The new device has flexibility, ...

Cell phone signals help manage traffic

September 26, 2011

In a pilot project in Texas, Siemens is developing intelligent transportation technology for the fast and orderly evacuation of citizens. In this project, traffic light timing systems register traffic flow and adjust the ...

Taiwan saves electricity with new traffic lights

September 28, 2011

Authorities in Taiwan said Wednesday they had changed more than 690,000 traffic lights throught the island in a project that will save enough electricity to power more than 60,000 homes.

Recommended for you

Software turns smartphones into tools for medical research

July 27, 2015

Jody Kearns doesn't like to spend time obsessing about her Parkinson's disease. The 56-year-old dietitian from Syracuse, New York, had to give up bicycling because the disorder affected her balance. But she still works, drives ...

Where is solar power headed?

July 22, 2015

Most experts agree that to have a shot at curbing the worst impacts of climate change, we need to extricate our society from fossil fuels and ramp up our use of renewable energy.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Tomwilliam
not rated yet Sep 25, 2012
LED Light technology is going to revolutionize lighting technology.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.