Have you ever noticed that the light bulbs that light up your neighborhood streets and traffic signals last a really long time? So what gives; how do they last so long, while the bulbs in your house don't? Here's a crash course for you.
Most of the bulbs used in the tall street lights are HID bulbs. This, incidentally, means absolutely nothing to most people! =) Here's why it matters: HID bulbs don't have the stuff in them that makes a normal light bulb burn out (filaments). The way they make light is totally different. They also use a lot less energy than normal street lighting, which makes a lot of sense for the city managers.
The traffic signal light bulbs are mostly LED these days, but there are still some stoplight bulbs that are the old fashioned style. They're made specially by the lighting manufacturers to last a really long time, but they still use a lot of energy and are sure to be eventually fully replaced with newer technology. They have odd wattages, like 118 watts or 196 watts, but they have the same shape and screw-in base as any normal light bulb has. Oddly enough, the traffic lights that are brightest when driving, at least to my eye, are the lower wattage LED lights--I can see those brightly from miles away. Now, if I could just find a remote that would make them green in my direction.... =)