Field measurement of thermal environment and air pollution level inside an urban road tunnel during the evening rush hour

Abstract

Some urban road tunnels serve as the main traffic access routes for residents in the surrounding large communities. The traffic congestion is a common phenomenon during rush hours inside this kind of tunnel. In order to learn about the environmental parameters inside tunnel during the evening rush hour, a comprehensive measurement in a typical commuting tunnel is conducted. The thermal environment parameters and air pollutant distribution along the tunnel are measured simultaneously. The results show that the traffic volume, vehicle speed and air velocity inside tunnel take on the obvious temporal and spatial discrepancy. There are the average 4.58°C air temperature rise and 96μg/m3 PM2.5 concentration rise from the tunnel entrance to the tunnel exit. The PM2.5 concentration at the tunnel exit is about 2.67 times of the 24-hour average limit of Chinese standard. The rise gradients of the air temperature and PM 2.5 concentration during the evening rush hour is given out.