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This paper presents the findings of the NIST World Trade Center Investigation describing the occupant evacuation of WTC 1 and WTC 2 on September 11, 2001. The egress system, including stairwells and elevators, is described along with the evacuation procedures. The population in WTC 1 and WTC 2 on September 11, 2001 at 8:46 a.m. is enumerated and described, where the background of the population was relevant to the subsequent evacuation, including training, experience, mobility status, among others. The progress of the evacuation of both towers is described in a quasi-chronological manner. A decedent analysis explores where occupants were located when each tower was attacked. Multiple regression models were built to explore the sources of evacuation initiation delay (why people did not immediately start to leave the building), as well as stairwell evacuation time (how long the average occupant spent in the stairwells per floor). Issues identified as contributing to either slowing or aiding the evacuation process were explored. Egress simulations provided context for estimating how long WTC 1 and WTC 2 would have taken to evacuate with different populations, using three different models, and subject to different assumptions of damage to the building.

Free speeds are defined as the speeds pedestrians like to walk with when they are not hindered by other pedestrians.

Since pedestrians have different characteristics influencing their choices, free speeds will differ among individuals. These pedestrian characteristics are often not taken into account explicitly, which makes it necessary to describe free speeds as a stochastic variable with a distribution. Moreover, (free) speeds will be influenced by the characteristics of the walking infrastructure, such as grade, length, width, the type of pedestrian facility, and weather and other external conditions.

Free speeds and their distribution play an important role in many traffic flow models, but are also relevant in other applications.

The aim of this research is to derive free speed distributions for a number of traffic flow conditions. The data on which the distributions are estimated come from large-scale laboratory walking experiments. In these experiments different traffic conditions are simulated, such as unidirectional flows, opposite flows, and crossing flows.

Free speeds are highest in unidirectional flows (1.54 m/s), somewhat lower for opposite flows (1.41 m/s), and lowest for crossing flows (1.35 m/s). Reduction of this free speed is due to the interaction with other flows. For opposite flows, this interaction is reduced by lane formation (effect of self-organisation). For crossing flows however, this interaction cannot be reduced, since the flows have to interact during the crossing.

The ability to collect pedestrian flow data, without the need for subsequent post-processing and analysis to extract measurements such as density and flow rate is a goal, which up to now, has proved infeasible on a large scale for a number of reasons, such as the cost of processing the data, the ability of the people observing the scene or subsequent video tapes and the effects of variation in the lighting conditions of the area being observed. A system using low cost infrared sensors is described that can be used to track the movement of pedestrians within their field of view and the resulting data stream is then used to generate density, flow-rate and speed data and instantaneous counts every two seconds. This data is displayed and also saved in a file. In addition, the path taken by each pedestrian can also be written to file for post-processing. The processing system associated with the sensors has been designed to be scalable from the outset and we describe how this been achieved to ensure that the it can be used in a variety of application environments.

The paper investigates the evacuation of passengers from commuter trains with a focus on reduced visibility due to smoke. Fire situations in trains, where smoke can obscure the vision and have a debilitating effect on the passengers and the close geometry of the compartment allows the occupants almost no space to move away from the hazard area, require the incorporation of efficient mechanisms to assist in a rapid egress. Due to those risks two full-scale evacuation experiments were conducted in a newly released commuter train presently used by the Austrian Federal Railways, in which participants were partially subjected to non-toxic smoke. The findings of the trials have highlighted a number of issues as for example possible design revisions, improvements of the signage system and modifications of the acoustic announcement system.

Traditional lane models such as the 560 mm (22-in.) unit of exit width are examined as historical artifacts and, when studied empirically, as flawed bases for minimum stair width determination. Criticisms of this lane model were presented separately by the authors as early as about 1970 and improved bases for minimum width determination were also presented. Currently, even the improved bases for minimum stair width—based on the authors’ early work—need to be updated for stair user demographics and other factors that have changed in recent decades. Three types of crowd flow are considered; coherent flow, overtaking movement, and counterflow. All of these occurred in the evacuations of the World Trade Center in 1993 and 2001. Partly as a result of the latter incident, counterflow has recently received particular attention in some US standards and building code-change deliberations that led to a minor increase—from 1120 mm to 1422 mm (44 in. to 56 in.) in minimum, nominal exit stair width requirements for certain occupancy conditions. Completing an examination of past, current and future criteria for setting minimum stair width, the authors provide suggestions for studies that will help provide significantly improved bases for such widths in the future.

