This paper looks into the use of the traffic micro-simulation method to assist the tunnel ventilation system capacity design, challenging the traditional traffic assumption of uniform speed and traffic density within a tunnel where grades, on and off-ramps are often introduced. With the micro-simulation method, the vehicle behaviour in tunnel in terms of natural variability in the traffic flow and shockwave movements under super congestion can be fully analysed. Slow speeds produced in the micro-simulation can match the worst scenarios around 2 kilometres per hour, which are not effectively achieved in traditional ways. This paper starts to discuss the method of PIARC, and then introduces the traffic microsimulation software Paramics. A Paramics traffic micro-simulation model was developed for Cross City Tunnel to assist the tunnel ventilation system design. The comparison of the traffic results between PIARC and Paramics is made. (a) For the covering entry of this conference, please see ITRD abstract no. E213716.
Samenvatting