| Most existing evacuation research is based on macro approaches which treat traffic flow as static and deterministic at aggregated levels; traffic dynamics and human behavior are overlooked. Thus, the results based on macrosimulation techniques are often unreliable. On the contrary, by simulating traffic flows on the individual-driver basis at the micro scale, agent-based modeling techniques take into account interactions and traffic dynamics, therefore presenting evacuation situations closer to reality. This study employed agent-based microsimulation techniques to model evacuation traffic flows, and investigated the relationship between evacuation sequence, evacuation response rate, transportation facilities, and the effectiveness of evacuation strategies. Three questions guided this study: (1) On general road networks, which evacuation strategy is more effective - simultaneous evacuation or staged evacuation? (2) On an actual road network, which evacuation strategy is more effective, simultaneous evacuation or staged evacuation? (3) How does evacuation performance vary under different evacuee response rates for the Florida Keys and under certain response rates, how many people will be stranded and need accommodation if an evacuation route in the Keys becomes impassible in the process of an evacuation?; Concerning evacuation sequences, we assume that "staged" evacuation strategies work more effectively than the "simultaneous" evacuation strategy if the road capacity in a risk area is limited; however, there is no evacuation strategy that works most effectively across different road network structures. In simultaneous strategy, a general warning is issued to all residents to evacuate immediately, whereas with staged evacuation strategy, residents are organized in different zones and orders to evacuate are sequentially issued to the residents in the zones within the affected area.; To answer the first question, we conducted experiments using a microscopic simulation system called Paramics on two general road networks---a simulated grid road network and a simulated ring road network. In answering the second question, we investigated the relative effectiveness of the simultaneous and staged evacuation strategies using VISSIM---a microscopic simulation system---in Galveston Island, which is extremely vulnerable to hurricane strikes. To answer the third question, we conducted simulations of hurricane evacuation of the Florida Keys using two sets of evacuation response rates. (Abstract shortened by UMI.)... |
