Plotting new offset points in ArcMap

Question

I have a task where I have plotted positions along an alignment (see red dots in images) and I need to plot two offset points (from the chainage locations) at varying distance parallel to the alignment (see image 2). I am not sure how to go about it.

I have thought about:

• working out the direction of the line and from that,
• then working out what the offsets x,y should be using trigonometry,
• create new points for the offset using the results of the trigonometry.

I was also thinking of:

• creating a 1m buffer around the points,
• using the buffer to clip the line into segments, then
• copy the line parallel on the left and right side using the specified distances
• then use feature vertices to points tool with mid as the point type to get the offset positions.

If there were only a few points, I would use the second method above, but unfortunately, I have hundreds.

I am familiar with ArcMap 10.1 and have a sound understanding of ArcPy and Python.

Answer 1

I think you should investigate the Make Route Event Layer (Linear Referencing) tool:

Creates a temporary feature layer using routes and route events.

When the temporary layer is used (displayed on a map, or used by another geoprocessing tool), dynamic segmentation is performed.

and in particular its optional offset_field:

The field containing values used to offset events from their underlying route. This field must be numeric.