Events data model

Disponible avec la licence Location Referencing.

Events are managed in ArcGIS Roads and Highways in feature classes called event feature classes, which are registered in the same geodatabase as the linear referencing system (LRS).

Roads and Highways manages the shape of the feature based on the route, measure, and to and from dates. The required source event data differs depending on the event type being registered. The required fields for each event type are listed in the following sections.

Remarque :

Event feature classes can be modeled in advance or created when registering the event in the LRS. If modeled in advance, ensure that the spatial reference and x,y-, z-, and m-tolerance and resolution of the event feature class match that of the network in which it's registered.

Learn more about tolerance and resolution settings for the LRS

Minimum event fields

The minimum event fields are as follows:

Field	Data Type	Length	IsNullable	Description
Event ID	String	Between 32 and 255	No	The unique ID for each event record.
Route ID	String	Same length as the Route ID field in the centerline sequence table	No	The unique ID for each route in the network.
From Date	Date	8	Yes	The date that the event becomes active on the route.
To Date	Date	8	Yes	The date that the event is retired on the route.
Measure (point events only)	Any Numeric		No	The measure on the route where the event is located.
From Measure (line events only)	Any Numeric		No	The measure on the route where the beginning of the event is located.
To Measure (line events only)	Any Numeric		No	The measure on the route where the end of the event is located.
Location Error	String	100	Yes	The location error for the event.

Event referent fields

When registering events, you can store the event location based on its offset from another location. The offsets can be based on x- and y-coordinates, a station, the length from the beginning of an event, other LRS events, intersections, or another point feature class.

To enable storing referent locations with an event, the following fields are required:

Field	Data Type	Length	IsNullable	Description
Referent Method (point events only)	Short Integer	5	Yes	The method for referencing the offset feature. This can be x,y coordinates, stationing, length, LRS Network, event, intersection, or other point feature classes.
Referent Location (point events only)	String	Between 50 and 255	Yes	The location of the offsetting feature. This can be an x,y coordinate, feature or event ID, or intersection ID.
Referent Offset (point events only)	String	Between 50 and 255	Yes	The offset measure. Saved in the unit of measure configured when registering an event and configuring the offset fields.
From Referent Method (line events only)	Short Integer	5	Yes	The method for referencing the offset feature. This can be x,y coordinates, stationing, length, LRS Network, event, intersection, or other point feature classes.
From Referent Location (line events only)	String	Between 50 and 255	Yes	The location of the offsetting feature. This can be an x,y coordinate, feature or event ID, or intersection ID.
From Referent Offset (line events only)	String	Between 50 and 255	Yes	The offset measure. Saved in the unit of measure configured when configuring offset fields.
To Referent Method (line events only)	Short Integer	5	Yes	The method for referencing the offset feature. This can be x,y coordinates, stationing, length, LRS Network, event, intersection, or other point feature classes.
To Referent Location (line events only)	String	Between 50 and 255	Yes	The location of the offsetting feature. This can be an x,y coordinate, feature or event ID, or intersection ID.
To Referent Offset (line events only)	String	Between 50 and 255	Yes	The offset measure. Saved in the unit of measure configured when configuring offset fields.

Stationing event fields

When registering an event that uses stationing, all of the fields from a Route and Measure point event are required in the source event data. The following fields are required for an event that uses stationing:

Field	Data Type	Length	IsNullable	Description
Station	String	Any	Yes	The stationing value for the station.
Back Station	String	Any	Yes	The back stationing value for the station. This value is populated when an equation point is present at the station location.
Station Direction	String	Any	Yes	The field used to designate if stationing values increase in the opposite direction of the increase in measure on routes.

Event types

Roads and Highways has two types of events: those stored in the same geodatabase as the LRS and those in external databases. Events in the geodatabase are stored as feature classes, while external events are stored as tables in an RDBMS database or geodatabase (other than the geodatabase in which the LRS resides).

Events can be registered as line or point events in the LRS geodatabase for an existing LRS Network using the Create LRS Event tool.

Learn more about creating and modifying LRS events

External events from an external data source can be registered as line or point events for an existing LRS Network using the Configure External Event With LRS tool.

Remarque :

If your event feature class is modeled in advance, its spatial reference, x,y, z-, and m-tolerance and resolution must match its associated network.

It is also recommended that you index your project items to improve event table performance when registering events.

Learn more about tolerance and resolution in ArcGIS Roads and Highways.

Events in the geodatabase

In addition to the location of the data source, internal and external events also differ with respect to how they are managed after registration.

Events in the LRS geodatabase are stored as feature classes and the shape of the event features are managed based on the route, measure, and to and from dates. This provides increased performance in ArcGIS for mapping and spatial query of the event data.

When registering an event in the LRS geodatabase, you can model the feature class in advance in the geodatabase with the LRS and have the new feature class created for you in the geodatabase with the LRS. You can also copy the schema from another table or feature class to the new feature class created in the LRS geodatabase.

Learn more about creating and modifying LRS events

After event registration, the event is automatically managed. When edits are made to a route, the changes are made directly to the event feature class using the event measure behavior configuration. When the event layer is refreshed in your map, which is automatically triggered by an edit activity, you can see the updates immediately.

After performing and saving edits using the tools on the Location Referencing toolbar, run the Apply Event Behaviors tool to update the event locations.

External events

Connections to external event tables are not modeled in the geodatabase. When an event table or feature class outside of the LRS geodatabase is registered as an external event table, it is assumed to be a read-only connection and the changes are not written directly to the external event table. There may be business rules associated with updating measures on events in an external system, so events in external systems are not directly modified.

A log of all the edits performed that have an impact on event measures is maintained. You can use web services to send these updates to the external table or feature class to apply measures.

Learn more about registering an external event