The capacity flow (per lane) was 3200 vehicles/hour. The free mean speed on a roadway is 80 kmph. Estimate the average spacing between the vehicles under stopped condition.
- A6.05 m
- B6.15 m
- C6.25 mCorrect
- D6.35 m
Solution
Concept
Spacing at jam
Formula
q = vf kj/4
Step-by-step solution
1. kj = 4q/vf = 4 × 3200/80 = 160 veh/km. 2. Spacing = 1000/160 = 6.25 m.
Explanation
Using the parabolic flow-density relation.
Why the other options are wrong
Other spacings do not match.
Shortcut
kj = 4q/vf.
Correct answer: C) 6.25 m