Evacuation Solutions for Individuals with Functional Limitations in the Indoor Built Environment: A Scoping Review

Abstract

The built environment continues to become increasingly accessible to people with disabilities, yet there remains a lack of focus on how these individuals are evacuated in emergencies. The objective of this scoping review was to survey the academic literature to identify solutions for safely evacuating individuals with functional limitations from the indoor built environment (i.e., buildings). Journal articles and conference proceedings published in the year 2002 onwards were included. Two pairs of reviewers independently evaluated 3562 articles from ten databases and identified 99 articles. The results were categorized into six main evacuation solution types: notification, wayfinding, egress, building design, strategy, and training programs. Our findings highlight the importance of tailoring solutions to the needs of individuals with different functional limitations. Future work should focus on expanding the number of solutions available for (1) emergencies beyond fires (e.g., natural disasters); (2) unique building types that may require specialized engineering considerations; and (3) a greater variety of impairments (e.g., seeing, hearing, cognitive). We also emphasize the need for more interdisciplinary work and the importance of including rescuers and rescuees in emergency preparedness discussions. These collaborations will ensure that building designs, organizational procedures, and evacuation aids complement each other to maximize safety. To our knowledge, this is the first scoping review to identify solutions for evacuating individuals with functional limitations from buildings. These findings may help inform future recommendations for new evacuation guidelines around the world.

1. Introduction

About 16% of the global population live with a disability, and this proportion is projected to increase as we live longer [1]. These disabilities are the result of a range of impairments, including those that limit cognitive, physical, sensory functions as well as mental health. Many individuals also experience limited function transiently with pregnancy, injury or illness [2]. Impairments and other needs that affect participation in the fundamental physical and cognitive activities needed for daily life are generally termed functional limitations [3]. For instance, while an impairment may be the loss of a limb (deficiency in body structure), the associated functional limitation may be the inability to walk (activity limitation).

There has been a growing movement around the world to ensure that the built environment is accessible to meet the needs of people with functional limitations. The Americans with Disability Act was passed in 1990, and the United Nations passed the Convention on the Rights of Persons with Disabilities in 2006 [4,5]. Canada has committed to the goal set out by the United Nations to provide universal access (accessibility) to public spaces by 2030 and also passed the Accessible Canada Act in 2019 [6,7,8]. However, a critical aspect of accessibility is “egressibility”, which attempts to ensure that all occupants can be evacuated safely in the case of an emergency [6]. For instance, a review by the National Research Council of Canada found that evacuation strategies for occupants with functional limitations have been given little attention to-date [9]. Similarly, the Canadian Commission on Building and Fire Codes highlighted the need to revise strategies for evacuating people with disabilities from the built environment as a key target of future work [6].

The need for improved egressibility is more important now than ever. There is evidence from over the last 20 years from countries like Canada that (i) the proportion of people with living in the community with an impairment has increased; and (ii) the severity of these impairments has also increased [2,9]. In addition, assistive technologies that are designed to support the evacuation of individuals with functional limitations have advanced over the past decade [10,11]. Finally, it is important to note that existing guidelines for emergency evacuations tend to focus only on fire-related events. However, that has been a growing need for evacuations because of flooding, power outages or other extreme weather events due to climate change [12,13]. Evacuating people in these types of weather-related events may benefit from different approaches.

Therefore, we believe there is an urgent need to develop new guidelines for evacuating individuals with functional limitations from the built environment in emergencies. These guidelines should not only be updated based on current knowledge (e.g., existing building codes and assistive technologies), but also tailored to the type of building, functional limitation, and emergency. As part of this pressing challenge, it is important to first examine the current state and use of solutions for evacuating individuals with functional limitations. However, the only two related reviews we found that either assessed how different functional limitations can impact evacuation performance [14] or presented datasets to obtain a better understanding of egress time requirements for individuals with functional limitations [15]. We are not aware of any solution-focused scoping reviews that present available evacuation strategies that can support individuals with functional limitations during emergencies.

To address this pressing issue, this scoping review aimed to capture and evaluate research on strategies and technologies for evacuating individuals with functional limitations from the indoor built environment (i.e., buildings). This scoping review will address the following questions:

(1)

What solutions have been reported that enable safe evacuation from buildings for individuals with functional limitations?

(2)

What future work is needed to revise guidelines for evacuating individuals with functional limitations from buildings in emergencies?

Disability and Language Use

This document preferentially uses person-first language (e.g., person with a disability) rather than identity-first language (e.g., disabled person). Person-first language aims to emphasize the person first followed by information about any disability. However, we also recognize that many people in the disability community prefer identity-first language and we have switched to this usage when we refer to individuals/groups who have indicated this preference [16].

2. Methods

2.1. Review Team

Our multidisciplinary review team includes individuals with backgrounds in engineering and healthcare and expertise in prevention of injury and illness, as well as conducting scoping reviews.

2.2. Study Design

Our review followed the six stages of the Arksey and O’Malley framework, which was first developed in 2005 to better standardize the conduct of scoping reviews [17,18,19]:

(1)

Identifying the research question;

(2)

Identifying relevant articles;

(3)

Article selection;

(4)

Charting the data;

(5)

Collating, summarizing, and reporting the results;

(6)

Consulting with stakeholders.

Our protocol was also informed by the Joanna Briggs Institute Methodology for JBI Scoping Reviews [20]. Finally, our reporting was guided by the Preferred Reporting Items for Systematic Review and Meta-Analysis extension for Scoping Reviews statement [21].

2.3. Protocol

The objective, inclusion criteria, and methods for this scoping review were registered with the Open Science Framework (registration ID: osf.io/jefgy) [22] in advance and published in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols statement [23].

2.4. Eligibility Criteria

To be included in this review, articles needed to report solutions for enabling individuals with functional limitations to evacuate from buildings in an emergency. Articles were excluded if they only reported evacuation strategies for individuals without functional limitations or if they only reported evacuation strategies for elements of the built environment beyond buildings (e.g., parks or modes of transportation). The literature was limited to original, peer-reviewed journal articles and conference proceedings written in English and published from 2002 onwards. The language criterion was chosen for practical reasons based on the common languages spoken by the research team. The year 2002 was selected as a cut-off to align with the publication date of the most recent Canadian evacuation guidelines available [9].

