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## APPENDIX A4 - Ground Access Vehicles Emissions Inventory for Criteria Pollutants 

## A4.1 Overview 

Ground access vehicles 16 include airport passenger vehicles (e.g., private autos, taxis, limousines, shuttles, vans, buses, rental cars, etc.), vehicles transporting airport and tenant employees, airport fleet (e.g., buses, shuttles, etc.), and vehicles transporting cargo to and from the airport as well as circulating around the airport. This appendix details the methodology for computing emissions from ground access vehicles associated with airport activities. 

## A4.2 Methodology 

Ground access vehicle emissions are typically associated with three different types of airport activities: (i) vehicles traveling on- and off-airport roadways, (ii) vehicles traveling and idling within airport parking facilities; and (iii) vehicles accessing and idling at terminal curbside areas associated with passenger pickup and drop-off. 

## A4.2.1 On- and Off-Airport Roadways 

Emissions from motor vehicles traveling on- and off-airport roadways are primarily a function of vehicle-miles-travelled (VMT) within a specific roadway segment by a specific type of vehicle (e.g., passenger cars, diesel shuttles, compressed natural gas [CNG] buses, etc .). VMT are then factored against a series of pollutant emissions rates for that type of vehicle, in grams per VMT, to compute emissions. This approach is also employed for the component of parking curbside activities associated with vehicle travel (as opposed to vehicle idling). Emissions from ground access vehicles traveling on- and off-airport roadways may be estimated by applying Equation A4-1 ( Total Pollutant Emissions from Traveling Motor Vehicles ). 

Where: 

E$_{Travel }$ = total traveling motor vehicle emissions of a pollutant (i.e., CO, SO$_{2}$, PM$_{10}$, PM$_{2.5}$, NO$_{x}$, or VOC), for a given time period, expressed in pounds. 

CF = factor to convert grams to pounds (i.e., 0.0022046) 

<img src='content_image/613942.jpg'>

VMT$_{j }$= vehicle-miles-travelled on a roadway segment by vehicle type j (e.g., Honda Civic) for a given time period, expressed in miles. 

ER$_{j }$ = emissions rate of pollutant considering speed and vehicle type j, expressed in grams of pollutant per mile. 

j = vehicle type (e.g., Honda Civic). 

