One of the most notable flaws of highways, and that includes the most dangerous highways in the U.S., is that they’re not fully illuminated. You might encounter a few street lights on a certain highway exit, near a tollbooth, or perhaps when crossing a border, but otherwise, most of the highway remains dark when you’re driving at night. Some people have turned to night driving glasses to try and drive safer in the dark, but there are safety measures installed on the roads themselves for this. Chances are, if you’ve done a lot of highway driving after sunset, you’ve seen those orange reflective poles on the side of the road, and you’ve probably wondered what they are.

They go under several different names, but the most common ones are “road reflectors” or “delineators.” As these names imply, they reflect your headlights, allowing you to see where the side of the road is. This generally improves your visibility in spots where there is no lighting, especially in bad weather. They might look different from highway to highway, but they all serve that specific purpose. Road reflectors are primarily intended for safety, and there are a few different types that you might encounter.

Most highways or freeways around the world commonly place these posts on either sides of the road, usually behind the guardrail if there is one. They also tend to look different from place to place. Sometimes the posts themselves are white, while the reflective material sits inside a black border. The most common form is a white post, with a little piece of orange reflective material adhered directly on the front, facing oncoming traffic.

There are various different types of reflective materials used on these posts, and they work much like most regular road signs. Basically, they reflect the beam of the headlights back to the driver, to make them more visible without relying on independent illumination.

The most obvious benefit to having road reflectors is safety. With these objects, drivers can much more easily make out the shape of the road, so they can adjust their steering and throttle accordingly. It also increases visibility a great deal when there’s a lot of rain or fog. This is a helpful solution to lack of highway illumination at night. Because while it would be great for highways to have light posts for hundreds of miles, the cost of implementing them and the resulting electricity costs are ultimately not feasible.