In order to deal with the event pedestrian crowd evacuation quickly in places of public assembly, to remove hidden trouble of safety in public site, the psych-physiological responses in the movement of evacuation are surveyed, using dynamic eye tracking instrument (iView X) in the related simulating scenarios, then the outputs including image files and data files are analyzed in computer. The results are useful for discussing if the location of information guideposts and boards sound reasonable and the notability of them. As a result, some principles on guiding fitting for oriental human psych-physiological reaction, and a new study method in the traffic safety field is attempted in China in the same time.

The Level of Service (LOS) is an important and necessary in evaluation on pedestrian crowd characters. It is necessary to obtain the parameters for evaluation on the facilities by analyzing the pedestrian crowd characteristics. In China, there are many crowded sites, and the authorities of government take seriously on traffic sites considering the public use, along with economic development. In crowded sites, both making analysis on pedestrian crowd traffic characteristics and to verify the LOS of the related sites, are important in practice.

In this article, in peak-time on Chinese campus, some sites may assemble pedestrian crowd, information of pedestrian crowd are surveyed, which are obtained from digital files of video cameras. By observation and measurement, the traffic environments and pedestrian traffic parameters including speed, density and volume, can be obtained. Then the relationships between parameters and the distributions of the parameters are analyzed, which is the basement of calculating the LOS of the spots and facilities and modelling. Subsequently, pedestrian crowd traffic characteristics in different sites could be supervised easily. Furthermore, pedestrian crowd behaviours and characteristics would be analyzed in details with more attention. As a result, it is used for reference on management in daily work and the same to decision-making on evacuation of pedestrian crowd in emergency.

Motorists drive through tunnels at high speeds. In consequence, they see the tunnel in a flash and have no idea how the tunnel looks like when they have to walk in the tunnel, for example, when evacuation is required. The authorities responsible for evacuation (and escape signs) are experts who fail to see the tunnel the way the general public does because they know too much. TNO studied how the nonexpert (the general public) reacts to signs when instructed to evacuate. The results showed that escape ways are ignored, and should be improved, for example, by making escape doors look like exits rather than access doors to technical rooms. One of the keys to improvement is a better signal-to-noise ratio, the signal being the evacuation signs—the noise all other visual stimuli including cars with flashing alarm lights. In a follow-up study, TNO investigated how motorists react to an unannounced disaster. Seven different groups of 50 cars each participated. They got stuck behind a “burning” heavy-goods vehicle that blocked the roadway. The study showed that motorists decided that the problem was a normal traffic jam, and so ignored the threat, waiting for the congestion to dissolve. This shows the need for an adequate “wake-up message” in order to start an evacuation.

For the design and the permit application procedure at the Linz Central Station, an evacuation simulation was carried out, which allowed questions of the individual parties involved about the evacuation of persons from the complex building to be answered. The large streams of people created by passengers changing trains called for specific regulations regarding passenger flows and evacuation scenarios.

Based on studies about human orientation behaviour, the contribution presents a synopsis of main requirements for pedestrian navigation systems, focussing on the key qualities for designing pedestrian wayfinding systems and the consideration of landmarks as spatial information in portable pedestrian navigation services (e.g. in smart phones, PDA’s, etc.). Mobile navigation services can enable pedestrians to achieve precise spatial information; yet the actual systems are not responsive to individual preferences of route characteristics.

In contrast to car drivers, pedestrians are characterized by several specific attributes: they are sensitive in terms of distance, acclivity and climatic conditions; they need salient landmarks for orientation and try to minimize the extent of mental work during the navigational process. Therefore, pedestrian navigation services have to offer a wider range of route qualities: e.g. convenience, attractiveness or safety.

To provide efficient navigational information for pedestrians, the consideration of three main route qualities is required: topography (physical quality), topology/attractiveness (psychological quality) and complexity (mental quality). Additionally, the defi nition of specific route characteristics is of great importance for the simulation of pedestrian flows to imitate route choice behaviour.

We give an outline of the most important design qualities for the development of route networks suitable for pedestrians’ needs.