Introduction to Highway Cross-Sectional Elements .pptx

Highway Cross Sectional Elements

1. Highway cross-sectional elements By Pinki Deb

2. Highway cross sectional elements Under cross sectional elements, the consideration for the width of pavement, formation and land, the surface characteristics and cross slope of pavement are included The cross sectional elements are one of the important element of geometric design

3. The cross-sectional elements are as follows Cross-slope or Camber Width of pavement or carriageway Medians or traffic separators Kerbs Road Margins

4. Cross slope or Camber It is the slope provided to the road surface in the transverse direction to drain off the rain water from the road surface The objectives are To drain off the water from the surface To prevent entry of water into pavement layers Quick drying of pavement

5. Types of Camber

6. Width of pavement or carriage way Width of pavement or carriage way depends on Width of traffic lane No of lane The width of traffic lane depends on the width of vehicle and the clearance

7. Width of carriageway recommended by IRC Class of road Width of carriageway (m) Single lane road 3.75 Two lane, without raised kerbs 7.0 Two lane, with raised kerbs 7.5 Intermediate carriageway 5.5 Multi-lane pavement 3.5 per lane

8. Median Median is provided between two sets of traffic lanes intended to divide the traffic moving in opposite direction Functions of median are To channelize traffic into streams at intersection To shadow the crossing or turning traffic To segregate slow traffic To protect pedestrians

9. Kerbs Kerb indicate the boundary between the pavement and median or footpath. The types of Kerb Low kerb or mountable type kerb (height above 100 mm) Semi barrier type kerb (height above 150 mm) Barrier type kerb (height above 200 mm)

10. Shoulder Shoulders are provided along the road edge and is intended for accommodation of stopped vehicles, serves as an emergency lane for vehicles, provides lateral support to base and surface course. The minimum shoulder width as per IRC is 2.5 m

11. Guard Rails Guard rails are provided at the edge of the shoulder to prevent the vehicles from running off the embankment.

12. Footpaths Footpaths are the exclusive right of way to pedestrians specially in unban roads

13. Drive ways Drive ways connect the highway with commercial establishment like fuel station, service stations etc.

14. Cycle track It is provided in urban areas where the cycle traffic is high

15. Bus bays Bus bays may be provided by recessing the kerb to avoid conflict with moving traffic

16. Parking lanes Parking lanes are provided in urban areas for side parking

17. Service road or Frontage road Service roads may run parallel to the highway and are isolated by a separator

18. Thank You