Superelevation and its Relationship with the Velocity of Vehicles

The superelevation, also known as the banking or cant of a road, refers to the slope or inclination provided on the horizontal curve of a road. It allows vehicles to safely negotiate turns at higher speeds by counteracting the centrifugal force that tends to pull vehicles towards the outside of the curve. The superelevation is typically achieved by raising the outer edge of the pavement with respect to the inner edge.

Direct Proportionality with the Velocity of Vehicles

The superelevation is directly proportional to the velocity of vehicles, which means that as the velocity of vehicles increases, the superelevation also increases. This relationship can be explained by considering the forces acting on a vehicle as it travels along a curved path.

When a vehicle moves along a curve, it experiences a centrifugal force that pushes it towards the outside of the curve. This force increases with the square of the velocity of the vehicle. To counteract this force, the road is banked or sloped to provide an inward force that balances the centrifugal force. The superelevation angle is designed to achieve this balance.

As the velocity of vehicles increases, the centrifugal force acting on the vehicle also increases. To maintain a balance between the centrifugal force and the inward force provided by the superelevation, the superelevation angle needs to be increased. Therefore, the superelevation is directly proportional to the velocity of vehicles.

Alternative Options

The other options mentioned in the question are incorrect:

- Inversely proportional to the velocity of vehicles (Option B): This is incorrect because, as explained above, the superelevation is directly proportional to the velocity of vehicles.

- Directly proportional to the width of the pavement (Option C): This is incorrect because the width of the pavement does not directly affect the superelevation. The superelevation is primarily determined by the design speed and the radius of the curve.

- Inversely proportional to the width of the pavement (Option D): This is also incorrect because the width of the pavement does not have an inverse relationship with the superelevation.

In conclusion, the superelevation is directly proportional to the velocity of vehicles. As the velocity of vehicles increases, the superelevation needs to be increased to maintain a balance between the centrifugal force and the inward force provided by the superelevation.