41.5.2. Lane capacity

Try these first

1. 1.

   What is lane capacity?

   Hint

   Think about how vehicles are counted.

2. 2.

   Define effective green time.

   Hint

   Consider what happens when the signal changes.

3. 3.

   What is the formula to calculate lane capacity?

   • c = g / C
   • c = G - L
   • c = s * t

   Hint

   Think about how to find capacity.

4. 4.

   True or False: Effective green time includes lost time.

   • True
   • False

   Hint

   Consider what effective means.

5. 5.

   A city intersection has a saturation flow rate of 1750 vehicles/hour. During peak hours, the cycle time is 70 seconds with an effective green time of 40 seconds. Calculate the lane capacity and discuss its implications on intersection design.

   Hint

   Follow the capacity formula to derive your answer.

6. 6.

   In a new traffic signal design, loss time during signal change is projected to be 5 seconds. How would you account for this in your lane capacity calculation if the green time remains unchanged?

   Hint

   Always consider how lost time affects total available time for vehicles.