(Photo courtesy of Arizona Department of Transportation)

When engineers at ADOT heard an LED bulb can save taxpayers 70 percent in energy costs over the Halogen bulb, they set out to replace the lights in more than 230 message boards across Arizona.

Those clever message boards hanging off highway overpasses throughout the state cost millions of dollars to replace, according to the Arizona Department of Transportation.  

So when engineers at ADOT heard an LED bulb can save taxpayers 70 percent in energy costs over the Halogen bulb, they set out to replace the lights in more than 230 message boards across the state.

But ADOT spokesman Peter Corbett said that became complicated.

“The company that originally supplied the 20-year-old signs went out of business,” he said.

Antiquated cranks and metal levers were no longer available to replace the existing bulbs, which meant they’d have to replace the boards entirely, which can cost more than $300,000 each.

Not to be defeated, “Our staff and engineers came up with a plan to do these retrofits for about $42,000 per sign. So, close to $260,000 savings per sign," said Corbett.

Using those same figures, the savings for replacing the more than 230 message boards statewide could reach well over $60 million.

Corbett said that’s not including the savings on reduced maintenance and safety costs spent to shut down highways to replace the original lights, which burned out three times faster than the new technology.

That savings, he predicted, will go toward road improvement projects across Arizona.