Trigger Boxes

Trigger boxes create areas around a stop that trigger actions that occur when a vehicle enters or exits that geographic area. When new stops are added to a scheduling package, the schedule data files are imported into myAvail, and a trigger box is automatically assigned to that location. The planner who has proper access permissions will need to review it and add any in-vehicle actions that should occur automatically.

The Geographic Tools tab provides a graphical tool you can use to create, modify, and review trigger boxes. You can also modify the shape of the trigger box, control functions that occur, and make pattern-specific adjustments. myAvail displays trigger boxes on the map, as shown below.

Trigger boxes are geofences, or virtual boundaries, that are defined around stops. The in-vehicle equipment executes functions when vehicles enter and exit trigger boxes. The in-vehicle equipment performs the following routine functions for every trigger box:

  • Checks entry heading: If myAvail specifies a compass heading, the vehicle verifies that the direction of travel is within 15 degrees of the setting. This verification allows vehicles to ignore trigger boxes that they pass through multiple times on a trip and to execute the associated functions only once.
  • Announcements: If an announcement is set, it will be made on entry or exit.
  • Setting the headsign: Trigger boxes can override the trip’s headsign value on entry or exit.
  • Changing the Traffic Signal Priority (TSP) setting: If configured, the TSP setting toggles on entry or exit.
  • Headway time point: Headway time points assess the interval between vehicles on a Headway scheduled route. This value is usually set by the stop, but pattern-specific trigger boxes can override it.
  • Time point override: Time points assess the schedule adherence of vehicles on scheduled routes. This value is usually set by the stop, but pattern-specific trigger boxes can override it.
  • Schedule Adherence report: Reports the departure time, dwell time, passenger boards, and alights for the stop and location, speed and direction of the vehicle when the report is made.
  • Changing farebox settings: When starting a new trip, the system can update the farebox, if equipped, with the route, trip, and fare type.

Before you can use the trigger box tools, you must satisfy the following prerequisites:

  • Announcements are ready to assign to stops.
  • You know how the vehicle approaches the stop.
  • You know whether a layover or vehicle movement occurs at the stop before departure.
  • You know whether the headsign changes.
  • You know whether there is a unique usage of any stop that is contained in multiple routes or patterns.

Examples of In-Vehicle Actions

The In-vehicle actions usually occur during the entry of the trigger box, but you can set them to happen while exiting. Typically, internal announcements audibly identify a stop as the bus approaches while the interior LED sign displays the stop information. You can associate the text with recordings using the Announcements section. Internal announcements can also call attention to a point of interest or public service announcements. Internal announcements must be set up in compliance with ADA regulations.

The headsign controls set the external vehicle signage, which allows the vehicle to display the departing destination as the vehicle approaches the stop without driver interaction.

When a stop is at the end of a trip, entering the trigger area can notify the system to adjust the trip and route setting in the farebox if necessary.

If your vehicles are equipped with Traffic Signal Priority (TSP), you can toggle the state of the TSP. If TSP is active, it becomes inactive, or vice versa. This does not require driver interaction.

Examples of Reporting Actions

By default, all Reporting Actions occur when the vehicle exits a trigger area. These actions do not require operator interaction.

Vehicles send the Schedule Adherence reports to the central system and contain information, such as Stop ID, GPS information, time departed, duration at the stop, and the number of passengers boarding and alighting. If the vehicle is in communication with the central system, it sends this information in real time. Otherwise, the vehicle stores the information and sends it when communication is restored. myAvail uses the schedule adherence information to estimate the departure time of future stops.

Headway Time Point and Time Point Override are set for a stop in stop definitions. myAvail uses them to make schedule adherence calculations. These values override the generic values and create a value specific to a given pattern in a route.

Vehicles can enter a trigger box in both the inbound trip and the outbound trip, but it is active for only one of the two trips.

Trigger Box Map Symbols and Borders

The symbols that represent the stop location and the color of the trigger box border and fill convey important information about the stop and review status.

