1. What is Stopping Sight Distance?

Stopping Sight Distance (SSD) is defined as the distance provided on the road before a sharp turn or obstacle to allow a vehicle to stop safely. It consists of the sum of the breaking distance and lag distance.

2. How Does the Calculator Work?

The calculator uses the SSD equation:

Where:

• \( SSD \) — Stopping Sight Distance (m)
• \( BD \) — Breaking Distance (m)
• \( LD \) — Lag Distance (m)

Explanation: The breaking distance is the distance traveled after applying brake till the vehicle stops. The lag distance is the distance travelled by the vehicle before applying the break and after seeing the object.

3. Importance of SSD Calculation

Details: Accurate SSD calculation is crucial for road design, traffic safety analysis, and determining safe driving distances. It helps ensure that drivers have sufficient distance to stop safely when encountering obstacles or sharp turns.

4. Using the Calculator

Tips: Enter breaking distance and lag distance in meters. Both values must be non-negative numbers.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect breaking distance?
A: Breaking distance is influenced by vehicle speed, road conditions, tire condition, brake efficiency, and vehicle weight.

Q2: What is included in lag distance?
A: Lag distance includes the distance traveled during the driver's perception time and reaction time before applying the brakes.

Q3: How is SSD used in road design?
A: SSD is used to determine minimum sight distances required on highways and roads to ensure safe stopping capabilities for drivers.

Q4: Does weather affect stopping sight distance?
A: Yes, adverse weather conditions like rain, snow, or fog can significantly increase both perception-reaction time and breaking distance.

Q5: How does vehicle speed affect SSD?
A: SSD increases with the square of the speed - doubling the speed quadruples the required stopping distance.