Abstract:Procedures and guidelines are provided in the Project-Level Carbon Monoxide Protocol (herein referred to as the CO Protocol), for use by agencies that sponsor transportation projects, to evaluate the potential local level carbon monoxide (CO) impacts of a project. This workbook is a supplement to the CO Protocol. Included in this workbook is an outline of the major steps to analyzing project-level CO impacts using the CO Protocol. In addition, several example applications have been constructed to illustrate use of the CO Protocol. Duplication between this workbook and the CO Protocol has been purposely kept to a minimum; the workbook is not to be considered a "stand alone" resource. The user will need to refer to the CO Protocol for definitions, contact lists, glossary terms, analysis procedures and other important material. The CO Protocol provides a structure for documenting project-level air quality analysis that is accepted by regulatory agencies. In most cases, if current analytical procedures are satisfied without modeling, the CO Protocol will not require it.