Keywords

1 Introduction

With buildings becoming increasingly larger and more complex, the needs of the occupants in terms of accessibility and safety have also significantly increased. Buildings use is now so diversified that sometimes facilities combine the functionalities of a variety of structures such as airports, hotels, shopping center areas, public transportation terminals, apartments, and offices. Additionally, emergency situations and wayfinding generally are not the main focus for developing such facilities, and many times, such as in interventions in historical buildings, renovations and changes in buildings use, conflicting situations between information given by architecture and the available signage system may appear during an emergency.

Wayfinding difficulties may lead people to avoid places; it also can make them late for important occurrences such as business meetings or flights, which may cause loss of opportunity and money. Additionally, as settings grow in dimension and complexity, emergency evacuation emerges as a key problem, and wayfinding becomes a matter of life and death.

During an emergency into complex buildings, evacuation time is a key factor, and design effective wayfinding systems that reduce this time is a challenge for architects, designers and safety planners. According to some authors (D’Orazio et al. 2016; Kobes et al. 2010a; Vilar et al. 2014a; Vilar et al. 2013), wayfinding systems success are influenced by environmental and individual aspects such as, signs design, and location, presence of light/smoke and architectural configuration of the space, people’s attention and perception. So, effective wayfinding systems can be more complex than only using static exit signs in pre-defined points. According to Bernardini (2017), human behavior, individual’s response and Human-environment interactions seem to be underestimate by the current approaches for wayfinding systems. Thus, a large concentration of people, with different degrees of familiarity with the building, motivations, and anxieties, should be able to satisfy their needs in a network of paths leading to different destinations, even when, during an emergency, they face doubtful situations created by the incongruence between the architecture and the signage system.

In this context, this paper will present new trends in emergency wayfinding systems, mainly considering the use of technology to overcome some limitations presented by the current available systems, through a theoretical perspective.

2 Emergency Evacuation

According to Abdelgawad and Abdulhai (2009) emergency evacuation can be understood as the movement of people from a hazard area to safe destinations. This movement is made via specific routes which should be part of an evacuation plan. Thus, emergency evacuation can be defined as the process of wayfinding in stressful situations, which should be assisted by environmental information, such as definition of escape routes, signs and maps.

Considering this, three distinct analytical dimensions can be referred to the emergency evacuation behavior: the physical location of the evacuation; the existing management of the location; and the social psychological and social organizational characteristics impacting the response of persons and collectivities that participate in the evacuation (Santos and Aguirre 2004). The physical location can be understood as the total environment, from the hazard area and its configuration until the safe zone, considering the evacuation routes. The management refers to procedures, and controls deployed at evacuation, including support devices (from signs to technology-based emergency guidance).

For a successful emergency evacuation plan, these three dimensions should be aligned in order to provide congruent support to evacuees. An example of the problem with this three dimensions’ misalignment are conflicting situations created when environmental characteristics contradict safety signs information. Previous studies (e.g., Vilar et al. 2014b; Vilar et al. 2013) shown that when buildings’ architectural elements act as environmental affordances, they can interfere with occupants’ behavioral compliance with emergence egress signs, decreasing the efficiency of the egress signs and, consequently, increasing the probability of injuries.

Some authors (Kobes et al. 2010b; O’Connor 2005; Purser and Bensilum 2001), divide the evacuation process into two main categories, which comprise:

  • Pre-movement process: comprised by Cue validation/Recognition phase and Response phase;

  • Movement process.

Purser and Bensilum (2001) stated that the pre-movement process begins when an alarm is triggered or at a cue, and ends when the occupant starts his/her travel to the exit or to a safe place. The cue validation/recognition phase begins at an alarm or cue and ends with occupant’s first response. So, it is the awareness of danger by external stimuli. During this phase, occupants continue with their pre-alarm activities. The response phase is the response to danger indicators. It begins at the first response and ends when the occupant’s travel to an exit begins. It is a decision-making period during which occupants carry out a range of activities, such as investigating the situation, alerting others, fighting fire. Thus, this process depends upon hazard detection, provision of warnings, response of warnings (pre-movement phase), and pre-egress behavior (e.g., collecting belonging, seeking information, choosing an exit).

The movement process starts when the occupant’s travel to an exit begins and ends when the occupant leaves the building or find a safe place. In order to analyze this process, it is necessary to take into account the occupants flow patterns through the escape routes, and the time required for the occupants to travel to a safe place (Purser and Bensilum 2001).

