Question

The absolute minimum sight distance required for stopping a vehicle moving with a speed of 80 km ph, is ____________

(a) 100 cm

(b) 120 cm

(c) 40 cm

(d) 60 cm

I have been asked this question in an interview for internship.

This interesting question is from Detailed Specifications of Road Work topic in section Specifications, Estimation of Quantities of Materials and Transport of Civil Engineering Drawing

Answer 1

Correct answer is (b) 120 cm

For explanation I would say: SSD = lag distance + braking distance.

= v.t + v^2/2gf.

= 22.22*2.5 + (22.2)2/(2*9.81*0.35).

= 126.5 (near to 120)

Where v is in m/s and t = reaction time(2.5sec acc. to IRC).