41.5.1. Effective green time

Try these first

1. 1.

   What is effective green time?

   Hint

   Consider how green, yellow, and lost times play a role.

2. 2.

   Define lost time in the context of traffic signals.

   Hint

   Think about delays when the light changes.

3. 3.

   What is effective green time?

   • A. Total green light time
   • B. Total time for vehicles to move
   • C. Green time adjusted for lost times

   Hint

   Focus on how lost time influences total movement capacity.

4. 4.

   True or False: Lost time is only the time for the yellow light.

   • True
   • False

   Hint

   Consider what happens when a signal changes.

5. 5.

   A traffic signal allows for 35 seconds of green, 6 seconds of yellow, with 4 seconds of lost time. What is the effective green time, and how many vehicles can pass through if the saturation flow rate is 1000 vehicles/hour?

   Hint

   Use the formula for each part of the calculation.

6. 6.

   For a cycle length of 120 seconds and an effective green time of 45 seconds, with the lost times totaling 6 seconds, what is the saturation flow rate if the lane capacity is found to be 900 vehicles/hour?

   Hint

   Rearranging the capacity equation helps to find saturation flow.