2.5. Information Sources

Our search strategy was based on the inclusion criteria described above and was developed by combining the main concepts of this scoping review: functional limitation, evacuation, and building. The search strategy was developed for the CINAHL (via EBSCO) database and tailored for the following five additional databases: Ei Compendex and Inspec (via Engineering Village); Embase and MEDLINE (via Ovid); KCI, RSCI, SciELO CI, and the Web of Science Collection (via Web of Science); Scopus (via Elsevier). Boolean operators were used to create keyword terms by combining words found in controlled vocabularies (such as Medical Subject Headings). In cases where the equivalent of a controlled vocabulary term present in the CINAHL search string was not found in a subsequent database, the term was removed for that database only. We also included Boolean NOT operators for keywords found in irrelevant groups of articles resulting from a specific unrelated alternative meaning (e.g., the term abortion for the evacuation concept). The NOT terms were unique to each database, given that different databases use different terminologies to describe the main concepts. An academic librarian (MW) helped define the search strategy which was also iteratively refined through discussion with all authors to improve the relevance of our search results [19]. This process included hand-searching reference lists of relevant review articles and of articles in key journals (e.g., Fire Technology) to ensure the database searches did not miss key relevant articles. Our final database search was performed on 3 February 2021. See Supplementary file for details of the full search strategy.

2.6. Selection of Sources of Evidence

The final set of search results were exported and uploaded into Covidence (Covidence, Melbourne, VIC, Australia) for the removal of duplicate articles, article selection and data extraction.

A standardized set of exclusion criteria was developed and tested on 50 random articles. Four reviewers (A.A.B., B.W.R.R., W.S., and Z.G.) independently evaluated the titles and abstracts of the 50 articles using the exclusion criteria and classified each study as relevant, irrelevant, or maybe relevant. The articles classified as relevant or maybe relevant were then independently evaluated at the full-text level by the same four reviewers (articles were classified as either included or excluded). For articles classified as excluded, the primary reason for study exclusion was recorded. The exclusion criteria were refined through discussion until agreement was reached for the classification of at least 45 of the 50 articles.

Table 1. Key characteristics of included articles.

Criterion	Characteristic	Number of Articles (%)
Year of publication	2002–2005	6 (6.1%)
	2006–2009	6 (6.1%)
	2010–2013	23 (23.2%)
	2014–2017	30 (30.3%)
	2018–2020	34 (34.3%)
Article type	Journal article	59 (59.6%)
	Conference proceeding	35 (35.4%)
	Trade journal	5 (5%)
Study design	Experimental	57 (57.6%)
	Descriptive	38 (38.4%)
	Observational: cohort	0 (0%)
	Observational: cross-sectional	3 (3.0%)
	Observational: case-control	1 (1.0%)

shows our final exclusion criteria. The four reviewers used the final exclusion criteria to classify the remaining articles, where each study was classified by two reviewers. Disagreements between reviewers were resolved through adjudication by one of the other two reviewers for all stages of the classification.

2.7. Data Charting Process and Data Items

A standardized set of data extraction details was developed to extract key data from the included articles, allowing us to describe the articles and answer our research questions. Two reviewers (A.A.B. and B.W.R.R.) independently read the full text of each included study and extracted relevant details using a data extraction form. Throughout the data extraction process, the set of data extraction details was refined, and the extracted data were updated as the reviewers became familiar with the literature. The final set of details extracted from each article were:

(1)

Publication information (e.g., title and first author);

(2)

Study purpose (e.g., background and objectives);

(3)

Methodological details (e.g., design and methodology);

(4)

Evacuation information (e.g., evacuation solutions);

(5)

Outcomes (e.g., significant findings).

Disagreements between the two reviewers were again resolved through adjudication by a third team member (W.S.).

2.8. Critical Appraisal of Individual Sources of Evidence

Consistent with both the Arksey and O’Malley framework and the conduct of previous scoping reviews, no critical appraisal (i.e., systematic assessment of the validity) of the included articles was performed [17,24]. Rather, our goal was to broadly capture a preliminary understanding of all available evacuation solutions as per the goals of our review.

2.9. Synthesis of Results and Stakeholder Consultation

A narrative summary and flow diagram were created to describe our article selection process and key article descriptors were organized in tabular form. In addition, a summary of evacuation solutions is available as a supplementary file organized by specific building type, emergency type, and/or functional limitation. Finally, we identified and reported existing gaps in the literature that require future research.

To enhance this scoping review, we invited individuals with functional limitations as well as their caregivers, emergency services personnel (e.g., firefighters and paramedics), and organizations that develop evacuation technologies to contribute to this scoping review by providing feedback on it. Stakeholders provided feedback at several points throughout the review process.

3. Results

3.1. Selection of Included Articles

A total of 3562 articles were imported into Covidence, of which 11 articles were identified through hand-searching reference lists and pertinent journals. Deduplication resulted in 2945 articles being screened. Nine articles were classified as manual duplicates. After abstract and full-text screening, 99 articles were found to fulfill the eligibility criteria and were included in the review. The study selection process, from identification to inclusion, is summarized by the PRISMA flow diagram shown in Figure 1.

3.2. Characteristics of Included Articles

As seen in Table 1, the year of publication is heavily skewed toward the later years in the sample period with a median year of publication of 2015. Most articles had first authors originating in the United States (n = 37), followed by China (n = 11) and Japan (n = 10) (Table S1). Most articles were journal articles (n = 59) or conference proceedings (n = 35). The rest of the articles promoted devices or solutions targeting industry professionals and were placed in the trade journal category (n = 5). Most of the articles implemented an experimental study design (n = 57) which usually involved testing a novel emergency evacuation device or solution in a real or virtual environment. The second most common study design was descriptive (n = 38), usually composed of survey-informed articles to learn more about emergency evacuation habits among a target population. A complete summary of the characteristics of the included articles can be found in Table 1.

Out of the six solution types identified in Section 2, the most common solution types were strategy (n = 26) and egress (n = 19), followed by training programs (n = 18), building design (n = 16), wayfinding (n = 15), and notification (n = 12). While there was a total of 99 articles included in this review, four articles included solutions relevant to two or more categories and were counted multiple times. In addition, two articles focused on solutions to facilitate communication with first responders and were placed in the notification category.

