Item Types - Begin & End Station of a line from reference alignment

Take a look at the Bentley example workspace. There is an example of the expressions you need in there.

• System.String.Format("{0:0+00.000}",CivilExpression.StationStart(this.Reference__x0020__Alignment)) & " [" & this.Reference__x0020__Alignment & "]"
• IIf (CivilExpression.OffsetStart(this.Reference__x0020__Alignment)< 0, System.String.Format("{0:0.00} Lt.",System.Math.Abs(CivilExpression.OffsetStart(this.Reference__x0020__Alignment))),System.String.Format("{0:0.00} Rt.",System.Math.Abs(CivilExpression.OffsetStart(this.Reference__x0020__Alignment))))

You will please note that if the line in question (curb, Guardrail, whatever) has gaps, then the end station will reflect the entire line and the stations at the gaps are not reported.

You will please note that if the line in question (curb, Guardrail, whatever) has gaps, then the end station will reflect the entire line and the stations at the gaps are not reported.

That seem problematic.  If the Station and offset item type does not pick up all the start and end point locations for guardrail or curb sections, it is not very helpful when using corridor modeling.  That is kind of the whole point, report all the start and stop locations of road / corridor features such as curb and guardrail. 

This is one of the reasons we moved to a Linear Template workflow for edges as our standard workflow (Corridors only from pavement edge to pavement edge). Similar to gaps in pavement components from Display Rules, the only real way to be able to automate the extraction of data like start/end Stations is to model with them in mind and start and stop Template Drops accordingly.