Countries with posted speed limit signs manufacture the signage in one of three shapes: square, rectangle or circle. Most countries employ a rectangular sign with high-contrast lettering and numbering, while others use a round sign with an outline of a red circle. In many cases, speed limit signs incorporate a red circle around the posted speed limit.
While almost every country has its own speed-limit sign design, there are a few elements that appear in most. These include high-contrast colors such as white, red or yellow, and the numerical speed limit, which is listed in either kilometers or miles per hour. Speed limit signs posted in European countries are similar, often featuring the speed limit encircled in red on a rectangular sign. In some cases, these speed limit signs have verbiage in multiple languages to accommodate international travelers. In other areas, speed limit information is painted on a road's surface.
Countries such as South Africa use a simple, circular sign with the speed limit posted in the center.
Many countries have a default speed limit at times and locations in which the speed limit is unknown. These default limits are enacted by a country's governing body and may vary depending on the type of road traversed.