Hot exhaust emission factors are speed dependent functions and are expressed in g/km. It varies by fuel, vehicle segment, euro standard, pollutant, and after treatment technology. These variables are consolidated in different EF equations, given by:

ef_europe_emep_db

Format

A data.table with 6431 rows and 22 variables:

Category

Buses.

Fuel

Fuel type, classified in "D" (Diesel),"DHD" (Diesel Hybrid ~ Diesel), "DHE" (Diesel Hybrid ~ Electricity), "CNG" (Compressed Natural Gas), "BD" (Biodiesel).

Segment

character; Bus type, classified in "Ubus Midi <=15 t","Ubus Std 15 - 18 t","Ubus Artic >18 t", "Coaches Std <=18 t","Coaches Artic >18 t".

Euro

character; Euro period of vehicle, classified in "Conventional", "I", "II", "III", "IV", "V", "VI", and "EEV".

Technology

character; After treatment technology, classified in "SCR" (Selective Catalytic Reduction), "EGR" (Exhaust Gas Recirculation), and "DPF+SCR" (Diesel Particulate Filter + SCR, for Euro VI). Default is "SCR" for "IV" and "V". There are no available after treatment technology associated with euro standards "Conventional", "I", "II" and "III".

Pol

character; Pollutant, classified in "FC","CO2","CO","NOx","VOC","PM10","EC","CH4","NH3","N2O". "FC" means Fuel Consumption.

Vmin

Minimum speed for emission factor estimation, in km/h.

Vmax

Maximum speed for emission factor estimation, in km/h.

Alpha, Beta, Gamma, Delta, Epsilon, Zita, Hta, Thita

Constant parameters.

RF

Reduction Factor; In percentage (%) units.

k

Constant factor.

Details

EF = EF(Alpha, Beta, Gamma, Delta, Epsilon, Zita, Hta, RF, Speed, Function_ID, k, fcorr),

where Alpha, Beta, Gamma, Delta, Epsilon, Zeta, Eta are constant parameters; RF is the Reduction Factor, Speed in the average speed, Function_ID is the equation (function of on the year of the inventory and the pollutant); k is a constant value, and fcorr is the fuel correction factor.

The emissions factors are derived from the EMEP/EEA air pollutant emission inventory guidebook (formerly called the EMEP CORINAIR emission inventory guidebook). The document provides guidance on estimating emissions from both anthropogenic and natural emission sources.

The package presents a combination of emission factors from EMEP/EEA guidelines of 2007, 2013, 2016, and 2019, aiming to cover a greater number of pollutants and vehicle segments. The script used to process the raw EMEP/EEA databases can be found in the repository <https://github.com/ipeaGIT/gtfs2emis/blob/master/data-raw/ef_europe_emep_db.R>.

See also