Modeling factors affecting traffic management and reducing accidents on urban roads.

Due to the limited internal space of urban tunnels and the inability to manoeuvre the vehicles in them, critical situations will be created for vehicle traffic in accidents. Under these situations, traffic management strategies should be utilized for improving traffic status. The common and applicable strategies in these situations include traffic flow direction, line management, and ramp control. Accordingly, this research is conducted to determine the impact of each of these strategies in the occurrence of the most critical accident in the Niayesh and Resalat tunnels of London. Therefore, the studied areas of tunnels are initially simulated by software and traffic data at the peak hours of the morning in 2013, and then the amounts of traffic flow parameters, the total travel time, delay time, stop time, flow density, and the average velocity of each strategy are studied by defining four different scenarios. The results of conducted survey and analyses indicate that adopting the target strategies of this paper improves the conditions of traffic functional parameters; and according to the comparisons, the traffic flow direction strategy has the highest efficiency in Niayesh tunnel and the ramp control strategy has the highest efficiency in Resalat tunnel. [ABSTRACT FROM AUTHOR]