03. Highway Planning and highway components.pptx

Highway Planning and highway components.

1. Highway Planning Planning is considered as a prerequisite before attempting any development program, particularly when the funds are limited and total requirements are much higher. Highway planning is also a basic need for highway development. 1 Dr. Rizwan Memon

2. The objects of highway Planning are: To plan a road net work for efficient and safe traffic operation, but at minimum cost. To arrive at the road system having maximum utility which could be constructed within the available resources during the plan period. To fix the priorities for development of each road link based on the utility as the main criteria for phasing the road development. 2 Dr. Rizwan Memon

3. To plan for future requirement and improvements of roads in view of anticipated developments To work out financing systems Highway planning phase includes: Assessment of road length requirement for an area. Preparation of Master Plan showing the phasing of plan in annual or five year plans. 3 Dr. Rizwan Memon

4. The planning surveys includes following studies: Economic Studies Finacial Stuides Traffic or road use studies Engineering Studies Planning Surveys 4 Dr. Rizwan Memon

5. Economic Studies includes: Population and its distribution in each village, town or other locality Trend of population growth Agricultural and Industrial products and their listing in classified groups area wise. Industrial and Agricultural development and future trends Existing facilities with regards to communication, recreation and income. Per capita income 5 Dr. Rizwan Memon

6. Financial Studies includes: Sources of income and estimated revenue from road transport Living Standards Resource from local levels, toll taxes, vehicle registration and fines Future trends in financial aspects 6 Dr. Rizwan Memon

7. Traffic and Road use Studies includes: Traffic volume in Vehicles/day, Annual Average Daily Traffic (AADT) and Peak Hourly Volume (PHV) Origin and Destination Studies (O & D Studies) Traffic Flow Patterns Accidents, their cost analysis and causes Future trend and growth in traffic volume and goods traffic Growth of passenger trips and the trend in the choice of modes 7 Dr. Rizwan Memon

8. Engineering Studies includes: Topographic Surveys Soil Surveys Location and Classification of existing roads Estimation of possible developments in all aspects due to proposed highway development Special problems in drainage, construction and maintenance of roads 8 Dr. Rizwan Memon

9. The various details collected from the planning survey should be presented in the form of PLANS The Master Plan should be prepared, which is the final road development plan for the area under study. The next step is to compare the various alternates proposed of road systems in hand and to select the one which may be considered as best under plan period. 9 Dr. Rizwan Memon

10. Components of Highway Geometric Design Cross-section Elements Carriageway: the portion of the roadway provided for the movement of vehicles, exclusive of shoulders Roadway: the portion of a highway including shoulders for vehicular use Median: the physical or painted separation provided on divided highways between two adjacent roadways. Camber: Convexity provided to the surface of carriageway, known as crown. Bicycle and pedestrian facilities Utility areas Drainage channels and side slopes 10 Dr. Rizwan Memon

11. Example – two lane rural highway cross-section design features and terms Source: Flexibility in highway design, FHWA 11 Dr. Rizwan Memon

12. Components of Highway Geometric Design Sight Distances Consideration Length of the roadway ahead visible to drivers, must allow driver to perceive, reaction, stop, change speed, and change direction etc. when necessary Stopping Sight Distance (SSD) Overtaking Sight Distance (OSD) Intersection Sight Distance (ISD) 12 Dr. Rizwan Memon

13. Components of Highway Geometric Design Horizontal Alignment Horizontal Curves The change in road direction be made possible by introducing horizontal curves Superelevation Raising of outer edge to counteract the centrifugal force Extra widening of Pavement To introduce the centrifugal force and superelevaion Transition Curve Gradual change between the straight and Circular Curve 13 Dr. Rizwan Memon

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15. Components of Highway Geometric Design Vertical Alignment Gradient Rate of rise or fall of road level along its ength Vertical Curves The change in gradient be made possible by introducing vertical curves Summit Curves Valley Curve 15 Dr. Rizwan Memon

16. Components of Highway Geometric Design Intersection Elements Design of road intersections with facilities for safe and efficient movement of traffic. At-Grade Intersection Grade -Separated Intersection 16 Dr. Rizwan Memon