Stopping Or Non-Passing Or Headlight Sight Distance

Stopping Or Non-Passing Or Headlight Sight Distance

Stopping or non-passing or headlight sight distance is the distance required by a driver of a vehicle travelling at a given speed to bring his vehicle to a stop after an object on the road becomes visible. It is made of two components:

Stopping Or Non Passing Or Headlight Sight Distance

i) The distance travelled during the total reaction time i.e. the lag distance.
ii) Breaking distance

Therefore ,Stopping sight distance(Non Passing Or Headlight Sight Distance) = Lag distance + Breaking distance(in m)
= 0.278 Vt + V2/254f  .  

When there is an ascending gradient (+ n %) or descending gradient (- n %),the above equation becomes:

Stopping Sight Distance(Non Passing Or Head Light Sight Distance) = 0.278 Vt + V2/254(f ± 0.01n).  

On roads with restricted width or on single-lane roads when two-way traffic movement is permitted then the minimum stopping sight distance should be equal to twice the stopping sight distance calculated above.

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Overtaking Zone