Bernardini (2017) argues that, in general, evacuating people are considered as moving fluid particles by regulations about fire safety, as well as by work health and safety, and problems are solved by simply increasing number and width of evacuation paths and exits. Author also point that other widely considered approaches are related with objective measures of correlating evacuation paths width and pattern’s flow and the evacuation time in function of pedestrian’s movement speed and path length.

According O’Connor (2005), for many years evacuation time was considered the basic measure to evaluate fire protection systems. However, when human behavior is considered, many basic assumptions about occupant’s behavior with little or no basis in behavioral literature have been made by engineers, architects and designers. O’Connor (2005) gives as example the often-cited assumption that occupants’ automatically and immediately evacuate a building upon the sounding of the fire alarm system. Considering this, in last years some authors (e.g., Gamberini et al. 2003; Gamberini et al. 2015; Mantovani et al. 2001; Vilar et al. 2013) have studied the human behavior during emergency evacuation to incorporate this dimension into the prediction models, evacuation plans, and in the design of the emergency signage.

Additionally, since 2009, guidelines from European fire safety (2009) included the Available Safe Egress Time (ASET) and the Required Safe Egress Time (RSET), introducing the performance-based fire safety engineering design of buildings (ASET > RSET). So, all building occupants have to be able to evacuate the place in conditions of not-exceeded tenability criteria om the building itself. According to the guidelines from European fire safety (2009), ASET is “calculated time available between ignition of a fire and the time at which tenability criteria are exceeded in a specific space in a building” and RSET is “calculated time required between ignition to detection and the time at which the evacuation is completed”. So, ASET is mostly related with buildings features and fire characteristics, and RSET essentially considers human behavior and Human-environment interactions, including actions performed during pre-movements and movement phases (D’Orazio et al. 2016).

3 Support Systems for Indoor Emergency Wayfinding

Traditionally, static signs are the main support system for emergency evacuation used in buildings. They are a symbol-based type signs consistent with the International Organization for Standardization’s (ISO) 3864-1 (ISO 2002) standard. According to Duarte et al. (2010), efforts have been done in order to harmonize ISO and American National Standards Institute (ANSI) Z535 (2002) standards, thus text panels are also being inserted on ISO signs.

The emergency exit signs are usually made of paper, metal or plastic (Duarte et al. 2010), and must be placed where necessary (mainly on decision points) to inform people about the escape routes during an emergency. Nowadays, several types of emergency wayfinding systems can be found, such as: reflective signs, photo luminescent (PLM) signs, electrically illumined signs, interactive wayfinding systems, acoustic wayfinding systems. Mostly, these systems applications are punctual (mainly placed at intersection points and exits), however continuous systems applications are also found (D’Orazio et al. 2016).

Signage is an important issue during wayfinding process (Conroy 2001) as it optimize people’s performance in finding their way in both, everyday (Vilar et al. 2014a) and emergency situations (Mantovani et al. 2001). However, some studies have been done to investigate the efficiency of emergency exit signs, and findings suggests that static signs generally have low compliance rates, mainly when the built environment presents doubtful route-choices (i.e., exit signs pointing to corridors with lower illumination levels versus a corridor more illuminated).

Some studies have been done to examine the effect of dynamic features in signs on behavioral compliance during work-related task and an emergency egress (e.g., Nilsson 2009; Duarte 2010; Duarte et al. 2010; Duarte et al. 2014). According to Nilsson (2009), flashing lights at emergency exits, as a dynamic feature, can potentially optimize evacuation of buildings. The design aspects of flashing lights at emergency exits, namely the color of the light source, the aspect of the light and the location of the light are very important aspects to consider when designing emergency exit systems. In this way, Nilsson (2009) pointed that dynamic signage with flashing lights should have green color and lights should be placed at both sides of the exit sign. Findings of a study conducted by Duarte (2010), suggested that, for un-cued signs, dynamic presentation produced higher behavioral compliance than static ones.

According to Wogalter (2006), in a research about behavioral compliance with signs, mainly with technology support, dynamic ones can be more effective than the traditional solutions because of some features that make them more noticeable and more resistant to habituation. These features can be related with some dynamic attributes, such as availability only when necessary, use of flashing lights and sound.

