The new ones are much clearer at night. It's hard to describe (or to photograph), but the reflective properties are much better.
Of course they are clearer, they are new. The reflective coating has worn off of the old ones.
Road signs are reflective thanks to the glass beads, microprisms, or encapsulated lenses present on reflective sheeting. These materials bend light, so it comes back to the source, making road signs highly visible at night to drivers with their headlights on. There are three different grades of this sheeting: engineer, high-intensity, and diamond.
Engineer Grade Reflective Signs
Engineer grade signs use glass beads or prismatic optical technology to reflect light and have the lowest prices. Engineer grade signs have less visibility, usually around 400 to 600 feet, making them only suitable for non-critical uses. You will often see these signs in areas like parking lots and garages.
High-Intensity Grade Reflective Signs
High-intensity signs use cube-corner or prismatic material to offer superior reflectivity. Most cities use these for their traffic signs. You will also see high-intensity grade reflective signs used for barricades and construction zones. They provide better visibility than engineer grade signs and can be seen from around 800 to 1,200 feet away. They work well in areas where street lights can affect reflectivity.
Diamond Grade Reflective Signs
Diamond grade signs have the highest visibility, around 1,300 to 1,600 feet. They are used in areas where high visibility is critical, including interstate highways. These are the best option for cluttered urban environments that have a lot of lights and other signs.