Most articles targeted emergency evacuation solutions towards people with mobility impairments (n = 48), followed by older adults (n = 25), visually impaired individuals (n = 8), hearing-impaired individuals (n = 4), and cognitive/mental health-related impairments (n = 3). There were 11 articles with solutions that appealed to all populations. Notification and wayfinding solutions were largely applicable to all building types. At the same time, articles in the egress, building design, strategy, and training program categories focused more on high-rise buildings and hospitals. Most articles included solutions applicable to all emergencies (n = 69). There were 25 articles specific to fire evacuation solutions, and five articles focused on large disaster solutions. Please refer to Table S2 for a matrix characterizing the included articles based on building type and emergency type. In addition, Table S3 breaks down the articles based on building type and disability type. In this way, we aim to help readers filter through the articles based on their categories of interest.

3.2.1. Notification Solution Articles

There were 12 articles that referred to notification solutions. These articles discussed topics ranging from determining the most appropriate audio frequencies to use for audible alarms, selecting the best locations for alarm installation as well as different information delivery systems that can adapt to the needs of individuals with different impairments. Two articles also explored the use of mobile applications for individuals with hearing impairments to communicate directly with first responders in the case of an emergency [25,26].

Table 2. Articles in the solution type category “notification”.

Solution Type	Disability	Building	Study	Objective	Reported Solution	Significant Findings
Notification	All	All	Cleary, 2011 [27]	Compare the performance and survivability predictions of different commercial smoke alarm types	Dual or side-by-side photoelectric and ionization alarms	Earlier fire notification, allowing more time for evacuation
		All	Malizia et al., 2009 [28]	Develop a system to adapt emergency notifications for individuals with different abilities	System that adapts emergency notifications according to the functional limitation and device (e.g., mobile phone or personal computer)	N/A
		All	Malizia et al., 2008 [29]	To make emergency notifications accessible to all individuals	Notification solutions informed by knowledge base and expert guidelines coded as ontologies	N/A
		Historical	Lena et al., 2012 [30]	Recommend evacuation safety enhancements for historical buildings	Spoken messages and flashing lights to complement fire alarms	N/A
	Mental health related	Mental health facility	Schulz et al., 2008 [31]	Analyse the performance of a novel smoke detection system for mental health facilities	Fully recessed proprietary analogue addressable point type smoke detector combined with a small aspirating system	Equivalent performance to standard system (ceiling mounted point type smoke detectors); caters to clinical requirements and building standards
	Older adults	Residential	Cassidy et al., 2020 [32]	Investigate fatal residential fires involving older adults	Install smoke alarms in bedrooms and living rooms	Increased likelihood of safely evacuating
		Residential	Shin et al., 2019 [33]	Develop a landslide evacuation notification system for older adults	Local landslide evacuation information displayed on television in the home	N/A
	Sensory: hearing	All	Ito et al., 2013 [34]	Optimize a disaster evacuation information delivery system for individuals with hearing limitations	Optimized Information Delivery System (evacuation information sent by SMS to mobile phones)	N/A
		All	Thomas and Bruck, 2008 [35]	Compare the effectiveness of different devices for waking individuals with hearing limitations	Low frequency (520 Hz) square wave audio signal	More effective (i.e., higher likelihood of waking)
Notification: Communication with first responders	Older adults	Residential	Shintani et al., 2011 [36]	Develop an easy-to-use device for older adults to notify rescuers of the need to be evacuated	RFID-based pendant that, when pressed, notifies rescuers with location information	Reduces anxiety
	Sensory: seeing, hearing	All	Constantinou, 2018 [26]	Develop a system that allows individuals with hearing limitations to communicate with emergency services	Icon-based mobile application that records and transmits emergency details to responders	Direct access eliminates the need for intermediate individuals
	Sensory: hearing	All	Chen et al., 2016 [25]	Propose an emergency assistance system for deaf-mute and individuals and older adults	Real-time emergency reporting mobile phone application	Decreased time required to report emergencies

The term “N/A” (Not Applicable) was used to denote that there were no additional significant findings to highlight beyond the reported solution.

summarizes the main qualitative features of each included study in the notification category, including the objective and reported solution [25,26,27,28,29,30,31,32,33,34,35,36].

3.2.2. Wayfinding Solution Articles

Fifteen articles were identified that referred to wayfinding solutions. The wayfinding section was broadly defined for two categories: wayfinding devices (12 articles) and wayfinding algorithms (three articles). Most papers discussed wayfinding devices, including escape route signage, photoluminescent tiles, and instrumented walking sticks. Mobile phone wayfinding applications were also placed in the “wayfinding: device” category since they focused on location technology hardware in buildings that communicate with handheld devices, allowing for the applications to guide users to exits. In addition, all three wayfinding algorithm solutions focused on determining the most appropriate evacuation routes based on a person’s unique disability, emphasizing that the safest evacuation route is not necessarily the fastest one [37,38,39]. A complete list of wayfinding solutions can be found in

Table 3. Articles in the solution-type category “wayfinding”.

