Hubert Klüpfel

Evacuation Dynamics: Empirical Results, Modeling and Applications

This extensive review was written for the ``Encyclopedia of Complexity and System Science (Springer, 2008) and addresses a broad audience ranging from engineers to applied mathematicians, computer scientists and physicists. It provides an extensive overview of various aspects of pedestrian dynamics, focussing on evacuation processes. First the current status of empirical results is critically reviewed as it forms the basis for the calibration of models needed for quantitative predictions. Then various modeling approaches are discussed, focussing on cellular automata models. Finally, some specific applications to safety analysis in public buildings or public transport are presented.

Discretization effects and the influence of walking speed in cellular automata models for pedestrian dynamics

We study discretization effects in cellular automata models for pedestrian dynamics by reducing the cell size. Then a particle occupies more than one cell which leads to subtle effects in the dynamics, e.g. non-local conflict situations. Results from computer simulations of the floor field model are compared with empirical findings. Furthermore, the influence of increasing the maximal walking speed vmax is investigated by increasing the interaction range beyond nearest neighbour interactions. The extension of the model to vmax>1 turns out to be a severe challenge which can be solved in different ways. Four major variants are discussed that take into account different dynamical aspects. The variation of vmax has a strong influence on the shape of the flow–density relation. We show that walking speeds vmax>1 lead to results which are in very good agreement with empirical data.

Simulation of competitive egress behavior: comparison with aircraft evacuation data

We report new results obtained using cellular automata for pedestrian dynamics with friction. Monte-Carlo simulations of evacuation processes are compared with experimental results on competitive behavior in emergency egress from an aircraft. In the model, the recently introduced concept of a friction parameter μ is used to distinguish between competitive and cooperative movement. However, an additional influence in competition is increased walking speed. Empirical results show that a critical door width wc separates two regimes: for wwc it leads to a decrease. This result is reproduced in the simulation only if both influences, walking speed and friction, are taken into account.

Microscopic Simulation of Evacuation Processes on Passenger Ships

The analysis of evacuation processes on-board passenger ships has attracted increasing interest over the last years. Most of the approaches utilise so called flow models. Cellular automaton models, widely used for traffic simulations, on the other hand provide a more natural approach towards pedestrian dynamics. Two major difficulties are intrinsical to the problem: two-dimensional movement of pedestrians and the complexity of psychological and social influences. In this paper a simple CA-model for the description of crowd motion is presented and its implementation in a simulation software outlined. The validity of the assumptions and the scope of the applications will have to be scrutinised by comparison with empirical data from actual evacuations or drills.

Models for Crowd Movement and Egress Simulation

This paper discusses basic findings on crowd movement and their application to simulation models. This includes empirical and experimental results concerning group behavior, pedestrian motion, and emergency egress. Next to a literature review, we will present own empirical investigations on walking speed distribution and the dependency of walking speed on group size. The second part of the paper relates these findings to modelling and simulation of crowd movement. This comprises the representation of behavior, calibration and verification and the connection to many particle systems. Finally, we will present an extension of the current microscopic theory (basically underlying all the “individual” models used for real world applications). This includes route-choice behavior and links microscopic and macroscopic behavior..

Statistical Physics of Cellular Automata Models for Traffic Flow

We discuss various aspects of statistical physics in the context of traffic flow with the help of cellular automata (CA) models. CA models are, in general, idealizations of physical systems in which space and time are assumed to be discrete. In the context of vehicular traffic, CA models belong to the so-called microscopic approaches, where attention is paid explicitly to each individual vehicle and interactions among these particles are determined by the way the vehicles influence each other. Therefore, vehicular traffic, modeled as a system of interacting particles driven far from equilibrium, offers the possibility of studying various aspects of nonequilibrium systems which are of current interest in statistical physics. We give a brief overview of the Nagel-Schreckenberg (NaSch) model, considered to be one of the simplest CA models for traffic flow, and of developments based on this.

Comparison of an Evacuation Exercise in a Primary School to Simulation Results

The modeling of pedestrian movement has received growing interest over the last decades. This is due to the potential applications in facility design and especially evacuation simulation as well as the fascination of its fundamental properties. Empirical data plays a particular role with respect to both aspects. The key challenge in modeling and simulating crowd movement is to validate the model assumptions on the one hand and to verify the simulation results on the other hand. In this paper we present empirical data on an evacuation exercise in a primary school. About two hundred pupils (and their teachers) took part in the drill. Three drills were carried out. The premises are divided into two separate buildings, the larger one containing 6 classrooms with about 120 pupils. The results of the exercise are reported. Additionally, the time measured is compared to the time gained from a simulation. It took about 85 s to evacuate the whole school. It has to be noted that the result for the exercise is not a statistical one and no standard deviation can be given. The simulation estimated 160 s with parameter settings representing an average population. This deviation is mainly due to the fact that the students to not fit into this population demographics. We therefore adapted the parameters accordingly and got a result closer to the empirical one: ( ) s for the egress time (500 simulation runs), e.g., the empirical results is about

Simulation of the Evacuation of a Football Stadium Using the CA Model PedGo

Computer simulations have become an important tool for analysing egress processes and assessing evacuation concepts. Especially so called microscopic models can by now be considered state of the art. In this paper we will describe the software PedGo which is based on a 2D cellular automaton and its application to the simulation of evacuations form large and complex structures. The focus is on the practical application to full-scale scenarios. As an example, we show results for the egress from a football stadium.

OpenPedSim: A Framework for Pedestrian Flow Analysis

There exists a wide range of simulation software for the pedestrian dynamics area. Most of these software are commercial, or do not give an insight in their functionality. While this might be of little importance for some end user, it is very important for researchers to know exactly what the models are performing. This constitutes a significant advantage in the interpretation of the results. In this paper we introduce OpenPedSim (Open Pedestrian Simulation), an open source framework for performing pedestrian simulations. This framework should support researchers by the development of new models by providing a suitable environment with appropriate interfaces.