Dynamic, Stream-Balancing, Turn-Minimizing, Accessible Wayfinding for Emergency Evacuation of People Who Use a Wheelchair

People with disabilities (PWD) cannot take all the routes accessible to people without disabilities because of their disabilities, attached equipment, lower speed, and larger space requirement. This results in more challenges and slower movements for PWD during emergency evacuations in comparison with people without disabilities. This study focuses on the accessibility of egress routes to people who use a wheelchair (PWW) during an emergency evacuation, referred to as egressibility. While this research benefits from the existing literature on indoor wayfinding for PWW, it considers three additional criteria to find the most convenient route for emergency evacuation of PWW: (a) avoiding blockages due to the collapse of walls or ceilings, (b) minimizing turns, and (c) balancing the congestion by offering less-congested routes in response to new requests. The results showed that considering turn minimization as an extra factor in finding the most accessible route could prevent the evacuees from changing the elevator or taking too many turns, just to avoid a slightly less convenient, yet accessible, segment. The results also showed the efficiency of the algorithm in returning the second optimal egress route to avoid blocked segments. The pedestrian congestion minimization component of the algorithm temporarily decreases a segment’s desirability to be included in other egress routes. The experiments showed the benefit of this component in offering an alternative optimal egress route to evacuees whenever it is more convenient than the more crowded first optimal egress route.