HRE

• Foot paths are the oldest mode of travel.
• Animals were also used to transport people and goods
• The first road on which there is an authentic record is that of the Assyrian Empire,about 1900 B.C.
• Such a hard surface is believed to have existed in Mesopotamia in the period about 3500 B.C.
• Roman roads are the best preserved construction technique in the world and are still used today.
• Romans are considered to be pioneers in road construction.
• The main feature of Pierre Tresaguet's proposal was that the thickness of road construction needed is 30 cm
• Pierre Tresaguet was the Inspector Generakk of Roads in France from 1775 to 1785
• John Metcalf (1717-1810) was engaged in road construction works in England.
• Thomas Telford was the founder of the Institution of Civil Engineers at London.
• John Macadam was the Surveyor General of Roads in England, and his new concept of road construction became known bythe year 1827.
• Macadam recognized the importance of subgrade drainage and compaction, and so the roads were built with a cross slope of 1 in 36.
• Macadam was the first person who suggested that heavy foundation stones are not at all required to be placed at the bottom layer, realizing that the subgrade being the lowest portion of the pavement should be prepared properly.
• Water Bound Macadam is the layer of broken stone aggregates bound together by stone dust or screening material and water applied during construction and compacted by heavy smoothed wheel roller.
• Water Bound Macadam can't last under under adverse weather conditions. Therefore, further developments in road construction use bituminous materials and concrete
• Classification of roads based on the type of road pavement; paved roads, and unpaved roads.
• Classification of roads based on their use; National Primary roads, National Secondary roads, National Tertiary roads, Provincial roads, Municipal roads, Barangay roads, Expressways, and Bypasses.
• Roads that are negotiable during all weather, except at major river crossing are called All-weather roads.
• Fair weather roads are roads wherein traffic may be interrupted during monsoon season at causeways where streams may overflow across the road.
• Surface roads are roads provided with bituminous surfacing and are also called black topped roads.
• Unsurfaced roads are not provided with bituminous or cement concrete surfacing.
• This type of road pattern is a hexagonal pattern.

  
• radial or star and grid pattern

  
• radial or star and circular pattern

  
• rectangular or block pattern

  
• radial or star and block pattern

  
• Highway planning includes the assessment for the length requirement for an area.
• The position or the layout of the center line of the highway on the ground is called the alignment.
• Financial studies are essential to study the various financial aspects like sources of income and the manner in which the funds for the project may be mobilized.
• Traffic studies include all the details of the existing traffic, their volume, and pattern of flow should be known before any improvementcould be planned
• The studies that collect the various details that are useful in estimating the economics involved in the highway development program, hence its desirable to find the service given by each road system to the population and products of the area is called economic studies.
• All details of topography, soil and other problems such as drainage, construction and maintenance problems should be investigated before a plan/program is suggested is under engineering studies.