An official website of the United States government
Efficient emergency guidance in buildings is essential for the safe evacuation of occupants. However, occupants may be exposed to contradictory information from signage and other sources of information. This study presents a set of forced-choice VR experiments and a machine learning approach to investigate the effect of competing or conflicting guidance on exit choice in simulated scenarios. In the VR study, participants chose between two potential exits under time pressure in each trial. Attracting cues (“EXIT” signs, audio instructions) and repelling cues (“DO NOT ENTER” signs, traffic cones) were placed in front of the two exits, either individually or in combination. In total, 2,125 datapoints were recorded from 20 participants. To model exit choice, machine learning (random forest, RF) models were applied to predict and interpret the guidance on evacuation choices. The tuned-hyperparameters RF model proposed in this study showed above 75% accuracy to predict evacuation choices facing conflict cues and was superior to default RF and logistic regression models. Interestingly, repelling cues such as “DO NOT ENTER” signs had a stronger impact on exit choice than attracting cues like “EXIT” signs when people have to make choices. Overall, the study offers valuable data and insights into exit choices, revealing that negative cues are more influential than positive ones in emergencies. These findings can significantly inform the design and optimization of egress guidance systems. This bias towards negative information under pressure suggests that evacuation systems should prioritize clear and prominent negative cues to guide occupants effectively.
more »
« less
This content will become publicly available on November 1, 2026
A virtual reality experiment on visual and auditory guidance for egress in road tunnel fires
Road tunnels are enclosed spaces that most occupants only experience while driving through them. In case of fire, however, occupants potentially need to evacuate on foot from a dangerous and unfamiliar environment. Clear and accurate guidance is important for an efficient and safe evacuation from tunnels. Common cues for evacuation guidance are a signage and audio messages that attract occupants to move on appropriate egress routes and avoid unsafe routes. This paper investigates how different types of visual and auditory signals influence occupants’ exit choices in a simulated tunnel evacuation. Common guidance cues were presented to participants in a mobile Head Mounted Display, and they were asked to choose between two possible exit doors in a simulated road tunnel. Two attracting cues (‘‘EXIT’’ signs, audio instructions), and two detracting cues (‘‘DO NOT ENTER’’ signs; traffic cones placed in front of an exit) were studied in three virtual reality (VR) experiments. In each experiment, the presence and direction of the cues were manipulated, and data from 20 participants were collected. Experiment 1 explored the effects of attracting cues, Experiment 2 detracting cues, and Experiment 3 the combination of attracting and detracting cues. Across all studies, participants tended to follow the guidance provided when there was only one cue. When several competing and even contradictory cues were present, participants were most likely to rely on audio instructions, followed by traffic cones and ‘‘DO NOT ENTER’’ signs, whereas ‘‘EXIT’’ signs were often disregarded. We conclude that participants tend to follow temporary cues that could carry current information, as opposed to permanently installed signage. Some corresponding suggestions are put forward on evacuation system design and strategic planning in a tunnel fire.
more »
« less
- Award ID(s):
- 1849446
- PAR ID:
- 10652813
- Publisher / Repository:
- Springer
- Date Published:
- Journal Name:
- Fire Technology
- Volume:
- 61
- Issue:
- 6
- ISSN:
- 0015-2684
- Page Range / eLocation ID:
- 4527 to 4555
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
The present study investigated how visual characteristics of a fire influence extinguisher use. Safety guidance indicates that occupants should consider situational aspects when deciding whether to use an extinguisher, such as fire characteristics. The visual fire cues of intensity, growth rate, and smoke thickness were systematically manipulated to examine the impact on judgments to intervene with an extinguisher. Participants (N = 135) viewed simulated fire scenes as part of an experiment and judged whether they could safely attempt to use an extinguisher. The results indicated that the participants were significantly less likely to attempt extinguisher use with greater fire intensity and thicker smoke. In contrast, variations in fire growth rate did not significantly affect participant decisions. These findings indicate that perceived fire intensity and smoke density are strong factors in extinguisher use decisions, while growth rate may not meaningfully influence occupant behavior. Understanding these perceptual factors can inform fire safety education and improve guidance on when extinguisher use is appropriate, potentially enhancing residential fire response outcomes.more » « less
-
Navigation assistive technologies have been designed to support individuals with visual impairments during independent mobility by providing sensory augmentation and contextual awareness of their surroundings. Such information is habitually provided through predefned audio-haptic interaction paradigms. However, individual capabilities, preferences and behavior of people with visual impairments are heterogeneous, and may change due to experience, context and necessity. Therefore, the circumstances and modalities for providing navigation assistance need to be personalized to different users, and through time for each user. We conduct a study with 13 blind participants to explore how the desirability of messages provided during assisted navigation varies based on users' navigation preferences and expertise. The participants are guided through two different routes, one without prior knowledge and one previously studied and traversed. The guidance is provided through turn-by-turn instructions, enriched with contextual information about the environment. During navigation and follow-up interviews, we uncover that participants have diversifed needs for navigation instructions based on their abilities and preferences. Our study motivates the design of future navigation systems capable of verbosity level personalization in order to keep the users engaged in the current situational context while minimizing distractions.more » « less
-
Visualizations attempt to convey the uncertain track of an approaching hurricane. The current experiment contrasted decision characteristics that resulted from observing hurricane paths presented using cones of uncertainty versus a new form of dynamic ensemble. Participants made judgments about whether to evacuate a town at different eccentricities to the central predicted path of a storm. Results showed that dynamic ensembles have different properties to cone displays. Presentations of dynamic ensembles encouraged greater consideration of evacuation at locations further from the most probable path, but that were still at risk. However, dynamic ensembles resulted in lower evacuation rates at the center of the distribution, consistent with a probabilistic sense of the risk but nonetheless a potentially undesirable strategy. In addition, perceptions of the evacuation need with dynamic ensemble presentations were more strongly influenced by the amount of variability than with cones. The implications for use of dynamic ensembles are discussed.more » « less
-
Indoor wayfinding has remained a challenge for people with disabilities in unfamiliar environments. With some accessible indoor wayfinding systems coming to the fore recently, a major application of interest is that of emergency evacuation due to natural or man-made threats to safety. Independent emergency evacuations can be particularly challenging for persons with disabilities as there is usually a requirement to quickly gather and use alternative wayfinding information to exit the indoor space safely. This paper presents the design and evaluation of an inclusive emergency evacuation system called SafeExit4All that empowers people with disabilities (in addition to the general population) to independently find a safe exit under emergency scenarios. The Safe-Exit4All application drives an underlying accessible indoor wayfinding system with the necessary emergency evacuation system parameters customized to an individual's preferences and needs for exiting safely from a premise. Upon receiving an emergency alert, a user accesses the SafeExit4All system through an app on their smartphone that has access to real-time information about the threat, and simply follows on-screen turn-by-turn navigation instructions towards the closest safe exit. Human subject evaluations show Safe-Exit4All to be effective not just in terms of reducing evacuation time, but also in providing guidance that results in users taking deterministic, shorter, and safer paths to the exit most suitable for them.more » « less
