What is the term for two circular curves with different radii that lie on the same side of a common tangent?

• A. Compound Curve
• B. Simple Curve
• C. Converging Curve
• D. Joint Curve

Answer: (A)

The term for two circular curves with different radii that lie on the same side of a common tangent is known as a compound curve. In surveying, a compound curve is formed when two arcs, each with a distinct radius, are connected smoothly by a common tangent, providing a continuous transition from one curve to another. This design is commonly used in roadway or railway alignment to facilitate gradual changes in direction while maintaining vehicle stability and comfort.

In contrast, a simple curve refers to a single arc of a circle and does not involve the connection of two different radii. Converging curves involve two arcs coming together but are typically considered in contexts where their directions are approaching each other rather than lying on the same side. Joint curve is not a standard term used in surveying for this configuration and can lead to confusion with other curve types. The correct identification of a compound curve is crucial in engineering projects to ensure the alignment and safety of transportation routes.