Subway lines or light rail corridors in large urban centers Harbors and ports to import/export Waterways and Ferry terminals for inland transport Pipelines to transport petroleum, gas and waterHowever, this course shall be limited to roads and affiliate infrastructure planning, design, construction and management.1.3The RoadThe road is defined as a long and wide strip of land joining two places, that has been paved or improved surface to allow vehicles move smoothly on top.Brief historyLong ago: The earliest stone paved roads have been traced to about 4,000 B.C. in the Indian subcontinent and Mesopotamia (current Iraq). Romans: Later in history, to support the movement of military caravans throughout the empire, the Romans developed techniques to build durable roads using multiple layers of materials at the top of deep beds of crushed stone.McAdam Road: Modern road-construction techniques can be traced to a process developed by Scottish engineer John McAdam in the early 19th century. Topped multi-layer roadbeds with a compacted soil and crushed stone aggregate mix that was then packed down with heavy rollers to lock it all together. Contemporary asphalt roads are improved form of McAdams' methods with
modern alterations.Types (Classifications) of Roads Classification of roads is based on many factors such as materials, locations, function, traffic volume, width, economy, traffic type, rigidity and topography. Brief details of each class is described below:Types of Roads Based on MaterialsEarthen RoadsThese are laid with soil in less traffic areas and are the cheapest of all types. Gravel RoadsThese are also low quality roads and are formed by compacted mix of gravel and earth. Murrum roadsMurrum (red soils) are used to make Murrum roadsWBM roadsWater Bound Macadam (WBM) roads are rough roads contain crushed stone its base course with an aggregate spread on top. Bituminous roadsThese are the most used roads, with flexible top, low cost and good driving conditions. Concrete roadsThese are composed of cement concrete with rigid top, higher cost and good performance under heavy loads.Types of Roads Based on Location and FunctionNationalHighwaysThese are main roads of a country connecting all major cities to the capital of the country. Minimum two lane road is provided for national highways.State HighwaysState (Provincial) highways are second main roads which connect major parts of state with in it. These highway ultimately connects to the national highways.District RoadsDistrict roads are provided with in the cities and connects markets and production places to provincial and national highways. These might be major or minor district roads.Rural Roads orVillage RoadsVillage roads connects the nearby villages with each other and lead to nearby town or district roads.