1. What is the Omni Vertical Curve Equation?

The Omni Vertical Curve equation calculates the minimum length of a vertical curve required for safe sight distance in road design. It ensures drivers have adequate visibility when transitioning between different grades.

2. How Does the Calculator Work?

The calculator uses the Omni Vertical Curve equation:

Where:

• \( L \) — Vertical curve length (feet)
• \( A \) — Algebraic grade difference (%)
• \( S \) — Sight distance (feet)
• \( H \) — Height difference (feet)

Explanation: The equation balances the grade change with required sight distance and height considerations for safe vehicle operation.

3. Importance of Vertical Curve Calculation

Details: Proper vertical curve design prevents abrupt grade changes that could cause vehicle instability, improve drainage, and ensure adequate stopping sight distance.

4. Using the Calculator

Tips: Enter the algebraic difference between grades (A) in percentage, sight distance (S) in feet, and height difference (H) in feet. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is algebraic grade difference (A)?
A: It's the absolute value of the difference between the incoming and outgoing grades (in percent).

Q2: How is sight distance (S) determined?
A: Sight distance is typically based on design speed and includes both stopping distance and decision distance.

Q3: What does height difference (H) represent?
A: It's the vertical offset between the driver's eye height and the object height (typically 3.5 ft for driver's eye and 2 ft for object).

Q4: When is this equation most applicable?
A: For crest vertical curves where sight distance is limited by the curve itself rather than roadway features.

Q5: Are there limitations to this equation?
A: This is a simplified model. More complex calculations may be needed for precise engineering designs.