Solution Type	Disability	Building	Study	Objective	Reported Solution	Significant Findings
Wayfinding: Algorithms	Physical: mobility	All	Hashemi, 2018 [37]	Improve building accessibility for wheelchair users	Dynamic wayfinding algorithm for determining optimal (e.g., no blockages, turn-minimizing) evacuation routes (Dijkstra algorithm informed by accessibility index)	More accessible routes than traditional ones
		Hospital	Iadanza et al., 2019 [38]	Develop a navigation algorithm for evacuating hospital patients along safe routes	Wayfinding algorithm for determining the safest evacuation route in dependence of patient type (modified Dijkstra algorithm)	N/A
		Public transport terminal	Tsekourakis et al., 2012 [39]	Develop an algorithm for evacuating individuals with mobility limitations along safe routes	Decision support system that provides personalized safe routes determined by algorithm in real time	N/A
Wayfinding: Devices	All	All	Cheraghi et al., 2019 [40]	Develop a wayfinding system to allow the safe evacuation of people with disabilities	SafeExit4All Bluetooth-based wayfinding mobile phone application with real-time audio, haptic, or visual navigation feedback to closest exit	Reduces evacuation time, allows for shorter and safer paths taken
		High-rise	Carattin et al., 2016 [41]	Evaluate the effectiveness of area of refuge signage using a theory of affordances-based process	Signage should include: pictograms with well-established meanings; green colours (associated with safety); high contrast of text to background colours; low information density	Potentially more effective signage for locating and identifying areas of refuge
		Historical	Lena et al., 2012 [30]	Recommend evacuation safety enhancements for historical buildings	Photo-luminescent arrows on floors	N/A
	Cognitive: learning, developmental, memory	All	Garcia-Catala et al., 2020 [42]	Develop wayfinding technology to allow the safe evacuation of individuals with cognitive limitations	Bluetooth-based wayfinding mobile phone application with RFID for obstacle detection	N/A
	Older adults	All	Kwee-Meier et al., 2019 [43]	Compare the effectiveness of different wayfinding signage for older adults	Digital escape route signage with or without flashing elements and temporal update information	More effective (e.g., shorter decision-making time)
		All	Bernardini et al., 2017 [44]	Design wayfinding systems to help older adults evacuate from heritage buildings	Photoluminescent tiles and adhesive strips along evacuation paths	Increased evacuation speed by >20%
		Residential	DiMaria et al., 2017 [45]	Develop a robot to improve the health and safety of older adults in their homes	Robot that alerts EMS and its user of emergencies and guides its user to the nearest building exit	N/A
Wayfinding: Devices	Sensory: seeing	All	Dong et al., 2018 [46]	Develop and test efficacy of directional sound technology to allow the safe evacuation of individuals with vision impairment	Directional sound signage for wayfinding	N/A
		All	Ivanov, 2012 [47]	To present an indoor building navigation system for safe evacuation of people with vision impairments	RFID-based wayfinding mobile phone application with guidance provided by audio feedback for most optimal evacuation route	N/A
		All	Amemiya and Sugiyama, 2008 [48]	Develop a technology to allow the safe evacuation of individuals with vision impairments	Handheld wayfinding device with guidance provided by haptic feedback	N/A
	Sensory: seeing, hearing	All	Ahmetovic et al., 2020 [49]	Develop a technology to allow the safe evacuation of individuals with situational impairments	Wayfinding mobile phone application with guidance provided by audio, haptic, or visual feedback	N/A
		All	Kumar et al., 2019 [50]	Develop a Braille-assisted system for indoor navigation	Navigation system with an instrumented walking stick (smoke and water sensors), handheld Braille keypad, and obstacle avoidance functionality	Enables users to take safer evacuation routes

The term “N/A” (Not Applicable) was used to denote that there were no additional significant findings to highlight beyond the reported solution.

below [30,37,38,39,40,41,42,43,44,45,46,47,48,49,50].

3.2.3. Egress Solution Articles

We identified 19 articles in our review that referred to egress solutions. These articles broadly focused on determining the optimal rescue devices for vertical and horizontal evacuations based on overall egress times, end-user perceptions of rescue devices, and biomechanical rescuer loads. Most vertical evacuation solutions comprised stair descent rescuer devices. Articles that explored the use of occupant evacuation elevators or areas of refuge were placed in the building design section of this review (see Section 3.2.4) given that they typically require specific design requirements at the building construction stage to ensure their safe use. A complete list of egress solutions can be found in

Table 4. Articles in the solution type category “egress”.

Solution Type	Disability	Building	Study	Objective	Reported Solution	Significant Findings
	All	All	Kalikova, 2014 [69]	Develop a technology for rescuers to locate people with disabilities inside buildings	Localization of people with disabilities in buildings using RFID tags scanned at entry/exit	N/A
Egress	Physical: mobility	All	Conrad et al., 2008 [51]	Generate design ideas for rescue devices that focus on the needs of rescuers	Set of designs for rescue devices (bridgeboard, transfer rod, transfer sling, backboard wheeler, footstrap)	Ergonomic for EMS workers; novel, affordable; portable, operable; durable; cleanable
		High-rise	Hedman et al., 2019 [52]	Determine consumer opinion of commercial stair descent device design features	Devices that: (1) afford easy transfers in/out; (2) allow the user to feel secure; (3) protect them from contact with walls; (4) had a high number of straps; (5) supported users’ weights	Stronger feelings of security and safety by users
		High-rise	Zhang, 2017 [53]	Develop a device to allow individuals with mobility limitations to rapidly evacuate from high-rise buildings	Gravity-assisted vertical spiral slideway	Shorter total building evacuation time
		High-rise	Kwee-Meier et al., 2016 [54]	Select devices that increase vertical evacuation efficiency while protecting rescuer health	(1) Rescue chair with a gliding track-system; (2) fabric rescue seat with over shoulder strap	Low physical demand and high spatial flexibility
		High-rise	Chang, 2015 [55]	Report novel commercial assistive device for evacuating individuals with mobility limitations	Inflatable slide board dragged by a single rescuer (i.e., emergency escape air slide)	N/A
		High-rise	Kuligowski et al., 2015 [56]	Compare rescuer techniques when using evacuation chairs during stair descent	One rescuer in front to guide the chair and another in the back to push the chair	Less rescuers required and similar evacuation time
		High-rise	Lavender et al., 2015 [57]	Compare the physical demands of commercial sled-type evacuation devices on rescuers during stair descent	Two-rescuer devices with: (1) shorter overall length; (2) strap-integrated handles; (3) minimal wall contacts on landings; (4) high sled friction	Lower physical demand
		High-rise	Mehta et al., 2015 [58]	Compare the physical demands on rescuers of commercial track-type evacuation devices during stair descent	Devices with shorter length, longer tracks, and engagement of four wheels in stair landings	Lower physical demand
		High-rise	Lavender et al., 2014 [59]	Compare the physical demands of commercial hand-carried evacuation devices on rescuers during stair descent	Extended front handle stair chair device that allows the lead rescuer to face forward	Lower physical demand and shorter evacuation time
		High-rise	Adams and Galea, 2011 [60]	Compare the performance of commercial mobility assistive evacuation devices	Evac + Chair or Carry-Chair in horizontal evacuation and Evac + Chair in vertical evacuation	Shorter evacuation time and less rescuers required.
		High-rise	Sano et al., 2004 [61]	Investigate the possibility of using special equipment during stair descent	Evacuation chair for stair descent	N/A
Egress	Physical: mobility	Hospital	Ma et al., 2020 [62]	Learn how personnel in neonatal intensive care units handled patient transfer during wildfires	Med Sled Infant	N/A
		Hospital	Hamid A. et al., 2018 [63]	Compare the efficacy of stairs and ramp for vertical evacuation	Vertical evacuation of intensive-care hospital patients by ramp	Shorter evacuation time
		Hospital	Hunt et al., 2015 [64]	Compare the performance of common movement assistance devices for horizontal/vertical evacuation of non-ambulatory patients	Evacuation or carry chair in horizontal evacuation; evacuation chair in vertical evacuation	Shorter evacuation time
		Hospital	Iserson, 2013 [65]	To describe a novel method for vertical hospital evacuation using readily available materials	“Mattress-bedsheet” improvised stairwell descent method	Faster and more versatile than traditional methods
		Hospital	Murphy et al., 2011 [66]	Assess intensive care unit fire evacuation preparedness	Evacuation aids (e.g., under-mattress evacuation sheets, portable monitoring and life-support equipment)	N/A
		Long-term care	Doering, 2002 [67]	Develop safe emergency lift techniques for evacuating immobile long-term care residents	Two-rescuer, bed sheet-based emergency lift techniques for horizontal and vertical evacuation	Minimal physical demand on rescuers
		Residential	Lavender et al., 2020 [68]	Determine the biomechanical efficacy of commercial rescue devices on rescuers	Simple strap; binder lift; simulated inflatable seat; slip preventer without binder lift	Reduced biomechanical loads experienced by rescuers

