GATE 2018 CE (CE2) – Question 63

Traffic Engineering and Transportation Planning · Fundamental relationships of traffic flow · 2 marks · Numerical answer

Space-mean speed and density are linearly related. Free-flow speed is 80 km/h and jam density 100 vehicles/km. At 40 km/h, traffic flow, to one decimal, is ______ vehicles/h.

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Correct answer: 2000.0 to 2000.0

Explanation

Greenshields relation gives $40=80(1-k/100)$, hence k = 50 vehicles/km. Flow is $q=kv=50(40)=2000$ vehicles/h.