Planned event or incident signal timing

Planned event or incident signal timing synchronizes groups of traffic signals to favor traffic entering and exiting a special event venue or area in order to minimize congestion. It can also be used to divert traffic around an unplanned event, such as an incident or a regionwide evacuation.

Key characteristics




WSDOT regions

Other names

  • Special event signal timing
  • Incident response signal timing
  • Evacuation response signal timing

Strategy description

Planned event or incident signal timing can be used to manage traffic around events that cause non-recurring congestion. These include special events like concerts, sports games, air shows, or regional fairs, as well as unplanned events like incidents or evacuations.

Planned events draw a large number of visitors who all need to enter and exit a venue at similar times of day. This increase in people and motor vehicle traffic can cause congestion, resulting in long wait times. Typically, the goal for the planned event signal timing plans is to increase the length of the green light given to the vehicles entering and exiting the event.

For unplanned events, a traffic signal operator can activate event/incident signal timing plans to prioritize the traffic movements that will divert traffic around an incident or to evacuate people from the area.


Event managers, traffic agencies, public transportation agencies, and law enforcement work together to identify which vehicles and routes will need priority, organize communications during the event, and coordinate how to respond to unexpected incidents.

Real-time monitoring

Actual traffic conditions can be difficult to predict for planned events or incidents. For planned events, the start and end times vary and the popularity of the event impacts the number of people that will attend. For unplanned events, predicting the time an incident occurs is impossible. Therefore, an agency will typically monitor the event or incident traffic in real-time and adjust the signal timings to match the actual conditions. This often requires agency staff to work outside regular business hours to implement the planned event or incident signal timings.

Turning planned event or incident signal timings on and off

Planned event or incident signal timing plans are turned on and off manually by a person monitoring the traffic conditions. However, if traffic detectors are available, they can control event signal timings automatically. These detectors can measure an increase in traffic, time-of-day, or the number of parked vehicles in order to automatically activate a signal timing plan.

Common Operation Picture

A common operation picture (COP) is a continuously updated overview of an incident compiled throughout an incident's life cycle from data shared between integrated communication, information management, and intelligence and information sharing systems. The goal of a COP is real-time situational awareness across all levels of incident management and across jurisdictions.

When to use this strategy

Planned event or incident signal timing makes sense for:

  • Special events that substantially increase the number of people and vehicles entering and exiting a venue
  • Work zones or incidents that reduce the available number of lanes
  • Region-wide evacuations that increase traffic leaving an area

If the traffic signals can communicate with a central traffic signal system, the cost to use planned event signal timing plans are low— just requiring the cost of a staff member’s time to activate the signal timing plans and monitor the traffic conditions. If traffic signal communications equipment needs to be installed, the cost becomes more significant.

Strategy benefits:

  • Increases the length of the green light given to vehicles moving into and out of a venue, both before and after the event, to reduce vehicle travel times
  • Increases the length of the green light and capacity for vehicles diverting around an incident or evacuating an area
  • Allows traffic to flow smoothly and efficiently
  • Decreases emissions and fuel consumption

What you need in order to implement

Planning needs:

  • Analysis to consider the demand and congestion conditions, and determine appropriate signal timing strategies
  • Design to develop pre-programmed signal timing plans that favor specific movements

Coordination needs:

  • Coordinate with the event planners to plan and design the pre and post event strategy
  • Coordinate with public transportation to prioritize movements with buses or other forms of public transit
  • Coordinate with law enforcement and incident responders to plan roles and responsibilities for directing traffic, and to prioritize routes
  • Coordinate with affected traffic agencies to plan roles and responsibilities for traffic management strategies

Equipment needs:

  • Communications from traffic signals to a central operations center
  • Central traffic signal software
  • Vehicle detection to measure traffic volumes
  • Cameras for detection and monitoring

Agency resources needs:

  • Agency staff resources at hours outside normal business hours to turn on, adjust, and turn-off the special event signal timings

Learn more about this strategy

National Cooperative Highway Research Program Report 812, Signal Timing Manual.

About key characteristics

Location notes:

Implement near a special event venue that draws a significant increase in people and vehicles. 

Cost notes:

Cost can be low and limited to staff time if the traffic signals can communicate with a central traffic signal system. Cost can be medium if communications infrastructure needs to be installed so the traffic signals can communicate with a central traffic signal system.

Technology notes:

A traffic management center, central traffic signal system, intersection cameras, field traffic detection, and communications to the traffic signals is needed for effective event signal timings. This technology is common in most urban areas.

Collaboration notes:

Planned event signal timings may be operated solely by the traffic agency, but collaboration is typically needed with law enforcement, event managers, traffic and public transportation agencies to coordinate the event management.