TNMA LQ for Lecture 7

1. What is the primary objective of system optimal traffic assignment?

• (a) To ensure that every traveler experiences the same travel time

• (b) To assign all traffic to the path with the lowest free-flow travel time

• (c) To minimize the total system travel time

• (d) To ensure no user can improve their travel time by unilaterally switching routes

2. In a traffic network, the user equilibrium solution ensures that the travel time is equal on all used routes for each O-D pair.

• (a) True

• (b) False

3. 3. Under both the UE and SO principles, is it possible that some network links remain unused?

• (a) True

• (b) False

4. The figure shows a network with one origin-destination (O-D) pair and the corresponding link performance functions. The total demand for the O-D pair is 200 vehicles per hour (vph). Denote x₁, x₂, and x₃ as the traffic flows on link 1, link 2, and link 3, respectively. Which of the following flow patterns satisfies the user equilibrium (UE) condition?

• (a) x₁ = x₂=100, and x₃ = 0

• (b) x₁ = x₃ = 0, and x₂ = 200

• (c) x₁ = 150, x₂ = 50, and x₃ = 0

• (d) x₁ = x₂ = 0, and x₃ = 200

5. The figure shows a network with one origin-destination (O-D) pair and the corresponding link performance functions. Which of the following flow patterns satisfies the user equilibrium (UE) condition, if O-D demand is smaller than q'?

• (a) Only link 1 used

• (b) Only link 2 used

• (c) Both links used

• (d) Neither link is used