Three years ago, Cambridge, Mass., made a smart move.

That's when the city started swapping the incandescent bulbs on its 136 traffic lights with LEDs, slashing its electricity bill because the LEDs draw 25% less power. They also last three to five times longer and burn brighter. And as demand increases and technology advances, prices have dropped.

The only problem is one that traffic engineer Jeff Parenti and his team couldn't have foreseen: The low-energy lights emit no heat. The trait usually isn't a problem. But when winter storms drive snow sideways, it accumulates on lamp visors, obscuring the lenses so motorists and pedestrians can't see the traffic light's color.

"We don't have many snow storms like that, so it's way down on my list of things to worry about," says Parenti.

That would be that, except that Cambridge is home to Tom and Ray Magliozzi (also known as Click and Clack, the Tappet Brothers), hosts of the nationally syndicated radio show, "Car Talk." Each week they present a "puzzler," or a particularly irksome problem. The listener who solves the puzzler scores a $26 gift certificate, or some other fabulous prize, to the "Shameless Commerce Division" of the show's Web site. www.cartalk.com

It so happens that the Oct. 15 puzzler involved Cambridge's new traffic lights. A producer called Parenti, who verified that the old incandescent lights melted snow better than the LED lights. The puzzler gave Parenti 15 seconds of fame when Ray Magliozzi told the national audience about chatting with "the chief traffic guru in our fair city."

Ah, the law of unintended consequences. Vendors tout products and processes to help you and your team "do more with less." It's only after the purchase order's been signed and the new technology is out in the field that unforeseen challenges rear their heads. If you're lucky, as is the case with LED traffic lights, the difficulty isn't debilitating. But it can require some ingenuity to resolve.

What unexpected experiences have you had with a new product or process? And what would you caution your colleagues to consider before investing in a similar technology? Let me know at sjohnston@hanleywood.com. We can't give you a gift certificate, but we can provide you 15 minutes of fame when we relate your helpful hints in the magazine or online.

Stephanie Johnston
Editor in Chief