No abstract

No abstract

No abstract

No abstract

No abstract

How humans resolve non-trivial tradeoffs in their navigational choices between the social interactions (e.g., the presence and movements of others) and the physical factors (e.g., spatial distances, route visibility) when escaping from threats in crowded confined spaces? The answer to this question has major implications for the planning of evacuations and the safety of mass gatherings as well as the design of built environments. Due to the challenges of collecting behavioral data from naturally-occurring evacuation settings, laboratory-based virtual-evacuation experiments have been practiced in a number of studies. This class of experiments faces the traditional question of contextual bias and generalizability: How reliably can we infer humans’ behavior from decisions made in hypothetical settings? Here, we address these questions by making a novel link between two different forms of empirical observations. We conduct hypothetical emergency exit-choice experiments framed as simple pictures, and then mimic those hypothetical scenarios in more realistic fashions through staging mock evacuation trials with actual crowds. Econometric choice models are estimated based on the observations made in both experimental contexts. The models are contrasted with each other from a number of perspectives including their predictions as well as the sign, magnitude, statistical significance, person-to-person variations (reflecting individuals’ perception/preference differences) and the scale (reflecting context-dependent decision randomness) of their inferred parameters. Results reveal a surprising degree of resemblance between the models derived from the two contexts. Most strikingly, they produce fairly similar prediction probabilities whose differences average less than 10%. There is also unexpected consensus between the inferences derived from both experimental sources on many aspects of people’s behavior notably in terms of the perception of social interactions. Results show that we could have elicited peoples’ escape strategies with fair precision without observing them in action (i.e., simply by using only hypothetical-choice data as an inexpensive, practical and non-invasive experimental technique in this context). As a broader application, this offers promising evidence as to the potential applicability of the hypothetical-decision experiments to other decision contexts (at least for non-financial decisions) when field or real-world data is prohibitively unavailable. As a practical application, the behavioral insights inferred from our observations (reflected in the estimated parameters) can improve how accurately we predict the movement patterns of human crowds in emergency scenarios arisen in complex spaces. Fully-generic-in-parameters, our proposed models can even be directly introduced to a broad range of crowd simulation software to replicate navigation decision making of evacuees.

No abstract

Geometric design of egress and ingress configurations affects collective movement of pedestrians. Merging streams of pedestrian crowds is, in particular, one of the frequently observed features in public infrastructures and mass gatherings. However, few qualitative and quantitative studies have addressed this phenomenon in emergency situations because of the scarcity of data on human panic conditions. This paper studies the underlying geometric factors that affect dynamics and flow characteristics of merging streams in panic conditions through the use of nonhuman entities. Many experiments with panicked ants were performed in different angles and geometric characteristics. Flow rates, headway distributions, and escape speed of merging streams were studied. Results suggest that merging layouts can lead to the creation of stop-and-go phenomena and cause significant variation in the velocities of the joining paths over time. The authors also found that setups with tributary merging paths, in which a deviated stream joins a main branch, performed poorly compared with equivalent symmetrical setups. In addition, results show a dependency between traffic flow characteristics of the merged flow and the merging angle. Analyses also suggest nonexistence of a monotonic relation (or trend) between the merging angle and the merging throughput. This outcome specifically highlights the possibility of the presence of certain merging angles below and above which the overall flow performance is poorer (i.e., optimal angles). The findings provide a better understanding of the macroscopic characteristics of escaping flows in merging sections.