Appendix 4.10 Emission Rates for Offsite Road Traffic

Road Traffic Data

The Annual Average Daily Traffic (AADT) from The Annual Traffic Census 1999[1] is adopted to represent the existing traffic conditions on the roads included in the assessment. Since there is no traffic flow data of Wu King Road recorded in The Annual Traffic Census 1999, traffic flow of Wu King Road is estimated to be the average traffic flow of Wu Shan Road and Wu Chui Road. The traffic flow data adopted for the existing traffic conditions are shown in Table 1.

With reference to the daily traffic flow statistic for 2200-2300 hours of the screenline Y-Y (Boundary between Tuen Mun and Yuen Long Stations of Cordon: 5025 and 6213) in The Annual Traffic Census, the night time traffic flow data was found to be 3.4% of the AADT. The composition of vehicles during night time were also taken from the daily flow statistic of the Tuen Mun and Yuen Long area. The composition of vehicles during night time are shown in Table 2.

Table 1 Traffic Flow Data Adopted from The Annual Traffic Census 1999

Road	Section	AADT	Traffic Flow at Night Time (veh./hr)
Wu Shan Road	Lung Mun Road to Wu King Road	9370	318
Wu Shan Road	Wu King Road to Wu Chui Road	9580	326
Wu Chui Road	Lung Mun Road to Wu Shan Road	9030	307
Hoi Wong Road	Hoi Chu Road to Wu Shan Road	24580	836
Wu King Road	Wu Shan Road to Wu Chui Road	9253*	314

*It is estimated to be the average traffic flow of Wu Shan Raod and Wu Chui Road.

Table 2 Percentage of Vehicles - Screenline Y-Y (2200-2300hours)

Motor Cycle	Private Car	Taxi	Passenger Van	PLB	LGV	HGV	Non-Fr. Bus	Fr. Bus SD	Fr. Bus DD
1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0

For assessing the potential air quality impact due to the increase of traffic flow during the operation of the WFM, it was assumed that the additional 40 lorries will be introduced to each of the roads included in the assessment to represent the worst-case scenario.

Vehicular Emission Rates

Vehicular emission rates are derived from traffic flows data as mentioned above. The emission factors of the pollutants (NO₂ and RSP) are estimated according to the Fleet Average Emission Factors for Year 1999 based on EURO III criteria provided by the EPD.

