Aluminum Road Stud Marker Rate. Solar Aluminum Road Stud Marker use stored solar energy to operate built-in light-emitting diodes (LEDs), providing effective guidance to drivers. At a speed of 900 miles per hour, when traveling at a speed of 60 miles per hour, the reaction time is extended from 3.2 seconds to more than 30 seconds.SolarAluminum Road Stud Marker are automatically activated from dusk to dawn, and they also integrate conventional mirrors to provide a road profile during the day.