Using ArcGIS Pro tools to determine front of polygons in relation to street lines

Question

I am looking for help to develop a process to identify the sides and lengths of parcel polygons in relation to streets to determine the 'front' of the polygon, i.e. facing the street, so I can then determine which part of the polygon is the rear 35%. I am a planner working on detached ADU regulations in my city and while I have a decent amount of GIS knowledge and experience, this is stumping me and I feel a solution could benefit other planners who aren't GIS aces with similar projects.

I have two files available, a polygon file geodatabase for parcels, and a polyline file geodatabase for street centerlines. Both files have a field in their attribute tables that can match, the street name and street address of the parcel.

I am using ArcGIS Pro and do not currently have the knowledge or knowhow to implement any sort of PostGIS/PostgreSQL or other open source solution. I have seen a similar question posted here in 2013: Identifying FRONT LAND using ArcGIS ModelBuilder . I am really hoping to find a solution wholly within ArcGIS Pro if possible. I have not been able to implement the SQL route suggested by one of the commenters of the above link, and due to the way Feature To Line worked on a subset of test polygons I don't think it will work for many anyways, as the tool did not create each line as a unique feature but created some that while one feature contained multiple lines of the polygon (on a corner for example in the picture provided).

The dataset I am using comprises over 116,000 parcel polygons, so I'm hoping for help to develop a process that can do this for all of my polygons.

Does anyone have some ideas for how I might accomplish this?

Answer 1

First create lines that are NOT a boundary between parcels:

arcpy.PolygonToLine_management("parcels", "in_memory/OUTLINES","IDENTIFY_NEIGHBORS")
arcpy.SelectLayerByAttribute_management("OUTLINES", "NEW_SELECTION",'"LEFT_FID" >=0')
arcpy.DeleteFeatures_management("OUTLINES")

and this is actually it, because their table contains OID of parent polygon:

which you can use as a case field to summarize length and transfer it to parcels.

To prove it I split outline at vertices and drawn the lines from their mid-point to nearest road:

The only complication are going to be footpaths between parcels. So you should check if connection shares segment with what remains of them after clipping by parcels.