Design Speed for Horizontal Curves in Plains

The minimum value of ruling radius of horizontal curves in plains is dependent on the design speed. Therefore, to calculate the minimum value of ruling radius of horizontal curves in plains, the design speed is given by:

1. Determine the Design Speed:

The design speed is the maximum safe speed that can be maintained by vehicles on a particular road section under ideal conditions. It is determined based on several factors such as:

- Traffic volume
- Road alignment
- Geometric features
- Sight distance
- Terrain

The design speed is usually expressed in km/h or mph.

2. Calculate the Minimum Value of Ruling Radius:

Once the design speed is determined, the minimum value of ruling radius can be calculated using the following formula:

Rmin = V^2 / (127f)

Where:
- Rmin is the minimum value of ruling radius in meters
- V is the design speed in km/h
- f is the coefficient of friction between tires and road surface

The coefficient of friction is usually taken as 0.15 for dry asphalt surfaces and 0.10 for wet surfaces.

3. Consider Other Factors:

While calculating the minimum value of ruling radius, it is important to consider other factors such as:

- Superelevation of the road
- Width of the road
- Sight distance
- Grade of the road
- Presence of obstacles

These factors can affect the safe speed that can be maintained on a particular road section and, therefore, the minimum value of ruling radius.

In conclusion, the minimum value of ruling radius of horizontal curves in plains can be calculated by determining the design speed and using the formula Rmin = V^2 / (127f). However, it is important to consider other factors that can affect the safe speed that can be maintained on a particular road section.

16 kmph