The Comparison Report - LRMs report provides a comparison of the LRMs in the system as it was just prior to running the interface compared to the contents of the buffer tables loaded by the interface run. It is primarily used with Test Mode interface runs so that the changes that would be made by a Full Mode interface run can be evaluated.

Each changed Base LRM route/Alternate LRM route combination that contains alternate LRMs is displayed in its own row containing the following information:

• Alternate LRM Name – This is the name of the alternate LRM referred to by this row. There may be multiple Linear Referencing Methods configured in a system. This field indicates which one is covered in each line.
• Base Route Name – This is the name of the base LRM route referred to by this line.
• Alt Route Name – This is the name of the alternate LRM route referred to by this line.
• Current: LRM Measures – This field shows the ranges of measures on the base LRM route that corresponds to a range of measures of the alternate LRM route as it was just prior to running the interface.
• Buffer: LRM Measures – This field shows the ranges of measures on the base LRM route that corresponds to a range of measures of the alternate LRM route as it exists in the buffer table that was loaded by the interface.
• Error Text – This displays any errors that were detected in trying to locate the changed version of the LRM against the changed version of the LRS. The possible values for this field and their meanings are:
  • This LRM does not occur on one of the new routes – LRM sections must occur on a route
  • The start of this LRM (<LRM start>) occurs before the start of the route (<route start>) – LRM sections must occur on a route
  • The end of this LRM (<LRM end>) occurs after the end of the route (<route end>) – LRM sections must occur on a route
  • The LRM (<LRM start>/<LRM end>) overlaps a gap (<gap start>/<gap end>) – LRM sections must occur on a route
  • The LRM (<LRM start>/<LRM end>) overlaps a subordinate section (<concurrency start>/<concurrency end>) – LRM sections must occur on a route
  • The start measure of this LRM is greater than the end measure – Measures should always go from lower values to higher values
  • The start measure of this LRM is null – Start measure is a key field that should never be null
  • The end measure of this LRM is null – End Measure is a key field that should never be null
  • The route name of this LRM is null – Route name is a key field that should never be null
  • This LRM (<LRM route name>|<LRM start>/<LRM end>) overlaps this LRM (<LRM route name>|<LRM start>/<LRM end>) – LRM sections should never overlap as this would indicate that the same alternate LRM section is assigned to more than one base route location
  • The measure ranges differ by <measure difference> – As both sides of an LRM record represent the same section of road, it is expected that both sides will have the same length; this indicates an issue with calibration
• Status – This field shows the word “Change” if the values on the Current LRS fields differ from the values of the LRS Buffer fields. This field shows the word “Error” if the route did not change but exhibits an error. Otherwise this field is blank. By default, a filter is applied based on this field to show only rows where this field is not null.