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

Table 2

Traffic survey results of the four tunnels.

Tunnel name	Daily traffic volume (pcu/d)		Peak traffic volume (pcu/h)		Remarks
	Measured value	Designed value	Measured value	Designed value
Henglongshan Tunnel	64,314	41,000	4679	5000
	71,535		4708
Cejiexian Tunnel	20,776	39,000	1886	4757
	20,780		2228
Jiuweiling Tunnel	32,753	—	1967	—	One lane of the left bore was closed
	37,641		2237
Dameisha Tunnel	32,626	44,405	2667	5400	Nonholiday period
	31,884		2756
	45,385		4119		During holidays
	43,704		3438

Note. Measured data consist of traffic volume of both left bore and right bore; designed data refer to one-way traffic for a single hole.