Can ArcMap create new polygon shapefiles based on the old polygon + all adjacent polygons to the original?

[MichaelWeigel]

Good morning!

For economic analysis purposes, I'm hoping to utilize an existing polygon shapefile I have of all ZIP codes in the United States to create a new shapefile with polygons for all zip codes and any directly adjacent zip code areas. The total number of polygons shouldn't at all change, they should just each be larger and overlapping. Is this possible to do within ArcMap? If not, what are some steps I could take to create something similar?

Feel free to ask for clarification if any of that doesn't make sense, and I apologize if that's a pretty basic question.

Any advice is appreciated!

-Michael

[RobertBorchert]

Why would you want them to overlap out of curiosity?  To simply make them overlap you can use the buffer analysis tool to enlarge them in mass

Are you looking to get adjacent zip code info into the polygon.

Meaning zip code 11111 is adjacent to 4 other zip codes and you want to be able to see which ones by selection 11111

To find the adjacent zip codes run the Generate Near Table Analysis tool.  It will give you a table that has your origin zip code object id as IN_FID the near object as NEAR_FID and the distance to it.

You will then just need to be a little creative to match up the FID's to the original Object ID's

[MichaelWeigel]

I guess I'm envisioning each polygon having a border of all the surrounding zip codes. So, if zip code 11111 was adjacent to the four other polygons, the new polygon would be made up of all five of those ZIP code areas. (11111 would also be part of the new polygons resulting from the other four ZIP code areas as well).

The idea would be to be able to connect the ZIP+adjacent file to other point shapefiles and do spatial joins based on the points showing up in a certain ZIP code areas as well as all those ZIPs directly adjacent to them.

Generating a list of adjacent ZIP codes in a table could prove to be helpful: I suppose I could just use a join/relate from there, although I'm not sure how that would work with doing spatial joins based on a separate point shapefile later in the process.

Appreciate the response! Hope that clarifies what I'm envisioning a bit... this seems like it'd be simple enough to do, just still learning the software and where to get queries answered. Would love to know what you (or anyone else) would advise!

-Michael