What is thenormal size of the letters on an traffic sign?

The normal size of letters on traffic signs varies depending on the type of sign and its intended visibility distance. For instance, regulatory signs typically use letters that are at least 6 inches tall for visibility from 200 feet away, while larger guide signs may use letters that are 12 inches tall or more for visibility from greater distances. Specific guidelines, such as those from the Manual on Uniform Traffic Control Devices (MUTCD) in the U.S., provide standardized dimensions for different sign types to ensure consistency and safety on the roads.