[It seems that as GIS-T professionals, we are cursed to build or maintain LRS castles on sand dunes to fulfill the LRS promise of integrating and managing all transportation events across an enterprise.  

Indeed, LRS networks represent dynamic roadway systems.  Roadway construction, route definition revisions, or corrections to centerline representations result in route measure changes.  To keep event locations intact, an automatic mechanism – measure synchronization – is required to update measures of events affected by the route changes (Figure 1).

Figure 1. Measures of the crash before and after route extension

However, cost for development or configuration aside, measure synchronization is not the solution to the shifting sands issue for two important reasons:


  1. External synch: Cascading synchronization on events stored and managed in other data silos (safety, bridge, or pavement management systems) poses a significant technical and managerial challenge.


  1. Fault recovery:  Should measure synchronization fails against one or more event layers, due to misconfiguration or a system hiccup, recovery from the failure becomes dicey.  This is because the context in which the synchronization parameters exist is no longer available.  

Can we on earth prevent our dream LRS castles from crumbling?  Fortunately, route reference is here to help, once again. 

In Figure 2, the same crash referenced to D Street is not impacted before and after the route extension.  With route reference, there is no need for measure synchronization.

Figure 2. Crash location remained unchanged after route extended

Route reference not only breathes a touch of humanity into LRS but also turns the desert dunes into an oasis with solid ground on which LRS castles may thrive.   

Next article we will take a deep dive into route reference – Building Magic Layer: Secret Sauce Unveiled.