The term “N/A” (Not Applicable) was used to denote that there were no additional significant findings to highlight beyond the reported solution.

[51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69].

3.2.4. Building Design Solution Articles

Sixteen articles proposed building design solutions that enhance emergency evacuation accessibility. These articles predominantly focused on individuals with mobility and vision impairments. Some of the proposed solutions included the addition of bidirectional evacuation routes to communal long-term care homes, using elevators for evacuation from high-rise buildings, and conceptualizing linear airport designs. Hospital-focused solutions explored the optimal size and locations of wards, designs that allow for optimal ventilation, and incorporating vertical fire compartments. Solutions targeted towards individuals with sensory impairments focused on improving the evacuation path accessibility. A full list of the identified solutions is found in

Table 5. Articles in the solution type category “building design”.

Solution Type	Disability	Building	Study	Objective	Reported Solution	Significant Findings
Building Design	All	Airport	Manley et al., 2016 [70]	Determine how airport building design affects evacuation time	(1) Linear airport design; (2) increase number and width of stairways; (3) minimize complexity of interior space	Shorter evacuation time and walking distance, as well as fewer bottlenecks
	Older adults	High-rise	Qu et al., 2019 [71]	Evaluate the evacuation safety of older adults to support building design changes	Increased ventilation	Less smoke gathered; more time for elderly to evacuate
		Long-term care	Byun, 2019 [72]	Identify challenges of evacuating older adults from welfare facilities	Two-way evacuation routes (can be achieved by adding balconies in bedrooms and locating bedrooms around a common area) that are supported by evacuation instruments	Improved evacuation routes
		Long-term care	Kang et al., 2011 [73]	Determine important factors in the evacuation of small nursing homes	Bi-directional evacuation paths	Shorter evacuation distance and time
	Physical: mobility	All	Pan et al., 2020 [74]	Investigate the effect of the geometry of bottlenecked areas on evacuation efficiency	Design bottlenecked areas with 45-degree angles	Shorter total building evacuation time
		High-rise	McConnell and Boyce, 2015 [75]	Determine the knowledge and concerns of individuals with mobility impairments regarding areas of refuge	(1) New elements in areas of refuge such as estimated waiting time, seating area, fire extinguishers, fire blankets; (2) larger refuge areas	N/A
		High-rise	Kuligowski and Bukowski, 2005 [76]	Discuss features of elevator systems that can facilitate safe operation for firefighter access and occupant egress	Elevators with: (1) real-time monitoring to ensure they remain safe to operate; (2) water-tolerant parts; (3) smoke protection; (4) enclosed area of refuge lobbies on each floor for waiting area	N/A
		Hospital	Schaffer et al., 2019 [77]	Study the evacuation efficacy of hospitals using simulations	Smaller hospital floors	Shorter total building evacuation time
		Hospital	Alonso-Gutierrez et al., 2018 [78]	Determine the effect of smoke compartment size on evacuation time	Smaller smoke compartment size	Shorter total building horizontal evacuation time
Building Design	Physical: mobility	Hospital	Tzeng and Yin, 2014 [79]	Raise awareness and propose evacuation-related hospital design changes that consider the needs of patients with restricted mobility	(1) Units for the acutely ill or mobility-limited on the ground or second floor; (2) step-free ground floor access; (3) ide enough step-free access between the ground and second floor to allow patient bed transport	Facilitates vertical evacuation; considers immobile patients in building design
		Hospital	Huang et al., 2011 [80]	Study the impact of fire due to hospital construction on respiratory care unit evacuation	Door widths in respiratory care units should be at least 2.0 m	Shorter evacuation time
		Hospital	Murphy et al., 2011 [66]	Assess intensive care unit fire evacuation preparedness	Adequate fire compartments and escape routes	N/A
		Hospital	Tseng et al., 2011 [81]	Analyse emergency response in small-scale hospitals	Areas of refuge (sub-compartments, besieged zones)	N/A
		Hospital	Passingham, 2010 [82]	Develop a fire compartment strategy for hospitals reducing the need for vertical evacuation	(1) Vertical fire compartments over multiple storeys and; (2) linking walkways between compartments	N/A
	Sensory: seeing	All	Zhang et al., 2019 [83]	Investigate the relationship between evacuation path obstacle density and evacuation time in individuals with seeing limitations	Minimize obstacle density along evacuation paths	Shorter evacuation time
		All	Sorensen and Dederichs, 2015 [84]	Provide designers with realistic data on evacuation design parameters for individuals with seeing limitations	Include handrails along evacuation paths and minimize obstacles	Increased self-orientation

The term “N/A” (Not Applicable) was used to denote that there were no additional significant findings to highlight beyond the reported solution.

[66,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84].

3.2.5. Strategy Solution Articles

There were 26 articles in our review that proposed strategies to facilitate emergency evacuation. These articles predominantly focused on logistical considerations to optimize evacuation using elevators, optimal rescuer-to-patient ratios in hospitals, the order in which patients should be evacuated, emergency preparedness strategies for older adults, and the inclusion of individuals with functional limitations in evacuation planning. Most articles in this subsection focused on individuals with mobility impairments. A full list of strategy solutions can be found in

Table 6. Articles in the solution type category “strategy”.

