ArcGIS Roads and Highways allows you to view and analyze how routes, events, and intersections change over time out of the box. To support this functionality, all linear referenced data supports time. Routes, events, and intersections feature classes all have time columns that are managed and updated by Roads and Highways as route and event editing workflows are performed.
Time in the LRS
The following sample shows how features are affected when a route is edited. It also demonstrates how the time slider in ArcGIS Pro can be used to view the historic representation of a route.
Route 157A was created on 1/1/2000, so the From Date is 1/1/2000 and the To Date is <null> since it goes into the future.
| Route ID | From Date | To Date |
|---|---|---|
Route 157A | 1/1/2000 | <null> |
The route was realigned with an effective date of 5/10/2005. When route realignment was performed in Roads and Highways, two records were created: one for the original/historic route and another for the realigned/new route. This process is called time slicing. During the realignment, the following changes occurred:
- The original route feature was updated with a To Date of 5/10/2005.
- A new route feature was created with a From Date of 5/10/2005, using the same Route ID, with a different shape and calibration to reflect the realignment.
| Route ID | From Date | To Date |
|---|---|---|
Route 157A | 1/1/2000 | 5/10/2005 |
Route 157A | 5/10/2005 | <null> |
When the Apply Event Behaviors geoprocessing tool is executed, any events on the route that were impacted by the edit would also have similar time changes applied.
If you enable time on the layers in your project, you can use the time slider in ArcGIS Pro to view route changes over time. You can also use the time slider to view changes to event and intersection layers over time by enabling time on these layers in your project.
Time in other editing and loading scenarios
The following sections detail how time support in Roads and Highways impacts edits and event loading.
Time boxed editing
There are a few other editing scenarios in which time will impact the results of the edits.
If you edited a route in the past by choosing an effective date for an edit that is before the most recent To Date on the route, the edit will be boxed into the next To Date.
In the Route 157A example above, the result of the realignment was two records for the route.
| Route ID | From Date | To Date |
|---|---|---|
Route 157A | 1/1/2000 | 5/10/2005 |
Route 157A | 5/10/2005 | <null> |
If you were to perform a retirement to the beginning of the route with an effective date of 3/6/2003, the route would have three time slices after the edit:
| Route ID | From Date | To Date |
|---|---|---|
Route 157A | 1/1/2000 | 3/6/2003 |
Route 157A | 3/6/2003 | 5/10/2005 |
Route 157A | 5/10/2005 | <null> |
Notice that the retirement effective 3/6/2003 was only applied until the existing To Date (5/10/2005) on the record it was applied to (1/1/2000–5/10/2005). These same time changes would be applied to events and intersections on the route impacted by the edit. If the edit needs to be applied to route records beyond 5/10/2005, the edit can be performed on the 5/10/2005 – <null> record for the route as well.
Multiple edits on the same date to the same route
If you perform multiple edits with the same effective date on a route, it will result in routes and events with the same From and To dates, which don’t have a time range where they are active. Since these records don’t exist in time, they are deleted from the database.
The following example shows how features are affected when you perform multiple route edits with same effective date on the same route.
Route 8530B was created on 6/1/2010 and extended on 9/15/2015; this resulted in two records for the route.
| Route ID | From Date | To Date |
|---|---|---|
Route 8530B | 6/1/2010 | 9/15/2015 |
Route 8530B | 9/15/2015 | <null> |
The route was also realigned effective the same day as well (9/15/2015). After the route realignment was performed, instead of maintaining a record for the route with the extension, which has a From date of 9/15/2015 and a To date of 9/15/2015, the record was deleted and a new record was created that reflects both the route extension and realignment. The two records show the route before and after the extension and realignment.
| Route ID | From Date | To Date |
|---|---|---|
Route 8530B | 6/1/2010 | 9/15/2015 |
Route 8530B | 9/15/2015 | <null> |
The effect of time when loading events
Event feature classes in Roads and Highways also have time columns. When event records are loaded into event feature classes, they might have a different shape based on the underlying route’s time slices. The routes the events are located on are used to determine whether the event records need to be split by time.
For example, Route 550CH has two different records across time.
| Route ID | From Date | To Date |
|---|---|---|
Route 550CH | 4/15/2012 | 1/1/2016 |
Route 550CH | 1/1/2016 | <null> |
If an event with EventID 1601 on Route 550CH with a From date of 8/10/2014 and a To date of 12/31/2016 is loaded using the Append Events geoprocessing tool, the event will be split into two event records for the route across time and possibly having a different shape.
| Event ID | Route ID | From Date | To Date |
|---|---|---|---|
Event 1601 | Route 550CH | 8/10/2014 | 1/1/2016 |
Event 1601 | Route 550CH | 1/1/2016 | 12/31/2016 |