Deviation Angle with Positive Grade Angle Calculator

Deviation Angle Formula:

\[ N = \frac{n1 \times (h2 - h1)}{\sqrt{h1 \times h2} - h1} \]

Deviation Angle: %

1. What is a Deviation Angle Calculator?

Definition: This calculator determines the deviation angle based on positive grade angle, driver sight height, and obstruction height.

Purpose: It helps in transportation engineering to calculate sight distance requirements on vertical curves.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ N = \frac{n1 \times (h2 - h1)}{\sqrt{h1 \times h2} - h1} \]

Where:

\( N \) — Deviation angle (%)
\( n1 \) — Positive grade angle (%)
\( h1 \) — Driver sight height (m)
\( h2 \) — Height of the obstruction (m)

Explanation: The formula calculates the angular deviation needed to maintain proper sight distance considering the vertical alignment and obstructions.

3. Importance of Deviation Angle Calculation

Details: Proper deviation angle calculation ensures safe stopping sight distance on roads with vertical curves, preventing accidents.

4. Using the Calculator

Tips: Enter the positive grade angle (%), driver sight height (default 0.75m), and obstruction height (default 0.36m). Heights must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical driver sight height?
A: The standard is 0.75m (75cm) representing the eye height of a passenger car driver.

Q2: What's a typical obstruction height?
A: 0.36m (36cm) is commonly used, representing the taillight height of vehicles.

Q3: Can this calculator handle negative grades?
A: The formula is designed for positive grades. For negative grades, different calculations may be needed.

Q4: What units should I use?
A: Use meters for heights and percentage for angles. The result is in percentage.

Q5: How precise should my inputs be?
A: Two decimal places are usually sufficient for most engineering applications.