The speed of overtaking and overtaken vehicles are 20 m/s and 10 m/s respectively. The time taken in overtaking operation is 8 sec. The reaction time for overtaking is 2.0 sec. Calculate the safe overtaking sight distance for the one-way road.
- A124 m
- B125 m
- C126 mCorrect
- D127 m
Solution
Concept
OSD one-way
Formula
OSD = d1 + d2
Step-by-step solution
1. d1 = vb t = 10 × 2 = 20 m. 2. s = 0.7 vb + 6 = 13 m. 3. d2 = vb T + 2s = 10 × 8 + 26 = 106 m. 4. OSD = 20 + 106 = 126 m.
Explanation
For a one-way road d3 is not required.
Why the other options are wrong
Other values do not follow.
Shortcut
d1 + d2.
Correct answer: C) 126 m