The article evaluates different types of car headlights to see how they affect the visibility of reflective traffic signs at night. By comparing U.S. and European headlamp models, researchers found that using certain types of headlights can make traffic signs harder to see, which could impact safety on the road. The study looked at how much light from the headlights hits the signs from different distances and found that some headlamps make the signs less bright. This information can help determine which type of reflective material is best for different types of headlights and where signs should be placed for optimal visibility.