EPA's Greenbook - Listing of area in the country that are currently designated as nonattainment or maintenance for the criteria pollutants
Transportation Air Quality: Selected Facts and Figures (2016, FHWA) - This updated brochure provides an overview of recent transportation and air quality trends from across the Nation. Information regarding new federal tailpipe control standards, new air quality standards, recent travel and congestion rates by city, sources of greenhouse gas emissions, transportation policy strategies, and other useful sources of air quality-related information are provided. The resource section of this brochure provides a useful listing of relevant web sites that can link you to up-to-date transportation and air quality reports and information.
All Federal Highway Administration (FHWA) information technology systems will be unavailable, Friday, December 2, at 10:00 p.m. to Sunday, December 04, at 11:59 p.m., EDT, while work is being performed on the network. During that time, users will not be able to access any FHWA systems.