Managing evacuation routes

This paper shows that evacuation routes, such as a building's stairwell or an urban freeway, may discharge inefficiently if left unmanaged, and that setting priority rules can speed up egress. Therefore, a simple control strategy is proposed. The strategy is decentralized and adaptive, based on readily available real-time data. The strategy is shown to be optimal in two senses: (i) it evacuates the maximum number of people at all times, and (ii) it finishes the evacuation in the least possible time. In both cases, it favors the people most at risk. The results shed light on other traffic problems.