Description of Trigger Box Properties Appearance
Clock symbols represent stops that are time points. myAvail displays the clocks on the map at the physical locations of the stops.

Gray dots represent the physical location of stops that are not time points.

Black borders represent stops that are announcement points.

Gray borders represent stops that are not announcement points.

Dashed lines represent stops for pattern exceptions. These are trigger-box-specific patterns.
      • Black dashed borders represent announcement points.
      • Gray dashed borders represent non-announcement points.

Trigger boxes with red fill have not been reviewed.


Creating Default Trigger Boxes

With the click of a button, you can create trigger boxes for all routes and all patterns. If at least one stop does not have a trigger box, myAvail displays the Create Missing Boxes button. Click this button and all stops that do not have a trigger box are assigned a default-sized trigger box. These default trigger boxes do not have announcements, entry headings, or headsign values.

NOTE: The button indicates the number of stops missing a trigger box.

Reviewing Trigger Boxes: Best Practice

  1. Click the Review Trigger Boxes button. This button is a built-in shortcut. Any unreviewed trigger boxes will display in a list. 
  2. myAvail automatically displays a list of all trigger boxes that have not been reviewed. Unreviewed trigger boxes are indicated in red, to avoid losing sight of them.
  3. Click to select one and the software will automatically display its location, making it ready for editing.                                                                                                                                                    
  4. Select an entry in the list to load the global pattern for the selected route and direction. myAvail displays the stop on the map and in the data grid.
  5. Review all fields for the trigger box in the data grid to ensure that they are correct.
      • Trigger box shape
      • Announcement values (if any)
      • Entry Heading
      • Headsign value (if any)
      • Headway Time Point
      • Time Point Override
      • TSP value
  6. If you modify any of these values, myAvail checks the trigger box as reviewed.
  7. If no values need to be changed, manually check the Reviewed box.
TIP: A route and direction can have several trigger boxes that you need to review. Instead of using the Review Trigger Boxes button, use the map tool to quickly scan for these trigger boxes.

Modifying Trigger Boxes

  1. Select either the Future or Current schedule to modify it (See Schedule Choice). The default is set to Future, for user ease.
  2. Select the Route containing the trigger box you need to modify.

3. Select the Direction. Direction labels are configurable by your property. Many properties use I for Inbound and O for Outbound and L for Loop. However, there are many other options possible including directional (North, South, East, West, Clockwise Loop, Counterclockwise Loop, …)

4. Select the Pattern. A bold pattern name indicates that the pattern has at least one pattern-specific trigger box. When you select a pattern, you can choose either the global pattern or a specific pattern.

Consider the following when choosing a Global pattern:

      • Global includes all stops in the selected direction, which load in the order they are assigned to the route.
      • Global is good for a general review and adjustments when you are not looking for a specific problem or you do not need to make a pattern-specific change.

Consider the following when choosing a Specific pattern:

      • Selecting a pattern loads the stops in pattern order; how the vehicle will pass through the trigger boxes.


5. Choose Append or Overwrite.

6. Click Load Data. The map area and data grid display the trigger boxes that match your criteria.           

7. Select the trigger box that you need to edit. You can select it by clicking it on the map, clicking it in the grid, or using the search function.

If you use the Search for a Stop Name drop-down list, type the first few letters of the stop name in the entry field. The software uses pattern matching to generate a list of stops that match the letter combination you entered.

8. After you select a trigger box, myAvail highlights the data grid row and opens a quick entry box in the corner of the map area.

CAUTION: To make pattern-specific changes, you MUST check the Pattern Specific checkbox before you make any changes. This checkbox is located on the far right side of the grid.

