According to the 2004 EPA Trends Report, US on-road transportation sources emit 36% of nitrogen oxides (NOX), 63% of carbon monoxide (CO), and 29% of volatile organic compounds (VOCs). This research determines a safe roadway buffer width to protect human health from air pollutant (NOX ) exposure.; For the current Great Southwest traffic volume, it was found that 1-hour NOX standards would not be exceeded. Additional CALINE4 runs were conducted to determine how much the traffic volume could increase, and still avoid exceedances outside a 20-foot buffer width, which is a common setback distance in residential areas. It was determined that the traffic volume could increase by a factor of 15 and still protect human health from NOX impacts, using a 20-foot buffer. (Abstract shortened by UMI.)... |