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GATE 2022 CE (CE2) – Question 44

Traffic Engineering and Transportation Planning · Fundamental relationships of traffic flow · 2 marks · Multiple choice

A single-lane highway has a traffic density of 40 vehicles/km. If the time-mean speed and space-mean speed are 40 kmph and 30 kmph, respectively, the average headway (in seconds) between the vehicles is

  1. 3.00
  2. 2.25
  3. 8.33 × 10−4
  4. 6.25 × 10−4

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Correct answer: (A) 3.00

Explanation

The fundamental relation uses **space-mean** speed: $q=kv_s=40(30)=1200$ vehicles/hour.

Average time headway is $3600/q=\mathbf3$ seconds, **A**. Time-mean speed is not used in q=kv.