Some studies have been done in order to verify the effectiveness of the emergency signage systems used into complex buildings nowadays. In researches that investigate evacuation times in buildings, Shih et al. (2000), in a VR-based study, and Xie et al. (2012), in a real world experiment, verified that in some situations people followed routes that were different from those indicated by the egress signs and, generally, regardless the presence of signs and smoke, they tried to return the direction they entered the building. The influence of the environment over behavioral compliance with exit signs was also found by Tang et al. (2009). In their study using VR, they reported that when participants were faced with seemingly contradictory information in the form of both an exit sign and an exit door, almost half of the persons choose to proceed through the door rather than follow the directions posted on the sign. The results of a previous study (i.e., Vilar et al. 2014c) revealed worrying low rates of compliance with static ISO-type exit signs (about 30%) for the first decision point, with an increment of the compliance along the route. It happens due to the fact that some architectural features can overlap the exit signs, influencing people’s wayfinding decision in a stressful situation (Vilar 2012).

Additionally, according to Bernardini et al. (2016) in situations like Architectural Heritage, fire safety regulations approaches generally suggest structural interventions to improve the occupants’ level of safety, mainly related with changes in building layout, increasing corridor’s width and number of exits, and introduction of fire-proof elements. Authors argue that this type of change represents a conflict between heritage preservation and fire safety regulations, which can affect occupant´s level of safety. An alternative could be using smart active systems, that are activated when emergency occurs.

3.1 Smart Systems for Emergency Wayfinding

Authors have suggested alternatives considering the use of technology for helping people during emergency wayfinding. They are smart active systems, based in a match between occupants’ behavior and characteristics, and environmental conditions. Smart active systems can control, for instance, doors that open and close when activated during an emergency, and technology-based signs that can be dynamic, adaptable and/or interactive. They can be available on building site, such as sensors and dynamic signs or portable equipment used by occupants of the building, such as smartphones and augmented reality devices. A review of these systems is available on Ibrahim et al. (2016). Some authors (e.g., Wogalter and Mayhorn 2006; Wogalter and Mayhorn 2005; Mayhorn and Wogalter 2003; Smith-Jackson and Wogalter 2004; Wogalter and Conzola 2002) described how this technology can produce better warnings and signs, however there are few information about their application for emergency wayfinding systems.

According to Lijding et al. (2007), smart signs are based on small computers that can be incorporated on the environment, providing users with customized context-aware guidance and messaging to support wayfinding tasks in complex buildings. Authors present a pilot study with a prototype of a smart sign which was tested on the Zilverling and Waaier Buildings of the University of Twente. For the test, 21 persons, unfamiliar with the building, were separated in two groups (control and experimental), and both were asked to perform wayfinding tasks. Control group used traditional signs and experimental group used smart signs to help during two wayfinding tasks. Results shown a significant reduction in the time needed to conclude the wayfinding tasks, as well as a significant improvement in the perception of learnability, helpfulness, efficiency and satisfaction level in comparison to the traditional signs.

Thus, smart systems can be designed as an interactive system that deliver safety information directly to users’ portable devices based on environmental information acquired by sensors. The fact that they allow information only to be delivered when needed could explain their higher effectiveness when compared to traditional emergency, corroborating McClintock et al. (2001) theory about learned irrelevance. These authors, argued that the reason why people generally do not notice emergency exit signs is because they are seldom used. According to Baker (1976), learned irrelevance is the inability to effectively respond to previously irrelevant information. McClintock et al. (McClintock et al. 2001) argued that learned irrelevance can impact human behavior in emergencies into buildings as it can cause occupants to ignore safety information (e.g. exit signs) that is available and they can see every day but never use. These authors tested an alternative design for emergency exit using blue flashing lights combined with European Back-lit emergency exit sign. The proposed design was compared with others through a questionnaire-like survey. Responses revealed that the proposed design was preferred amongst the participants and had the highest attention capturing ability.

According to attention theory (Wickens and McCarley 2008), dynamic signs such as those used in smart active systems, can be more effective to catch peoples’ attention due to their salience. Duarte et al. (2014) argued that exit signs could benefit from those dynamic features reported by Wogalter (2006) because when in emergency there is stress that might tie up attention capacity. In stressful situations, people tend to narrow their attention, thus salience could make smart signs more noticeable, and then more effective than traditional static ones. Results from a study conducted by Duarte et al. (2014) using Virtual Reality-based methodology, shown that dynamic exit signs produced better egress performance than static ones. Participants viewing dynamic signs had higher compliance rates, spent less time, covered shorter distances, and took fewer pauses in the during a virtual complex building evacuation.

