---
title: "Disadvantages of heavy camber"
subject: "Transportation Engineering I"
chapter: 3
key: "semester_6/transportation_engineering_i:camber-disadvantages"
source: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/camber-disadvantages
site: BCT Engineering
---

# Disadvantages of heavy camber

Transportation Engineering I · Chapter 3: Geometric Design of Highway

- Asked in: 2071 Bhadra
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/transportation_engineering_i/camber-disadvantages
- Whole chapter: https://www.bctengineer.com/md/semester_6/transportation_engineering_i/chapter-3

## Question

What are the disadvantages of heavy camber?

## Short answer

Heavy camber concentrates traffic at the crown causing uneven wear, causes discomfort and instability, creates fast scouring flow at edges, increases cost, complicates blending with superelevation, and makes maintenance harder. Camber should be just enough for drainage.

## Answer

Camber is the cross slope given to the carriageway so that rainwater drains to the sides. A *heavy* (too steep) camber is one steeper than the value recommended for the surface type (about 2.0 to 2.5% for bituminous surfaces in IRC/NRS 2070). Its disadvantages are:

1. **Traffic concentrates at the crown.** Drivers avoid the steep sides, so vehicles use the centre of the road. This causes uneven wear, early rutting and cracking along the centre, and makes passing and overtaking difficult.
2. **Discomfort and unsafe driving.** Vehicles tilt towards the edge, steering becomes tiring, and slow vehicles and two-wheelers feel unstable. Tall or heavily loaded trucks risk overturning or sliding towards the edge, especially on wet surfaces.
3. **Fast, scouring flow at the edges.** Water runs quickly across the steep surface and erodes the shoulder and the pavement edge.
4. **Higher cost.** More material is needed at the crown, the surface area is bigger, and more construction effort is needed to make a steep cross-section.
5. **Difficulty at curves and junctions.** A heavy camber is hard to blend with superelevation on curves and with side roads at junctions, and needs a longer run-off.
6. **Harder maintenance.** Steep side slopes make resurfacing and shoulder maintenance more difficult and raise the risk of edge breaking.

Hence camber is kept just enough to drain the surface. IRC recommends about 1.7 to 2.0% for cement concrete and high-type bituminous surfaces, 2.0 to 2.5% for thin bituminous surfaces, 2.5 to 3.0% for WBM and gravel roads, and 3.0 to 4.0% for earth roads.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is a heavy camber?
   A. A cross slope flatter than recommended
   B. A cross slope steeper than recommended for the surface type
   C. A longitudinal gradient steeper than 5%
   D. A camber provided only on earth roads
   Answer: B. Heavy camber means the cross slope is steeper than recommended (about 2.5% for bituminous surfaces). (Key point: Meaning of heavy camber)

2. Why does heavy camber cause uneven wear and early cracking along the centre?
   A. Water collects at the crown
   B. Drivers avoid the steep sides and concentrate on the centre
   C. Trucks are banned from the edges
   D. The crown is made of weaker material
   Answer: B. Vehicles keep to the centre where the surface is flatter, so the crown wears and ruts. (Key point: Traffic concentration)

3. What is a safety disadvantage of heavy camber?
   A. Higher visibility at night
   B. Tall or loaded trucks may overturn or slide towards the edge, especially when wet
   C. Vehicles brake sooner
   D. Reduced noise
   Answer: B. The steep cross slope tilts vehicles to the edge, making driving unstable and risky. (Key point: Safety effect)

4. What happens to water on a heavily cambered surface?
   A. It ponds at the crown
   B. It flows fast and scours the shoulder and pavement edge
   C. It drains more slowly
   D. It infiltrates the base evenly
   Answer: B. Steep slope gives fast flow that erodes the shoulder and pavement edge. (Key point: Drainage effect at edges)

## Related in Transportation Engineering I

- [Camber value and disadvantages of heavy camber](https://www.bctengineer.com/question.md?key=semester_6%2Ftransportation_engineering_i%3Acamber-selection-disadvantages) — Transportation Engineering I, chapter 3