Introduction to the design parameter terms of traffic signal control
1. cycle time
It refers to the total time in which the intersection signal allocates one passage time in sequence (phase) to all intersections of the intersection.
2. phase
That is, the signal phase refers to the sequence group of green light passage rights set according to the requirements of the intersection and in sequence within a certain period of time.
3. offset
In coordinated control, the difference between the start time or end time of the phase between the specified reference intersection and the coordinated intersection.
4. Signal Light group
A complete combination of red, yellow and green three-headlights for vehicles or red and green two-headlights for pedestrians.
5. green conflict
The green signal lights that are not allowed to be released simultaneously should be illuminated at the same time as those that are allowed to be released.
6. minimum green time
The minimum safe time that the phase green light signal must be turned on.
7. maximum green time
The maximum duration for which the phase green light signal is allowed to be on.
8. Green Split
It refers to the ratio of the effective green light time within each phase within a cycle to the cycle.
9. Saturation Flow Rate
It is an important parameter for measuring the traffic flow capacity at intersections. It usually refers to the maximum continuous traffic volume passing through an intersection within a green light period.
10. Flow Ratio
It is the ratio of the actual flow to the saturated flow. It is not only an important parameter for calculating signal timing but also a criterion for measuring the congestion level at intersections.
11. Intergreen Time
It refers to the time taken from the end of the green light for the phase where the right of way is lost to the start of the green light for the next phase where the right of way is gained.
12. Effective Green Time
It refers to the actual vehicle passage time that is effectively utilized. It is equal to the sum of the green light time and the yellow light time minus the loss time for the lead vehicle to start.
13. Delay
It refers to the time loss caused to vehicles due to traffic conflicts or restrictions on signal control facilities. It is an important parameter for calculating signal timing and evaluating the traffic effect at intersections, and is also often used as a crucial parameter for determining the performance of signal control systems.
14. signal light group
A complete combination of red, yellow and green three-headlights for vehicles or red and green two-headlights for pedestrians