What Those Little Scoops On Top Of Traffic Lights Are For

Unless you live in a climate where snow is a regular occurrence during the winter months, chances are you have no idea what those scoopy-looking things atop traffic lights are. The fact is, stoplights have gone through a long and strange evolution, first appearing in London, England, in 1868 (some 20 years before cars were even a thing). Today's modern traffic control systems are infinitely more complex than you probably realize. 

From odd-shaped "bells" to black boxes and white squares, there is now an assortment of gadgets attached to or located near virtually every traffic signal that we either never notice or don't have the foggiest notion about what they do. Most signal units now come with fully enclosed hoods that really help make them more visible to drivers, but that wasn't always the case. Those now-standard hoods (aka visors) do a great job at blocking the sun's glare, much the same way a baseball cap shields the sun from a person's eyes.

They work perfectly fine in areas where snow isn't a concern, but do the exact opposite when Old Man Winter acts up, turning them into snow catchers that ultimately block them from the driver's view. Enter the snow scoop visor, which features two rather simple tweaks to the otherwise normal visor. One version (made by SWARCO McCain, Inc.) features a louvered vent at the top of the hood and a portion of the bottom removed, which work in tandem to increase the vertical movement of air across the lens face and help keep snow from building up inside the hood.

Very early traffic lights were illuminated by flames fed by natural gas. As technology advanced, so too did the way they were brought to life. When electricity became prevalent, incandescent bulbs filled with a nitrogen-argon mixture became the go-to lighting method. These inert gases prevented the tungsten filaments from evaporating and helped keep the inside of the bulbs from becoming blackened. Incandescent bulbs were very hot, which was great for melting snow, but had relatively short lifespans and thus needed to be replaced fairly often.

Halogen bulbs eventually replaced the old incandescent ones, but far more energy-efficient LEDs are all the rage today. There is one problem, though: these light-emitting diodes don't give off nearly enough heat to melt snow, so a new method was needed to rid the nasty-to-drive-in white stuff. As such, the scoop tunnel visor was devised as a simple yet effective way to prevent stoplights from becoming obscured. Typically made from powder-coated aluminum to resist corrosion over time, they're unfazed by harsh climates and don't require any electricity. Equally important, maintenance crews don't need to go around and remove built-up snow from inside every single visor, all of which saves both time and money.

But it's not the only method used to beat back Old Man Winter's wily ways. Manufactured by Snow Proof Signals LLC, snow cones are exactly what they sound like — a clear, shatter-resistant, cone-shaped piece of UV-resistant polymethyl methacrylate acrylic thermoplastic placed directly over the light. Adapted from New York's Department of Transportation, it too sits passively (inside a standard hood) and, like the louvered snow-scoop visor, prevents snow from building up.