Study on the Annual Reduction Rate of Vehicle Emission Factors for Carbon Monoxide: A Case Study of Urban Road Tunnels in Shenzhen, China

Table 3

Meteorological parameters in the four tunnels.

Tunnel name		Air velocity (m/s)			Temperature (°C)	Atmospheric pressure (kPa)
		Change range	Average	Standard deviation
Henglongshan Tunnel	Left bore	0∼9.2	3.85	1.15	21∼23	100.24∼101.06
	Right bore	0∼10.3	4.63	0.98	25∼30	100.79∼101.23
Cejiexian Tunnel	Left bore	0∼8.4	2.94	0.96	25∼29	100.98∼101.46
	Right bore	0∼10.1	3.66	1.46	25∼28	101.31∼101.54
Jiuweiling Tunnel	Left bore	0∼4.8	2.06	0.67	25∼27	100.27∼100.79
	Right bore	0∼7.2	3.37	0.90	25∼28	100.34∼100.88
Dameisha Tunnel	Left bore	0∼8.1	4.31	1.03	28∼37	100.55∼101.08
	Right bore	0∼11.0	2.83	1.31	29∼32	100.22∼100.65