Aviation Emissions and Air Quality Handbook 

• Guideline for Modeling Carbon Monoxide from Roadway Intersections 87 

This guidance provides the methodology for estimating the air quality impacts associated with vehicular traffic at intersection(s) to determine if such impacts may exceed NAAQS for CO. 

• Using MOVES in Project-Level Carbon Monoxide Analyses 88 

This guidance supersedes the emission factor sections from the 1992 CO Guidelines to reflect the use of the MOVES emissions model for project -level CO analyses. In particular, this guidance describes how to use the MOVES emissions model to estimate CO emissions from transportation projects, including roadway intersections, highways, transit projects, parking lots and intermodal terminals. This guidance can be applied when using MOVES to complete any project-level quantitative CO analysis, including hot-spot analyses for transportation conformity determinations, modeling project -level emissions for SIP development, and completing analyses pursuant to NEPA. 

## PM Project-level Analyses 

PM (i.e., PM$_{10 }$and PM$_{2.5}$) hot-spot analyses are required for projects of local air quality concern, which include certain highway and transit projects that involve significant levels of diesel vehicle traffic and any other project identified in the PM SIP as a localized air quality concern. Presently, the principal guidance document for assessing PM hot-spot analysis issued by EPA (in coordination with DOT) is the following: 

• Transportation Conformity Guidance for Quantitative Hot -spot Analyses in PM 2.5 and PM$_{10 }$Nonattainment and Maintenance Areas 89 

This guidance describes how to complete quantitative hot -spot analyses for certain highway and transit projects in PM$_{10 }$and PM$_{2.5 }$nonattainment and maintenance areas. In addition, this guidance describes transportation conformity requirements for hot -spot analyses, and provides technical guidance on estimating project emissions with EPA’s MOVES model, California’s EMFAC model, and other methods. 

## 7.2.3. Roadway Dispersion Modeling Methods 

This section provides a general overview of the process for conducting a quantitative CO and/or PM hot-spot analysis. Differences between the two modeling methods (i.e., CO and PM) are mentioned but further detailed in Appendix D , Airport Dispersion Modeling , and documented in the aforementioned EPA technical guidance documents. 

