Road surface

A road surface (British English) or pavement (North American English) is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, hoggin, cobblestone and sett granite were extensively used, but these have mostly been replaced by asphalt or concrete laid on a compacted base course. Asphalt mixtures have been used in pavement construction since the beginning of the 20th century and are of two types: metalled (hard-surfaced) and unmetalled roads. Metalled roadways are made to sustain vehicular load and so are usually made on frequently used roads. Unmetalled roads, also known as gravel roads or dirt roads, are rough and can sustain less weight. Road surfaces are frequently marked to guide traffic. Today, permeable paving methods are beginning to be used for low-impact roadways and walkways to prevent flooding. Pavements are crucial to countries such as United States and Canada, which heavily depend on road transportation. Therefore, research projects such as Long-Term Pavement Performance have been launched to optimize the life cycle of different road surfaces. Pavement, in construction, is an outdoor floor or superficial surface covering. Paving materials include asphalt, concrete, stones such as flagstone, cobblestone, and setts, artificial stone, bricks, tiles, and sometimes wood. In landscape architecture, pavements are part of the hardscape and are used on sidewalks, road surfaces, patios, and courtyards, among others. The term pavement comes from Latin pavimentum, meaning a floor beaten or rammed down, through Old French pavement. The meaning of a beaten-down floor was obsolete before the word entered English. Pavement, in the form of beaten gravel, dates back before the emergence of anatomically modern humans. Pavement laid in patterns like mosaics were commonly used by the Romans. The bearing capacity and service...