California Department of Transportation


Last Updated: Thursday, February 6, 2014 1:34 PM

CO Protocol

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What Is the CO Protocol?

The Transportation Project-Level Carbon Monoxide Protocol (CO Protocol), University of California Davis, December 1997, is used as part of project-level air quality analysis needed for federal conformity determinations, NEPA, and CEQA. The Protocol is the standard method for project-level CO analysis by Caltrans, replacing the 1988 Air Quality Technical Analysis Notes. Appendix B provides guidance for use of the CALINE4 modeling program in cases where the screening procedures contained in the CO Protocol are not sufficient.

Do not use Appendix A of the CO Protocol. Appendix A was developed using EMFAC 7F which is obsolete. If, when following the Protocol, quantitative screening using Appendix A is indicated, the analyst should instead perform modeling using CALINE4 as outlined in Appendix B.

Always use the current version of EMFAC for emission analysis and to support CALINE4 dispersion modeling.

Because the CO Protocol was developed and approved by EPA in the late 1990s, EMFAC 7F is mentioned in several places. That version has been superseded by more recent versions.

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