Question

Relationship between traffic speed and density is described using a negatively sloped straight line. If \( v_f \) is the free-flow speed, then the speed at which the maximum flow occurs is:

• A. 0
• B. \( \frac{v_f}{4} \)
• C. \( \frac{v_f}{2} \)
• D. \( v_f \)

Hint:

In traffic flow theory, maximum flow occurs when the traffic speed is half of the free-flow speed for a linearly decreasing speed-density relationship.

Answer 1

The Correct Option is C

For a negatively sloped speed-density curve, the maximum flow occurs when the speed is half of the free-flow speed \( v_f \). This is a standard result from traffic flow theory.
Final Answer: \[ \boxed{\frac{v_f}{2}}. \]