Most of them are equipped with a GPS. The GPS coordinates from the buses are used to establish typical speeds for the buses on different parts of the bus lines. The timetables of the bus lines are stored in the time series database and are used to calculate the traffic flow of the buses. Traffic emission factors from HBEFA is used to calculate the emissions hour per hour.
Airviro is used to calculate detailed emissions from the bus fleet in Santiago.There are about 6000 buses in Santiago.