Solution Type	Disability	Building	Study	Objective	Reported Solution	Significant Findings
Strategy	All	All	Evans et al., 2018 [85]	Utilize the US Department of Homeland Security Ready framework for long-term care emergency preparedness	Three-step (evacuation plan and supplies as well as staff education) program for emergency preparedness	N/A
		All	Gershon et al., 2013 [86]	Characterize emergency preparedness in individuals receiving personal assistance	Involve the personal assistant in the planning and experience of an emergency	Improved emergency preparedness (e.g., having an evacuation plan)
		High-rise	Liao 2014 [107]	Explore public opinion on the use of elevators for fire escape	(1) Prioritize elevator evacuation for occupants above 20th floor; (2) Provide clear instruction by firefighters on use of elevators	N/A
		Historical	Lena et al., 2012 [30]	Recommend evacuation safety enhancements for historical buildings	Communicate evacuation protocol to people with disabilities on arrival	N/A
	Older adults	LTC	Shin-Wook and Ohnishi, 2012 [87]	Determine the fire safety of care facilities for older adults	Facility personnel assisting older adults in evacuating; increase in night-shift employees	More efficient night-time evacuations
		Residential	Coty et al., 2015 [88]	Determine factors that affect the home fire safety beliefs and practices of older adults	Smoke alarm installation program; fire escape plan; education, support network	N/A
	Physical: mobility	All	Feliciani et al., 2020 [89]	Determine the effect of exit location information provision on the evacuation behaviour of crowds containing wheelchair users	Prioritize informing wheelchair users of exit route characteristics prior to an evacuation	Shorter total building evacuation time; improves surrounding crowd dynamics for non-wheelchair users
		All	Boyce et al., 2017 [90]	Investigate the impact of instruction design on the assembly time and use of commercial stair descent devices	Reduced complexity and improved clarity of instructions; salient visual cues (colour, labelling)	Reduced device assembly time; shorter evacuation time
		All	Carattin et al., 2016 [91]	Determine the effect of type of instructions on area of refuge wayfinding	Specific instructions on reaching area of refuge with floorplan map	Quickest, most efficient, minimizes alternative escape behaviours
Strategy	Physical: mobility	High-rise	Minegishi, 2020 [92]	Investigate the feasibility of a vertical evacuation strategy that involves occupant evacuation elevators	Standard passenger elevators used by able-bodied and mobility-impaired occupants without discrimination on fire floors. Prioritize mobility-impaired occupants on non-fire floors if serviced by elevators that reach fire floor (to keep as much capacity as possible for fire floor occupants)	Alleviates congestion and allows for barrier-free evacuation
		High-rise	Liu et al., 2019 [93]	Study the feasibility of elevator-assisted evacuation of high-rise buildings	Use both stairs and elevators	Shorter total building evacuation time and travel distance to exit
		High-rise	Butler et al., 2017 [94]	Provide guidance on the design and use of evacuation elevators for individuals with mobility limitations	Consult with individuals with mobility impairments on the use of occupant evacuation elevators	Reduces anxiety and increases trust in occupant evacuation elevators
		High-rise	Koo et al., 2013 [95]	Compare novel to traditional strategies for evacuating crowds containing wheelchair users	Use of elevators that are fire and smoke protected for people with wheelchairs	Safer; shorter total building evacuation time
		High-rise	Manley and Kim, 2012 [96]	Demonstrate the effectiveness of new evacuation strategies for people with disabilities through public decision support system	(1) Assisted evacuations by healthy individuals; (2) fire-elevators for people with disabilities	(1) Better alternatives than refuge areas and elevator prohibition; (2) decreases clogging and increases total number of people evacuated
		High-rise	Sekizawa and Nakahama, 2011 [97]	Investigate the feasibility of using elevator-assisted evacuation from high-rise buildings	Limit elevator evacuation to individuals with mobility limitations	Shorter total building evacuation time
Strategy	Physical: mobility	Hospital	Boonngam and Patvichaichod, 2020 [98]	Study the fire evacuation behaviour of individuals in large hospitals	Passenger elevators that are modified to enable their safe use in fire escape	Decreased evacuation time by up to 35%
		Hospital	Zou et al., 2020 [99]	Develop a strategy for the safe and efficient evacuation of heterogenous hospital populations	Prioritize the evacuation of wheelchair users	Shorter total building evacuation time
		Hospital	Schaffer et al., 2019 [77]	Study the evacuation efficacy of hospitals using simulations	Similar proportions of rescuers and patients	Shorter total building evacuation time
		Hospital	King et al., 2016 [100]	Learn from the experiences of intensive care unit providers during hurricane evacuations	Improved communication and system-wide cooperation; include ICU providers in emergency drills	N/A
		Hospital	Murphy et al., 2011 [66]	Assess intensive care unit fire evacuation preparedness	Clear escape plan	N/A
		Hospital	Childers and Taaffe, 2010 [101]	Develop guidelines for patient evacuation prioritization	Evacuation order that switches between critical and non-critical patient groups	Shorter total building evacuation time
		Hospital	Rega et al., 2010 [102]	Propose a strategy for the emergency evacuation of hospital patients	(1) Reverse triage; (2) Stairwell task force with ambulatory patients kept in separate stairwell from other more time-intensive patients	Faster evacuation
		Hospital	Manion and Golden, 2004 [103]	Learn from a realistic vertical evacuation drill of an intensive care unit hospital	Five rescuers per patient	N/A
		Hospital + LTC	Uehara and Tomomatsu, 2003 [104]	Develop an evacuation simulation to dynamically predict the behaviour of individual rescuees	(1) Increased proportion of rescuers to rescuees; (2) H = horizontal evacuation strategy near fire zones	Shorter evacuation time
	Physical: mobility + cognitive: developmental	School	Cuesta and Gwynne, 2016 [105]	Provide evacuation performance datasets for vulnerable populations that inform future evacuation models	Utilize two/multiple separate evacuation routes	N/A
	Physical: mobility + older adults	LTC	Li et al., 2020 [106]	Develop computer simulations to model the evacuation of nursing homes	Strategic arrangement of dependent, semi-dependent and independent elderly throughout floors of nursing homes	Shorter total building evacuation time

The term “N/A” (Not Applicable) was used to denote that there were no additional significant findings to highlight beyond the reported solution.

below [30,66,77,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107].

3.2.6. Training Program Solution Articles

We identified 18 articles that focused on training program solutions. Six of these articles proposed rescuer training programs for staff, predominantly in the hospital setting. The remaining 12 articles discussed rescuee training programs to improve emergency and disaster preparedness for individuals with functional limitations. Many of the rescuee training programs were tailored to fire safety. A full list of training programs can be found in

Table 7. Articles in the solution type category “training program”.

