A Prioritized Routing Assistant for Flow of Traffic

Traffic management during emergency evacuation throws up a different set of challenges than a regular traffic management. We focus here on one particular challenge, namely prioritized routing. Prioritized routing may need to happen even during normal times but stands out during emergencies, since emergency vehicles, police vehicles and vehicles (such as buses) that carry a lot more people may need to have a higher priority in terms of evacuation. It is also reasonable to assume that traffic police may need to perform a centralized control of traffic since they typically have a global view of the emergency and possibly have accurate real-time updates. We therefore make the following contributions in this paper: (a) We map the prioritized routing problem to the minimum-cost maximum-flow problem, a standard problem formulation in network flow theory. (b) We then develop the Prioritized Routing Assistant for Flow of Traffic (PRAFT) that casts the prioritized routing problem which includes a notion of priority of vehicles and priority of routes into the minimum cost maximum flow problem. (c) Through a series of experiments performed using the well-known traffic simulator SUMO, we could establish that PRAFT indeed maps higher priority vehicles to better quality routes and is monotonic in the sense that decreasing priority order of vehicles maps to a decreasing route quality.