Velocity given Length Calculator by Tons of Concrete

Velocity given Length Calculator

Vehicle Velocity Formula:

\[ V = \sqrt{\frac{L_c \times 100 \times f}{g_1 - g_2}} \]

Length of Curve:

Allowable Centrifugal Acceleration:

m/s²

Upgrade:

Downgrade:

Vehicle Velocity (km/h):

1. What is a Velocity given Length Calculator?

Definition: This calculator estimates the vehicle velocity based on curve length, centrifugal acceleration, and grade changes.

Purpose: It helps transportation engineers determine safe vehicle speeds for given vertical curve parameters.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ V = \sqrt{\frac{L_c \times 100 \times f}{g_1 - g_2}} \]

Where:

\( V \) — Vehicle velocity (km/h)
\( L_c \) — Length of curve (m)
\( f \) — Allowable centrifugal acceleration (m/s²)
\( g_1 \) — Upgrade (%)
\( g_2 \) — Downgrade (%)

Explanation: The formula calculates the maximum comfortable speed based on curve geometry and acceleration limits.

3. Importance of Velocity Calculation

Details: Proper velocity estimation ensures safety, comfort, and efficient transportation system design.

4. Using the Calculator

Tips: Enter the curve length in meters, allowable acceleration (default 0.6 m/s²), upgrade (default 2.2%), and downgrade (default -1.5%).

5. Frequently Asked Questions (FAQ)

Q1: What's a typical centrifugal acceleration value?
A: For comfort, 0.6 m/s² is commonly used, but this can vary based on road type and design standards.

Q2: How do grades affect the velocity?
A: The greater the algebraic difference between grades (g1 - g2), the lower the comfortable velocity for a given curve length.

Q3: When would I need to calculate this?
A: When designing vertical curves to ensure safe operating speeds or evaluating existing curves for speed limits.

Q4: What units should I use?
A: Curve length in meters, acceleration in m/s², and grades in percentages.

Q5: Does this consider other factors like sight distance?
A: No, this only considers comfort factors. Always check for adequate stopping sight distance separately.