Breeze Roads Welcome to BREEZE ROADS, a complete modeling package including CAL3QHC, CAL3QHCR, and CALINE4. This modeling software package is designed to predict air quality impacts of Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Particulate Matter (PM), and other inert pollutant concentrations from moving and idling motor vehicles at or alongside roadways and roadway intersections.

This package can be used in conjunction with the MOBILE5 (or EMFAC in California) emissions model and other emission data as a tool to demonstrate compliance with:

Other applications include:

ROADS for Modeling Roadways and Intersections

Most mobile source dispersion models predict air pollution concentrations near roadways resulting from motor vehicles traveling under free-flow conditions. ROADS is an enhanced version of the CAL3QHCR, CALINE4, and CAL3QHC series of models that incorporates methods for estimating queue lengths and the contribution of emissions from idling vehicles. Because idling emissions account for a substantial portion of total emissions at an intersections, this capability represents a significant improvement over other models.

This package is especially designed to handle:

The inputs for ROADS include information commonly required by transportation models (e.g., roadway geometries, receptor locations, meteorological conditions, and vehicular emission rates). ROADS can process existing BREEZE CAL3QHCR and CALINE4 input files. Emission factors should be obtained from an accepted mobile source emission factor model such as MOBILE5.

Advanced Intersection Modeling

Additional requirements of ROADS include idling emission rates and the number of "moving lanes" approaching each intersection. ROADS includes three options for more precise specification of the operational characteristics of an intersection. These include:

For queue estimation, the model uses an approach delay equation (rather than a stopped delay) as recommended by the Transportation Research Board's 1985 Highway Capacity Manual. Based on these values, an emission source strength is calculated and then converted to a line source value so that the model can process it as a nominal free-flow link.