I'm a fairly experienced ArcGIS 10 user, but am new to Linear Referencing.
I have a road segment dataset, stored as a simple line feature class in File Geodatabase, and I have a table of "events" in the same geodatabase.
The road lines have a Segment_ID attribute, and also a Section_Length.
The events table have the same Segment_ID along with other information, including a "Length" attribute which we want to use to dynamically segment each road segment at that chainage.
My understanding (which may be wrong!) is that we have to use the "Create Routes" tool followed by "Create Route Event Layer" which will segment the lines at the chainages defined in the "event" table.
The problem seems to be that the direction of the lines (which are highways with specific directions of travel) in the original feature class are ignored when creating the Routes, apparently necessitating a manual edit to ensure they are correct.
How can this be avoided to perform the linear referencing?
Best Answer
If your roads are digitized in the correct direction (the direction you need your measures to follow), you can add a new field (Type: long int, Name: From) to your road Feature Class.
Then calculate the new field to the value 0 (zero) for all the features.
Now, in your Create Routes tool, you choose the "Measure Source" to "TWO_FIELDS" and select the From (From Measure Field) and Section_length (To Measure Field) fields. This way the routes get the digitalization direction, as their measure direction.