According to Breznitz (1984), the effectiveness of a warning system depends significantly on its credibility. Each false alarm reduces the system effectiveness due to the fact that for the future similar alerts may receive less attention, losing credibility and creating a false alarm effect, also called by the author as “cry wolf” effect. Unfortunately, in many situations, emergency systems such as smoke detectors on hotels, fails on detecting real dangerous situation, being activated by, for instance, cigar smoke. A person who had an experience like this might perceive a future threat as less intense and might elicit weaker fear reactions. Breznitz (1984) agued that this person may reduce his/her willingness to engage a protective behavior. Smart active systems could be an alternative to decrease the false alarm effect. An example could be customized information delivered directly to occupants of a complex building during a fire. In this case, verbal message could be sent to directly to occupants alerting them that the emergency is real (or it is not an emergency simulation). Other example could be cue validation through a smart system, in which occupants could be alerted that there is a real hazard if system won´t detected protective behavior from the occupant.

The smart system presented by Gorbil and Gelenbe (2011) is an autonomous emergency support system based on opportunistic communications to support emergency evacuation. According to the authors, it was done considering low-cost human wearable mobile nodes allowing the exchange of packets at a close range of a few to some tens of meters with limited or no infrastructure. In this way, their proposed emergency support system uses opportunistic contacts (oppcomms) between wireless communication portable devices to gather information regarding the current situation and disseminate wayfinding messages to promote safe evacuation. Their solution is target for densely populated places, as node density, as stated the authors, plays an important role in the effectiveness of oppcomms. This solution was implemented and tested in a multi-agent distributed building evacuation simulator, considering two situations: a three-floor large office building, modeled based in a real building, and in a 5 km2 area of Fulham district of London. Results shown that the proposed smart system perform better than un-informed shortest path routing, and evacuation system based on static signs.

Targeting the architectural heritage issue, Bernardini et al. (2016) proposed a behavioral-based smart system that could monitor Human behaviors (mainly considering how people move) and related analyses in the evacuation process (e.g. slowing down along paths, paths blockage), suggesting the “best” evacuation path to occupants depending on their effective behaviors. According the authors, considering behavioral aspects, mainly in cases where pedestrian density effects could be more representative (e.g., narrow paths or complex layouts) could increase the system effectiveness. They tested their smart system considering an historical Italian-style theatre as case-study and compared an existent emergency wayfinding system with a smart system. The available wayfinding system was a traditional punctual one, composed by photoluminescent standard directional signs hung at the wall and placed at directional intersections. A freeware fire evacuation simulator was used to implement the new solutions (algorithm and effects, in terms of choices, on occupants). Results presented a lower evacuation time when the proposed smart system is used, with an increment for the use of secondary exits. Authors pointed out the benefits of using such system, mainly considering architectural heritage, due to the fact that with its use, no structural change is necessary, avoiding the lack of architectural characteristics of historical places.

4 Conclusions

Studies suggest that smart active systems can be more effective than traditional ones to direct people to safe places into complex buildings (e.g., Gorbil and Gelenbe 2011; Lijding et al. 2007; Vilar et al. 2014c). These smart active systems are mainly based on context, such as the weather and emergency situations, like fire or medical needs, and can also consider users’ characteristics, such as mobility limitations, health conditions. Their main goal is to optimize routes and safety communication to increase occupants’ level of safety. Smart active systems are able to inform occupants about new routes considering human behavior during the emergency wayfinding, allowing people to avoid, for instance, blocking paths. They can also be personalized delivering the information according to users’ needs.

Their effectiveness has been analyzed and evaluated mainly using building evacuation simulators (e.g., Gorbil and Gelenbe 2011; Bernardini et al. 2016) with only few prototypes being tested in real-world buildings (e.g., Lijding et al. 2007). Some authors have studied particular features of smart active systems, such as the dynamism (e.g., Duarte 2014) and availability when necessary (e.g., Vilar et al. 2014a) considering virtual reality-based methodologies, and results shown high behavioral compliance rates. However, although some patents of emergency smart systems can be found, there are still few applications of these systems into real buildings.

It is a matter of fact that the development of these systems requires a multidisciplinary approach. In this way, to ensure users safety in emergency situations, safety design should consider an interdisciplinary approach, implicating experts in several fields of knowledge, namely safety engineering, architectural design, signage design, ergonomics and human factors, psychology and technology.