4.3.3 Air Pollution
Air pollution costs refer to costs associated with motor vehicle use. Motor vehicles produce various harmful emissions that have negative effects at local and global levels. Exhaust air emissions cause damage to human health, visibility, materials, agriculture and forests [8, 9]. Mobile emissions also affect global climate as gases increase the global warming effect. We discuss this issue in the next section. Pollution costs are the product of three values:
• emission estimates, measured in kilogram (kg)/mile
• emission costs, measured in $/kg
• vehicle miles of travel (VMT), estimated by TRIMMS
These values are summed across all vehicle classes, pollutants, and impact categories to produce estimates of total pollution benefits of each TDM strategy being evaluated.