Analyses, experimental studies, and evaluations of control measures for air flow and air quality on and near highways. Volume I: experimental studies, analyses, and model development. Final report 1973-80

Experimental and theoretical investigations have been made of meteorological and air quality conditions near a broad range of complex roadway configurations. These are described, and some new insights into the interrelationships among traffic, meteorology, and configuration are discussed. The development of a new and versatile dispersion model, called ROADMAP, is also described together with an evaluation of the model's performance relative to measured atmospheric and wind tunnel pollutant concentration data. The experimental data indicates a significant effect of waste heat on near-roadway dispersion. The combined effects of traffic movement and waste heat emissions cause increases in the turbulence intensity of up to 200% across the roadway. However, there is apparently little effect on turbulence caused by changes in traffic volume or speed (for the moderate-to-heavy traffic conditions present during the tests). An aerodynamic or shelter effect is postulated to exist and to be a significant influence for grade-level roads.