Solution Type	Disability	Building	Study	Objective	Reported Solution	Significant Findings
Training Program: Rescuer	All	Historical	Lena et al., 2012 [30]	Recommend evacuation safety enhancements for historical buildings	(1) Communicate evacuation protocol to people with disabilities on arrival; (2) improve staff knowledge on building’s accessibility	N/A
	Physical: mobility	Hospital	LeBoeuf and Pritchett, 2020 [108]	Create simulations to practice and improve outpatient emergency management skills	Mock evacuation drills	Improves rescuer confidence, communication, teamwork, patient safety
		Hospital	Kwee-Meier et al., 2016 [54]	Compare lecture-based and virtual simulation nurse evacuation training	Virtual simulation program for nurse evacuation training	Improved evacuation preparedness in comparison to lecture-based training
		Hospital	Farra et al., 2019 [109]	Compare costs of live and virtual simulation hospital worker evacuation training	Virtual simulation training tool for hospital worker evacuation training	Less expensive
		Hospital	VanDevanter et al., 2017 [108]	Explore the nursing perspective of hospital evacuation and identify implications for disaster preparedness education	Include more hands-on exercises and low-tech options (to address power loss) in nursing disaster preparedness education	N/A
		Hospital	Kreinin et al., 2014 [111]	Review previous hospital fires to identify lessons learned	Annual evacuation drills and improved communication between hospitals and government health agencies	N/A
Training program: Rescuee	Children with complex health care needs	All	Bagwell et al., 2016 [112]	Determine the effectiveness of disaster preparedness education for families with children with special health care needs	Disaster supply starter kit with educational handouts	Increased likelihood of having a fire escape plan
	Children with complex communication needs	All	Quinn and Stuart, 2010 [113]	Improve emergency preparedness for children with complex communication needs	Emergency preparedness strategies (creating emergency plan, sharing communication dictionary with first responders, carrying communication boards)	N/A
	Mental health related	All	Welton-Mitchell et al., 2018 [114]	Develop and test a disaster preparedness intervention for individuals with mental health symptoms from previous disasters	Hybrid mental health and disaster preparedness training program	Increased disaster preparedness as a result of decreased depression and PTSD symptoms
Training program: Rescuee	Older adults	High-rise	Kloseck et al., 2014 [115]	Understand needs of apartment-dwelling older adults during emergencies	Improved public messaging for older adults on emergency preparedness	Helps clarify false belief that retirement community/management would manage all needs during emergency
		Residential	Casteel et al., 2020 [116]	Determine the effectiveness of a fire safety education program for older adults	Fire safety education program delivered by fire services personnel and homecare organizations	Increase in perceived control of fires and likelihood of having smoke alarms
		Residential	Tannous et al., 2017 [117]	Determine the effectiveness of home visit programs on emergency preparedness for older adults	Emergency preparedness home visit program with follow-up reminders (includes information on fire safety, smoke alarms, batteries, etc.)	Improved emergency preparedness (e.g., periodically checking smoke alarms)
		Residential	Twyman et al., 2014 [118]	Describe the home fire safety knowledge and risk factors of an older adult case study	Utilize primary care nurses for older adults to develop and practice home fire escape plans as well as install alarms	N/A
		Residential	Loke et al., 2012 [119]	Determine the perceptions and preparedness for disasters of older adults	Booklets and disaster preparedness training	Improves preparation for disaster (critical, since most older adults were not prepared for disaster pre-survey)
		Residential	Diekman et al., 2010 [120]	Develop a fire safety tool kit for older adults	Fire safety educational tool kit (includes, e.g., a smoke alarm assessment tool) delivered by Meals on Wheels	Increased fire safety knowledge and preparedness (e.g., having an evacuation plan)
	Physical: mobility	High-rise	McConnell and Boyce, 2015 [75]	Determine the knowledge and concerns of individuals with mobility impairments regarding areas of refuge	Increased education on refuge areas	N/A
		High-rise	Adcock and Hough, 2004 [121]	Review emergency preparedness training guidelines for individuals with mobility limitations and their employers	Set of recommended actions to improve evacuation preparedness (e.g., develop disaster plan, establish “buddy system” in workplace, ask for egress plans)	N/A
	Sensory: hearing	All	Caballero et al., 2019 [122]	Design a disaster risk management training platform for people with hearing impairments	American Sign Language-based virtual reality simulator of disaster drills and exercises	Effective; cheaper alternative to live training

The term “N/A” (Not Applicable) was used to denote that there were no additional significant findings to highlight beyond the reported solution.

below [30,54,75,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122].

4. Discussion

The purpose of this scoping review was to capture reported solutions in the literature that enable safe evacuation from buildings for individuals with functional limitations. Our results demonstrate that a successful evacuation is dependent on multiple aspects that can be related to the process of preparing for a possible evacuation as well as the execution of the evacuation itself. These aspects include ensuring that individuals with a range of impairments are notified of an emergency (notification), ensuring that these individuals can find their way to an exit (wayfinding), proposing assistive devices to help individuals to get out of the building (egress), the design of buildings (building design), employing logistical considerations to evacuate individuals in an efficient manner (strategy), and the training of rescuers and rescuees (training). The following subsections have been organized based on the six solution types identified in this review, along with a discussion of limitations and recommendations for future research.

4.1. Notification Solutions

A main theme that emerged among the notification-focused articles is the importance of tailoring the design and implementation of notification solutions to the needs of different impairments. There were two main populations that the articles focused on in this section: older adults and people with hearing impairments.

First, the results highlight the vulnerability of older adults in fire emergencies, given that they often require additional time to escape buildings and are overrepresented in fire emergency fatalities [121]. In fact, according to Diekman et al. (2010) [120], older adults are 3.7 times more likely to die in house fires than the rest of the population. These statistics are especially worrying given that the proportion of community-dwelling older adults is rising, many of whom live alone. Increasing available egress time during a fire emergency through effective notification solutions would have aided 25% of fire victims who were fatally or non-fatally injured in the US [123]. While two articles in this section of the review focused on older adults, further attention should be placed on tailored notification solutions that consider the unique needs of this population and prioritize increasing available egress time. Attention should also be placed on revising building codes and bylaws to create safer home environments for older adults, such as placing fire alarms in bedrooms and living rooms. as proposed by Cassidy et al. (2020) [32].

