One of the things you’re bound to notice while driving are lights. And there are so many kinds of lights that shine along streets and roads: the turn signal of the car in front, the neon display of a shop, and the glowing symbols on your dashboard. Like most things that have something to do with road and vehicle safety, these lights mean specific things

Here are the meanings behind the colors of different lights you can see along roads and streets.

Emergency Vehicle Lights

You’ve probably yielded to an ambulance or fire truck at least once. Or maybe you’ve just seen one drive past you. Emergency vehicles only flash their lights and sirens when on the way or responding to a crisis. But not all these transports use the standard red and blue lights. The color of a vehicle’s lights informs you what kind of responders they are.

The state laws of New York authorize the  light bars on police vehicles to be red and white. They can also use blue lights for contrast and visibility. Official emergency vehicles are the only ones that can use red and white flashing lights. These include ambulances, fire trucks, and blood delivery vehicles.

Cool colored flashing lights indicate volunteer emergency vehicles. Drivers of volunteer ambulances, sometimes used when official ambulances can’t access an area, can put a flashing green light on their vehicles. Volunteer fire fighters can attach a flashing blue light to their vehicles. In each instance, they can only turn on these lights when engaged in emergency services.

Arrangement of Traffic Lights

The meanings of the red, yellow, and green bulbs of a traffic light are among the most basic information every driver knows. The colors of these lights were adapted from railroad lines during the 19th century. In those days, a red light indicated that a train should slow down while a green one meant that they could maintain speed. The people who adopted it for street use added the yellow light.

Designers placed the red light on top of the others so that drivers can see it first. You can also see the red light immediately if you drive up the crest of a hill and above obstructions. This gives you time to slow down your vehicle before even getting too close.

But the arrangement does not apply in Tipperary Hill, New York. The predominantly Irish locals disliked the idea of red, symbolic of Britain, over the green of Ireland. Local youths vandalized the traffic light on an important intersection so many times that the local government installed one that placed the green light on top. If you ever drive by the area, you can see the traffic light proudly blinking Ireland’s color.

Street Lamps, Dim Glow

street lights

In the past few years, you might have noticed that many cities and towns changed their street lamps from orange to white LED bulbs. One of the reasons for this change is that the white lights greatly improve visibility and correct color recognition of vehicles. The latter is important during police chases or for identifying vehicles involved in hit-and-run incidents.

Unfortunately, the high intensity of the bulbs have negative side effects to people and the environment. The glare of the bulbs can cause insomnia among people living near them, and they can also confuse birds, insects, and animals. The strong illumination disrupts the sleep cycles of animals and people. Fortunately, LED bulbs of lower intensity are now replacing these lamps, providing a softer glow with fewer disruptions.

Writers have used light as a metaphor for education. It’s the basis for the word “enlightenment,” after all. It’s only fitting, then, that the lights you can see flashing past you in the street give off not only illumination, but also information.