Angle Subtended by Radius of Curve for Single Lane Road Calculator

Formula Used:

\[ \alpha_1 = \frac{180 \times s}{\pi \times R_{trans}} \]

Angle Subtended (α₁):

1. What is Angle Subtended by Radius of Curve for Single Lane Road?

Definition: This is the angle formed by the radius of curve where the length of the spiral (Ls) is less than the length of the curve (Lc).

Purpose: It helps in designing transition curves for single lane roads, ensuring smooth vehicle movement around curves.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \alpha_1 = \frac{180 \times s}{\pi \times R_{trans}} \]

Where:

\( \alpha_1 \) — Angle subtended by radius of curve (radians)
\( s \) — Shift (meters)
\( R_{trans} \) — Radius for transition curve (meters)
\( \pi \) — Mathematical constant pi (~3.14159)

Explanation: The formula calculates the angle formed at the center of the curve based on the shift distance and transition radius.

3. Importance of This Calculation

Details: Proper calculation ensures safe and comfortable transition curves in road design, preventing sudden changes in centrifugal force.

4. Using the Calculator

Tips: Enter the shift distance (s) and transition radius (R_trans). All values must be positive numbers. Results include a ±5% tolerance.

5. Frequently Asked Questions (FAQ)

Q1: What is shift in road design?
A: Shift is the distance by which the curve moves to accommodate the shape of transition curve.

Q2: Why is this calculation specific to single lane roads?
A: Single lane roads have different design requirements than multi-lane roads, particularly in curve transitions.

Q3: What's a typical value for transition curve radius?
A: This varies based on design speed and road type, but typically ranges from 100m to 300m for single lane roads.

Q4: How does this angle affect road design?
A: It determines how gradually the curve transitions, affecting driver comfort and safety.

Q5: Why the ±5% tolerance?
A: This accounts for practical construction variations while maintaining design integrity.