- 2078 Baisakh · 4 marks
Camber and its types
Short answer
Camber is the transverse slope on straight roads for drainage. Types include parabolic (best for high-speed bituminous/concrete), elliptical (higher speeds), straight-line (simple, low-cost), composite (parabolic center with straight edges), and one-way (single slope for curves/hill roads). Recommended values range from 1.7-2% for concrete to 3-4% for earth roads.
Discuss camber with its types.
Camber (cross fall) is the convexity or transverse slope given to the carriageway surface of a straight road, with the centre higher than the edges, to drain rainwater to the side drains.
Types of camber
- Parabolic camber: the cross profile is a parabola, steeper near the edges and flat at the centre. The best for fast traffic; used for bituminous and concrete roads. Equation ( measured from the centre line, = average cross slope, = width).
- Elliptical camber: an elliptical profile; used for roads with higher speeds.
- Straight line (sloped) camber: two straight slopes meeting at the crown; simple to construct; used for low-cost roads and with moderate speeds. A rounded crown is provided.
- Composite camber: a parabola near the centre and straight lines near the edges; combination for better appearance and drainage.
- One-way camber (single slope): the whole carriageway slopes to one side; used on curves (with superelevation), hill roads and one-way roads.
parabolic straight composite
_.-"-._ __/\__ _.-"-._
Recommended values (IRC; check NRS 2070)
| Surface | Camber |
|---|---|
| Cement concrete, high bituminous | 1.7-2.0% |
| Thin bituminous | 2.0-2.5% |
| WBM / gravel | 2.5-3.0% |
| Earth road | 3.0-4.0% |
Higher camber is for heavier rain and rougher surface.
✓ Answer checked by Claude Opus 5.5 (high effort)