9. Enter the required values directly into the data grid on the highlighted line. The columns that allow data entry are the following:

      • Announcement (Optional): Select the name of an announcement to assign it to that trigger box.
      • Announcement Entry/Exit (Optional): Use this field to control when the vehicle plays announcements. If this field is blank, the announcement plays when the vehicle enters the trigger box, which is by far the most common case. Selecting Exit causes the announcement to play when the vehicle exits the trigger box.
      • Heading: This is the compass heading of the vehicle when it enters the trigger box. The compass heading has an allowance of 15 degrees on either side, to account for potential error.
TIP: Compass headings are usually required only when vehicles pass through a trigger box more than once on a single trip. Consequently, you do not need to specify headings for most trigger boxes. In rare cases, you can specify a compass heading to intentionally delay trigger box entry functions for large trigger boxes.

Suppose vehicles enter a large trigger box for a shopping center heading north. You do not want to trigger the in-vehicle functions until the vehicle turns west to approach the stop. In this case, specify a westbound compass heading.

NOTE: myAvail’s compass tool is discussed further in the next section.
      • Headsign: Enter the headsign code associated with the trigger box. This is the same code that operators enter manually. Enter this for only the last stop of the pattern.
      • Headsign Entry/Exit: Use this field to control when the vehicle changes the headsign. If this field is blank, the headsign changes when the vehicle enters the trigger box, which is by far the most common case. Selecting Exit causes the headsign to change when the vehicle exits the trigger box.
      • Headway Time Point: If you select Yes for a stop, the vehicle sends a headway report to the central system. The central system uses headway reports to calculate the schedule deviation, which is calculated only for stops with this attribute. If you leave this field blank, it is the same as selecting No. No time point reports are sent for this stop.
      • Time Point Override (Optional): If you select Yes for a stop, the stop is designated as a time point. Usually, you assign this attribute when you define the stop, where it applies to all routes and patterns that use the stop. Only select Yes when you need to override this attribute for a given route or pattern. This column is rarely used. If you leave this field blank, it is the same as selecting No. No override occurs.
      • TSP: If you leave this column blank, no action is taken. Most properties do not use traffic signal priority (TSP) and should not use this column. For properties that use TSP, if you choose either Yes or No, the trigger box toggles the operational status of the TSP device when a vehicle passes through the box. If the TSP device is on, it will be shut off, and vice versa. Yes and No issue the same command for this field only. Leave this column blank if you do not want to change the TSP status. You must understand the specific conditions and locations where this feature may be used.
      • TSP Entry/Exit: Use this field to control when the trigger box toggles the status of the TSP device. If you leave this field blank, the TSP toggles when the vehicle enters the trigger box. Selecting Exit causes the TSP to toggle when the vehicle exits the trigger box.
      • Pattern Specific: If you check this box, all changes that you make are specific to this trigger box. You can check this box only when you select a Specific pattern in step 8. Changes that you make before checking this box are applied globally to all routes and patterns that use this stop.
CAUTION: If the checkbox is checked and you uncheck it, all fields revert to the global settings. The results of unchecking the box cannot be undone other than by manually re-entering the pattern-specific values.
NOTE: Avail strongly recommends not doing Pattern Specific trigger boxes on trip change time point stops. These stops are simultaneously the last stop of one pattern and the first stop of another.
      • Reviewed: If you modify any of the field values, myAvail automatically checks the trigger box as reviewed. If no values need to be changed, manually check the Reviewed box. You can also uncheck this box if you want to go back later and fix a problem. However, all trigger boxes must be reviewed before running the Run Schedule File Builder (RSFB). If there are any trigger boxes that are not marked as reviewed, a warning is displayed after clicking Build Run Files. To view a list of trigger boxes that need to be reviewed, click Check Triggers on the menu of the main form.

Using the Compass Tool to Fill In the Heading Field

  1. Click the Show Compass button.
  2. Place the compass outside the trigger box on the side where the vehicle enters the trigger box.
  3. Identify the heading that is the closest match to the entry heading, or, where the vehicle will enter the trigger box location. Enter this value in the     Heading field. In the example, the closest match is 292.5 degrees.
  4. Click Hide Compass to remove its display on the map.

Trigger Box Demo Video

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