On-Road Gasoline Emissions for 2018 NEI

I am currently working with CMAQ for the years 2011–2020. For 2011–2017, I used the EQUATES data, for 2018–2020, I have transitioned to using the NEI emissions and found relevant data here:

along with the supporting documentation:

According to the TSD, the 2D emissions should include “onroad” and “nonroad” categories, without further breakdown into fuel types. However, in the data, I see separate sectors like “on-road diesel” but do not see a corresponding “on-road gasoline” category—or a total “onroad” emissions that combines both gasoline and diesel. For “nonroad,” both diesel and gasoline sectors are included.

I am unsure how to handle this discrepancy in my CMAQ inputs

I would appreciate any guidance or links to the relevant data if available.

The dataverse entry for this dataset on the s3 bucket is listed in the readme.html, and is available here:

https://dataverse.unc.edu/dataset.xhtml?persistentId=doi:10.15139/S3/4ZMKDS

This dataverse entry points to a different technical support document for 2018v2.

Perhaps this will help resolve the issue.

The onroad_gas sector was missing from the 2018gg/premerged folder due to an error in the upload script. These files are now available: AWS S3 Explorer
Thank you for reporting the issue.

For some studies like EQUATES, the onroad emissions are split into diesel and non-diesel to facilitate certain types of analyses, but conceptually they are all onroad emissions. Both types of onroad emissions should be included where available. If only the full set of onroad emissions are available, use those. Just make sure your run scripts include the appropriate emissions for the study you are using.