## Calculate Stopping Sight Distance

**Mathematical Example**

Calculate stopping sight distance for

i) Two lane road with two way traffic.

ii) Single lane road with two way traffic.

Design speed is 50 Km/h, Coefficient of friction is 0.4, and the reaction time of the driver is 3 sec. The road is level.

## Mathematical Solution of Stopping Sight Distance

Given, design speed (V) = 50 Km/h, reaction time of driver(t) = 3 sec, coefficient of friction between tire and road surface(f) = 0.4

We know, for descending gradient,

Stopping sight distance = (0.278V.t + V²/254f)

= 0.278 ⨯ 50 ⨯ 3 + 50²/254 ⨯ 0.4

= 66.3 m.

Answer:

Stopping Sight Distance

i) For two-lane road with two way traffic = 66.3 m

ii) For single lane road with two way traffic = 2⨯66.3 = 132.6 m

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