Scenario-Based ManagementScenario-Based Queue and Discharge Management
Respond to Congestion Across the Related Junction Network, Not at a Single Junction
ISSD Scenario-Based Queue and Discharge Management is a traffic management solution that evaluates real-time congestion at mutually influencing junctions at network level and enables the signal plans of the relevant junctions to be adjusted together.
The system does not attempt to relieve a congested direction simply by assigning it a longer green time; it also evaluates the approaches feeding vehicles into that direction, upstream junctions, junction exits, and downstream traffic conditions. Queue length, average speed, and travel time information obtained from FCD are combined within a common decision structure with exit occupancy and discharge data from VIERO-Discharge cameras.
Scenario-Based Queue and Discharge Management
Scenario-Based Management is a management mode that treats related junctions as a common traffic network and changes the signal plans of multiple junctions together when defined congestion conditions occur. The system does not regard a queue at one junction as a problem belonging only to that junction.
It also evaluates the approaches feeding vehicles into the queue, the volume of traffic arriving from upstream junctions, road capacity in the exit direction, occupancy at downstream junctions, travel time between junctions, and the risk of the queue propagating through the road network. In this way, the source of congestion, the directions it affects, and the road sections through which it can be discharged are managed together.
From queue detection to scenario execution, step by step
Ecosystem Connection
System capabilities
Scenario-Based Management combines queue and discharge data within a single decision structure at network scale.
Key Features
Applicable Traffic Scenarios
Coordinated signal plan scenarios that can be predefined for different congestion and incident conditions.
Advantages
Scenario-Based Queue and Discharge Management aims to prevent corridor gridlock by responding to congestion at network scale through predefined scenarios.
Frequently Asked Questions
What does Scenario Management do? +
It evaluates queue and exit occupancy problems at related junctions together and enables the signal plans of multiple junctions to be adjusted in coordination.
Which data does the system use? +
The system primarily uses speed, travel time, and queue information obtained through FCD together with exit occupancy and discharge data generated by VIERO-Discharge.
What does VIERO-Discharge measure? +
VIERO-Discharge evaluates vehicle flow and occupancy on junction exit directions and whether vehicles can move away from the junction.
Is more green time always assigned to the congested direction? +
No. The system first checks whether there is sufficient space for vehicles to proceed at the relevant exit. If the exit is full, providing more green time may cause blockage.
Does the system intervene only at the congested junction? +
No. Upstream and downstream junctions related to the congested junction, as well as approaches feeding vehicles into that direction, can also be managed together.
What is a coordinated signal plan change? +
It is the modification of cycle length, green time, phase priority, or active signal plans at multiple junctions associated with the same traffic problem under a single scenario.
Can the system prevent queues from propagating from junction to junction? +
It can apply traffic inflow control and downstream discharge scenarios using FCD and exit occupancy data. This structure supports the reduction of queue propagation.
Can scenarios be activated automatically? +
Yes. The relevant scenario can be activated automatically when defined speed, travel time, queue, and occupancy thresholds are met.
Can an operator activate a scenario manually? +
Yes. Traffic management center operators can manually activate scenarios during events, accidents, disasters, or planned works.
What happens when traffic returns to normal? +
When queue, speed, and exit occupancy values return to defined levels, the active scenario is terminated and the junctions are switched to the appropriate standard operating mode.
How does it differ from isolated dynamic management? +
In isolated dynamic management, each junction operates independently according to its own traffic conditions. In Scenario-Based Management, the signal plans of mutually influencing junctions are adjusted together at network level.
How does it differ from Dynamic Coordination? +
Dynamic Coordination aims to create orderly flow and a green wave along a corridor. Scenario-Based Management applies coordinated signal plan interventions to specific traffic problems such as queues, exit occupancy, and blockage.
Does the system directly operate the traffic signals? +
Scenario decisions are generated on MANGO. Plan and timing information is transferred to junction controllers through CENTRIS. Traffic signals are operated by the junction controllers.