There are two backup generators to ensure that the computerized traffic controls and ventilation systems in the tunnel continue to function in the event of a power failure.
Both these results can be attributed to intense traffic and poor ventilation in tunnels.
The most common sources of low-frequency noise reported were mechanical ventilation, heavy traffic, and heat pumps.
In addition to traditional mechanical ventilation tools, traffic control has been recognized as a useful approach for air quality management and congestion mitigation in tunnels.
Increased traffic emissions and reduced natural ventilation cause build up of high pollution levels in urban street canyons/intersections.
The combined noise from ventilation and road traffic caused more awakenings; worse sleep quality (−25%) and more movements reported by questionnaire.
Within our exposure chambers we were able to study actual UFP levels encountered in streets with moderate traffic or in dwellings with ventilation to busy streets.
Depending on the position in the rack, cages may differ in local environmental conditions (e.g. temperature, humidity, lighting, and disturbance) due to variation in proximity to ventilation, lights and human traffic.
This study relied on the proposition that the downwind sites we selected were, in fact, exposed to emissions from the tunnel ventilation stack during peak traffic periods.
The testing procedure is described, and the obtained experimental results and the ventilation system efficiency in normal traffic conditions are presented.
