Point of Tangency:

The point of tangency is the point on a fore tangent where the alignment changes from a curve to a straight line. It marks the transition point between the curved section and the straight section of the road or railway alignment.

Importance of Point of Tangency:

- The point of tangency is crucial in road or railway design as it determines the smooth transition between the curved and straight sections of the alignment.
- It ensures that vehicles or trains can travel along the alignment without any sudden changes in direction, which could lead to safety hazards or discomfort for passengers.

Design Considerations:

- Engineers carefully design the point of tangency to ensure that the transition is gradual and safe for users.
- Factors such as design speed, sight distance, and vehicle characteristics are taken into account when determining the location of the point of tangency.

Construction and Maintenance:

- During construction, the point of tangency is marked and constructed according to the design specifications to ensure the alignment meets the intended geometry.
- Regular maintenance is required to ensure that the point of tangency remains in good condition and continues to provide a smooth transition between the curved and straight sections of the alignment.

In conclusion, the point of tangency plays a crucial role in road and railway design by ensuring a smooth transition between curved and straight sections of the alignment. Engineers carefully consider various factors when designing the point of tangency to provide a safe and comfortable experience for users. Regular maintenance is essential to preserve the integrity of the point of tangency and the overall alignment.