This question follows Seeking 1990 US Commuting Zone shapefiles?

I am attempting to map US commuting zones as defined in 1990. I have successfully mapped counties from a county shapefile obtained here. After completing the following advice, I get the error message below:

In the xls, there is a column called CZ90 which I assume is the 1990 commuting zone code. Once you've joined XLS to FIPS shapefile, use the dissolve tool with the CZ90 field as the dissolve field to output a shapefile/feature class with one polygon per commuting zone.

Error Message

I used the dissolve tool and checked CZ90 as my only field; however, I get the following error message. It appears that I correctly joined the CZ90 excel file with the FIPS shapefile.

How can I successfully dissolve the counties into commuting zones?

  • What would the appropriate data type be? Short integer?
    – Matthew
    Commented Jan 28, 2019 at 1:57
  • @Luke your second suggestion worked perfectly. Thank you so much for your patience and help, Luke!
    – Matthew
    Commented Jan 28, 2019 at 2:43

1 Answer 1


It's possible the ArcGIS tool doesn't like the joined Excel fields. Try one of the below suggestions before you run the dissolve:

  1. Removing the join and using the Join Field tool which permanently adds new fields (instead of Add Join which just creates temporary virtual fields) or;
  2. Adding a short integer column to CO99_D90 called CZ90 then using the field calculator to copy the CZ90 data from the xls CZ90 into the new CZ90 then remove the temporary xls join.

Then use the new CZ90 field for the dissolve.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.