Short-Term Monitoring for Compliance with Air Quality Standards

This report contains the results of research into predicting ambient air quality exceedances at transportation project locations. It is intended to provide transportation and air quality planners and decision makers short-term monitoring procedures that can produce accurate and timely input data for predicting air quality exceedances without requiring the collection of large amounts of monitoring data. During the project, the research team developed and tested a statistical procedure to estimate probability of exceedance of the 8-hour carbon monoxide standard through the collection of a limited amount of data at the project site. This procedure is intended to reliably estimate peak emission concentrations of carbon monoxide near proposed roadway improvements while obviating the need for extensive collection of monitoring data as prerequisites inputs for dispersion models. Requiring only limited monitoring data from the project location, this approach is intended to be used as a tool in transportation planning and air quality evaluations. Thus, the procedure presented in this report may be useful in reducing the time and resources required to identify and to develop further projects that can meet the requirements of ambient air standards. The report demonstrates the feasibility of short-term monitoring procedures and identifies a number of important issues in conducting such monitoring. This report should be useful to state departments of transportation, metropolitan planning organizations, and local transportation planners as well as other practitioners concerned with planning, programming, and implementing transportation projects. The report will also be useful as an educational resource into the concepts, tools, and procedures for assessing the air quality implications of transportation projects.