'Slower is Faster' by Considering of Give-way Evacuation Behavior

Emergencies such as building fire accidents, terrorist attacks or earthquake may result in severe crowd disasters. Hence, to efficiently evacuate crowd from these life-threatening circumstances has always been of great concern to safety experts. The 'Faster is Slower' effect has been identified as every individual from crowds try to run through the exit fast, which will unavoidably exhibit competitive behavior during the evacuation. As a result, temporal clogging caused by these 'faster' evacuees will hinder the overall evacuation process. However, it is unclear that whether the 'slower' individuals who tend to give way to others will facilitate the evacuation. This paper aims to investigate the give-way behavior of evacuees by modifying the well-approved Social force model in a room evacuation scenario. We compare the evacuation performance of our developed give-way individuals with the evacuees developed in the original Social force model. The simulation results show that give-way evacuees are able to speed up the overall process of evacuation nearly 90 seconds when the exit is narrow (i.e. 0.6m). Nevertheless, as the exit width increases, the advantage of give-way behavior gradually diminishes. When the exit reaches 1m wide, longer evacuation time are required by give-way evacuees. Our work suggests that the give-way behavior of evacuees could facilitate the overall evacuation and generate the 'slower is faster' effect when the exit is narrow.