2023 Carbon Monoxide (CO) Categorical Hot-Spot Finding
Provisions for a carbon monoxide (CO) categorical hot-spot finding were included in the January 24, 2008 final conformity rule amendments at 40 CFR 93.123(a)(3) and explained in the preamble at 73 FR 4432-4434. 40 CFR 93.123(a)(3) states, "DOT, in consultation with EPA, may also choose to make a categorical hot-spot finding that §93.116(a) is met without further hot-spot analysis for any project described in paragraphs (a)(1) and (a)(2) of this section based on appropriate modeling. DOT, in consultation with EPA, may also consider the current air quality circumstances of a given CO nonattainment or maintenance area in categorical hot-spot findings for applicable FHWA or FTA projects".
Documentation and Tool
Additional Resources
- 2023 CO Categorical Hotspot Finding Webinar Recording (Passcode: g^!K9hLa) (March 2023, 31 minutes) or (PDF of slides) – This webinar recording provides an overview of FHWA's 2023 Carbon Monoxide (CO) Categorical Hotspot Finding. The webinar is for project sponsors that are interested in relying on the categorical hot-spot finding in place of doing an independent CO hot-spot analysis as part of a project-level conformity determination in CO maintenance areas outside of California.
- MOVES and CAL3QHC modeling files are available upon request from the FHWA transportation and air quality conformity team at taqc@dot.gov
- Related EPA regulations and guidance:
- Previous FHWA CO Categorical Hot-Spot Findings