Measurements, model simulations and reduction of CO concentrations inside an urban road tunnel in Milan

Byline: M. Bedogni, S. Crapanzano, C. Lavecchia, L. Parrella A programme to improve the air quality inside the road tunnels of the Italian city of Milan has involved three steps: 1) evaluation of the air pollution levels inside some tunnels; 2) planning an air improvement project for one tunnel, supported by effectiveness evaluation; 3) implementation of this project. The characterisation of the air quality was carried out by measuring the typical traffic pollutants in relation to three different types of urban tunnels and to the traffic flows. The improvement project consisted of a ventilation system and a rearrangement of the traffic-light cycles. The effectiveness evaluation was carried out by the implementation of a multi-box model to calculate concentrations inside tunnels.