You need to disable editing using the settings of which ever feature service the map is sourcing that layer from.
If the feature service is hosted on ArcGIS Online, then this is done in the 'Settings' view of that feature service's details. In ArcGIS Online, find the feature service (not the map) in the Contents, then click on its name to see its overview, ...
Here are the options that I can think of:
Decommission the current road (#100) using the status field and create two new roads (#101 and #102).
The work order history will remain associated with the decommissioned road, not the new roads.
The road ID of the decommissioned asset could be stored in a decom_road_id field in the new roads.