This proceedings, ""Transportation Planning and Air Quality II"", consists of papers presented and notes taken from breakout sessions at the National Conference sponsored by the Urban Transportation Division of the American Society of Civil Engineers held in Danvers, Massachusetts on May 24-26, 1993. These papers are concerned with the improvement of air quality by controlling mobile sources of pollution. While current statistics show that most carbon monoxide and about half of the ozone precursors (volatile organic compounds and oxides of nitrogen) come from mobile sources, new laws, regulations, and procedures have been developed such that transportation planners and air quality analysts must work together in order to provide mobility while improving air quality. Thus, this proceedings brings together the ideas of individuals from the various professions dealing with transportation and air quality to allow discussion of key issues such as: the Federal Clean Air Act and transportation planning; effectiveness of transportation strategies; transportation and emissions modeling; trends in mobile source emissions modeling; air quality at intersections; and innovative approaches to transportation and emissions.