SIP State Implementation Plan 

SO$_{2 }$ Sulfur Dioxide 

TDS Total Dissolved Solids 

TIM Times-in-mode 

TIP Transportation Implementation Plan 

TOG Total Organic Gas 

TRB Transportation Research Board 

μg/m 3 Micrograms per cubic meter 

VALE Voluntary Airport Low Emissions 

VMT Vehicle Miles Travelled 

VOCs Volatile Organic Compounds 