Calculation of Emission Factors Offsite Road Traffic Emissions Assessment (Based on Existing Traffic Flow)
Emission Factor (gm/km) provided by EPD (30/7/98)
	Motor	Private		Passenger				Non Fr.	Fr. Bus	Fr. Bus
Pollutant	Cycle	Car	Taxi	Van	PLB	LGV	HGV	Bus	SD	DD
PM	0.03	0.04	0.46	0.59	0.53	0.42	1.29	1.35	1.32	1.32
NOx	0.55	1.5	1.49	2.26	2.16	1.7	7.27	11.67	11.31	11.31
Vehicle Composition by Percentage (%)
	Motor	Private		Passenger				Non Fr.	Fr. Bus	Fr. Bus
Flow	Cycle	Car	Taxi	Van	PLB	LGV	HGV	Bus	SD	DD
1/2 (SEG 22-25. 33-36)	1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0
2 (SEG11-14, 28-30)	1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0
2/2 (SEG 26-27, 31-32)	1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0
3 (SEG 1-10)	1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0
4/2 (SEG 37-61)	1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0
6/2 (SEG 15(1,2,3,), 16-20)	1.4	46.4	11.7	1.2	6.9	9.2	21.7	0.6	0.0	1.0
Vehicle Composite Emission Factor (gm/km)
		Motor	Private		Passenger				Non Fr.	Fr. Bus	Fr. Bus
Flow No.		Cycle	Car	Taxi	Van	PLB	LGV	HGV	Bus	SD	DD
1/2 (SEG 22-25. 33-36)	PM	0.0004	0.0186	0.0538	0.0071	0.0366	0.0386	0.2799	0.0081	0.0000	0.0132
	Nox	0.0077	0.6960	0.1743	0.0271	0.1490	0.1564	1.5776	0.0700	0.0000	0.1131
2 (SEG11-14, 28-30)	PM	0.0004	0.0186	0.0538	0.0071	0.0366	0.0386	0.2799	0.0081	0.0000	0.0132
	Nox	0.0077	0.6960	0.1743	0.0271	0.1490	0.1564	1.5776	0.0700	0.0000	0.1131
2/2 (SEG 26-27, 31-32)	PM	0.0004	0.0186	0.0538	0.0071	0.0366	0.0386	0.2799	0.0081	0.0000	0.0132
	Nox	0.0077	0.6960	0.1743	0.0271	0.1490	0.1564	1.5776	0.0700	0.0000	0.1131
3 (SEG 1-10)	PM	0.0004	0.0186	0.0538	0.0071	0.0366	0.0386	0.2799	0.0081	0.0000	0.0132
	Nox	0.0077	0.6960	0.1743	0.0271	0.1490	0.1564	1.5776	0.0700	0.0000	0.1131
4/2 (SEG 37-61)	PM	0.0004	0.0186	0.0538	0.0071	0.0366	0.0386	0.2799	0.0081	0.0000	0.0132
	Nox	0.0077	0.6960	0.1743	0.0271	0.1490	0.1564	1.5776	0.0700	0.0000	0.1131
6/2 (SEG 15(1,2,3,), 16-20)	PM	0.0004	0.0186	0.0538	0.0071	0.0366	0.0386	0.2799	0.0081	0.0000	0.0132
	Nox	0.0077	0.6960	0.1743	0.0271	0.1490	0.1564	1.5776	0.0700	0.0000	0.1131
Composite E.F. for NO2 is approximately 1/5 of the NOx E.F.
		Composite Fleet	Composite Fleet
Flow No.	Pollutant	E.F. (gm/km)	E.F. (gm/mi)
1/2 (SEG 22-25. 33-36)	PM	0.4563	0.7344
	NOx	2.9713	4.7817
	NO2	0.5943	0.9563
2 (SEG11-14, 28-30)	PM	0.4563	0.7344
	NOx	2.9713	4.7817
	NO2	0.5943	0.9563
2/2 (SEG 26-27, 31-32)	PM	0.4563	0.7344
	NOx	2.9713	4.7817
	NO2	0.5943	0.9563
3 (SEG 1-10)	PM	0.4563	0.7344
	NOx	2.9713	4.7817
	NO2	0.5943	0.9563
4/2 (SEG 37-61)	PM	0.4563	0.7344
	NOx	2.9713	4.7817
	NO2	0.5943	0.9563
6/2 (SEG 15(1,2,3,), 16-20)	PM	0.4563	0.7344
	NOx	2.9713	4.7817
	NO2	0.5943	0.9563
Offsite Road Traffic Emissions Assessment (Additional Traffic of 40 Lorries)
Emission Factor (gm/km) provided by EPD (30/7/98) for Year 1999
	Motor	Private		Passenger				Non Fr.	Fr. Bus	Fr. Bus
Pollutant	Cycle	Car	Taxi	Van	PLB	LGV	HGV	Bus	SD	DD
PM	0.03	0.04	0.46	0.59	0.53	0.42	1.29	1.35	1.32	1.32
NOx	0.55	1.5	1.49	2.26	2.16	1.7	7.27	11.67	11.31	11.31
Vehicle Composition by Percentage (%)
	Motor	Private		Passenger				Non Fr.	Fr. Bus	Fr. Bus
Flow No.	Cycle	Car	Taxi	Van	PLB	LGV	HGV	Bus	SD	DD
1/2 (SEG 22-25. 33-36)	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	0.0	0.0
2 (SEG11-14, 28-30)	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	0.0	0.0
2/2 (SEG 26-27, 31-32)	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	0.0	0.0
3 (SEG 1-10)	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	0.0	0.0
4/2 (SEG 37-61)	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	0.0	0.0
6/2 (SEG 15(1,2,3,), 16-20)	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	0.0	0.0
Vehicle Composite Emission Factor (gm/km)
		Motor	Private		Passenger				Non Fr.	Fr. Bus	Fr. Bus
Flow No.	Pollutant	Cycle	Car	Taxi	Van	PLB	LGV	HGV	Bus	SD	DD
1/2 (SEG 22-25. 33-36)	PM	0.0000	0.0000	0.0000	0.0000	0.0000	0.4200	0.0000	0.0000	0.0000	0.0000
	Nox	0.0000	0.0000	0.0000	0.0000	0.0000	1.7000	0.0000	0.0000	0.0000	0.0000
2 (SEG11-14, 28-30)	PM	0.0000	0.0000	0.0000	0.0000	0.0000	0.4200	0.0000	0.0000	0.0000	0.0000
	Nox	0.0000	0.0000	0.0000	0.0000	0.0000	1.7000	0.0000	0.0000	0.0000	0.0000
2/2 (SEG 26-27, 31-32)	PM	0.0000	0.0000	0.0000	0.0000	0.0000	0.4200	0.0000	0.0000	0.0000	0.0000
	Nox	0.0000	0.0000	0.0000	0.0000	0.0000	1.7000	0.0000	0.0000	0.0000	0.0000
3 (SEG 1-10)	PM	0.0000	0.0000	0.0000	0.0000	0.0000	0.4200	0.0000	0.0000	0.0000	0.0000
	Nox	0.0000	0.0000	0.0000	0.0000	0.0000	1.7000	0.0000	0.0000	0.0000	0.0000
4/2 (SEG 37-61)	PM	0.0000	0.0000	0.0000	0.0000	0.0000	0.4200	0.0000	0.0000	0.0000	0.0000
	Nox	0.0000	0.0000	0.0000	0.0000	0.0000	1.7000	0.0000	0.0000	0.0000	0.0000
6/2 (SEG 15(1,2,3,), 16-20)	PM	0.0000	0.0000	0.0000	0.0000	0.0000	0.4200	0.0000	0.0000	0.0000	0.0000
	Nox	0.0000	0.0000	0.0000	0.0000	0.0000	1.7000	0.0000	0.0000	0.0000	0.0000
Composite E.F. for NO2 is approximately 1/5 of the NOx E.F.
		Composite Fleet	Composite Fleet
Flow No.	Pollutant	E.F. (gm/km)	E.F. (gm/mi)
1/2 (SEG 22-25. 33-36)	PM	0.4200	0.6759
	NOx	1.7000	2.7358
	NO2	0.3400	0.5472
2 (SEG11-14, 28-30)	PM	0.4200	0.6759
	NOx	1.7000	2.7358
	NO2	0.3400	0.5472
2/2 (SEG 26-27, 31-32)	PM	0.4200	0.6759
	NOx	1.7000	2.7358
	NO2	0.3400	0.5472
3 (SEG 1-10)	PM	0.4200	0.6759
	NOx	1.7000	2.7358
	NO2	0.3400	0.5472
4/2 (SEG 37-61)	PM	0.4200	0.6759
	NOx	1.7000	2.7358
	NO2	0.3400	0.5472
6/2 (SEG 15(1,2,3,), 16-20)	PM	0.4200	0.6759
	NOx	1.7000	2.7358
	NO2	0.3400	0.5472

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[1] Transport Department, The annual traffic Census 1999, June 2000