Second, the results show insufficient research on effective notification solutions for those with severe (60–80 dB) or profound (80+ dB) hearing loss. In the United States, 6.6 million people aged 12+ have severe to profound hearing loss in at least one ear, with three-quarters of the group being older than 60 years old [124]. As shown in Table 2, Thomas and Bruck (2008) [35] point to the ineffectiveness of strobe lights, bed shakers, and pillow shakers in waking up those with 25–70 dB hearing loss, and instead recommend using a 520 Hz square wave alarm. Ito et al. (2013) [34] proposed an information delivery system for people with profound hearing loss that displays disaster information on LED displays installed in residential and public buildings, though some components of this technology are now outdated. There was also one study that adapted notification solutions based on a person’s impairment, technological device, and emergency, though the solution would require a user to have a mobile phone or other device on hand at all times and may not be suitable for imminent emergencies that require immediate evacuation [28]. As a result, further research into effective non-audible notification systems that are tailored to those with severe or profound hearing loss is needed. Other impairments that may require tailored notification solutions can also be explored, such as people with autism spectrum disorder, anxiety, or cognitive impairments.

Another theme that emerged among the results is the need to often tailor notification solutions to the building type. This was demonstrated by Schulz et al. (2008) [31], who designed and evaluated an aspirated recessed point-type smoke detector for mental health hospitals that complies with both building standards and clinical patient safety requirements. This building design-tailored approach to notification solutions was otherwise largely absent in our review and could present as a unique area for future research. Some other building types that may require specialized engineering considerations and should be further explored include correctional facilities and indoor stadiums.

4.2. Wayfinding Solutions

The results demonstrate that, in contrast to outdoor wayfinding, accessible indoor wayfinding systems for individuals with functional limitations continue to be an emerging area of research. This is in part due to the increased challenges with (1) selecting location technologies that can effectively be used indoors, and (2) accommodating the common needs and behaviours of individuals with functional limitations when evacuating from an indoor environment, such as minimizing turns, navigating obstacles, and remaining close to walls for spatial orientation.

First, in contrast with outdoor wayfinding, global navigation satellite systems (GNSS) such as GPS cannot be used in an indoor environment with accuracy due to interference from the structural materials of buildings. As a result, all the articles in our review that proposed wayfinding apps employed alternative location technologies, including Bluetooth low energy (BLE), millimetre wave, and passive RFID tags [40,42,47,49]. Garcia-Catala et al. (2020) [42] provided an in-depth analysis and comparison of the different location technologies that can be used indoors, noting that BLE solutions with beacons installed throughout a building address both accuracy and affordability domains. Indeed, three of the four wayfinding apps included in our study employed BLE technology as part of their solution [40,42,49]. Furthermore, the use of computer vision may be limited in the case of a fire emergency with thick smoke [125]. Also, active RFID technologies can be effective; however, their costs are high when used on the scale of a building-level solution [42]. According to Seco-Granados et al. (2012) [126], there has been interest in using digital signal processing to minimize the signal degradation associated with GPS in an indoor environment, though this strategy was not used in any articles included in our review. Almost all the wayfinding articles included in our review that proposed a device or algorithm utilized a modified form of the Dijkstra shortest path algorithm, which calculates the shortest path to an exit among all sensors or “nodes” deemed active and safe [37,38,40,42]. Nodes were deemed safe or unsafe based on a variety of sensors placed at each node or by employing a building expert familiar with the emergency. It should be noted that, of the four wayfinding apps and three algorithm articles included in our review, only one tested their proposed solution in a simulation with human participants [40]. Hashemi (2018) [37] proposed that it may be beneficial for everyone to use a wayfinding app during an emergency regardless of disability to manage crowd dynamics and aid those with situational impairments or limitations imposed by the emergency at hand. Furthermore, it has been suggested that first responders can benefit from wayfinding apps to identify locations with inactive nodes in which occupants may need help or to avoid congested areas that can impede rescue time [37]. As a result, further research needs to be performed in a real-world environment, accounting for the unique behaviours among evacuees with functional limitations in a stressful evacuation setting, as well as their interaction with crowds and first responders. Nevertheless, there may be increased challenges and considerations when completing such tests, including ethics and participant recruitment.

The second challenge of indoor wayfinding systems is accounting for the increased obstacles and turns present in indoor environments and subsequently tailoring wayfinding solutions to the unique needs and behaviours of individuals with functional limitations as they evacuate from such environments. For instance, individuals with mobility impairments often require routes that traverse wide hallways with the least number of obstacles and turns [37]. Individuals with vision impairments often walk close to walls and handrails for spatial orientation, especially in unfamiliar environments [47]. As such, the most common features of wayfinding apps in our review were obstacle avoidance, turn minimization, route recalculation, congestion management, and route personalization according to disability. Accessible indoor wayfinding algorithms, apps, and other devices are of great importance, as many individuals with functional limitations tend to exit the way they entered due to fear that other routes may not be accessible (Lena et al., 2012) [30]. This could be concerning if the route chosen is unsafe in the event of an emergency. It is also worth noting that wayfinding technologies should not impede how people with functional limitations organically interact with their support devices or built environment. For instance, it has been suggested that integrating electronics in a white cane may impact the sensitivity of those with vision impairments due to a change in the weight of the cane [47]. Furthermore, wayfinding cues in the form of audio feedback may not be suitable since they conflict with environmental audio information that individuals with vision impairments often rely on and use as their primary channel of orientation [48]. Instead, haptic feedback may provide intuitive guidance without such interference [48]. As a result, indoor navigation systems should employ a user-centred approach, taking into consideration how individuals with functional limitations interact with buildings and respond to emergencies. It should be noted that balancing technology with user comfort and ease of use often involves increased challenges and trade-offs, such as increased complexity and customization of system design.

While most articles focused on those with sensory or mobility limitations, one study considered individuals with cognitive impairments [42]. Given the heterogeneity of this population, further research was encouraged to validate wayfinding solutions that promote their autonomy and address their unique challenges, such as information processing, problem-solving, and attention in the face of stressful situations. It should be noted that Bukvic et al. (2021) [14] identified a lack of studies that connect the impact of cognitive impairments on evacuation performance in their scoping review, and may be a necessary step before identifying suitable evacuation solutions for the population. In terms of building types, there was good representation among the wayfinding solutions with some articles focusing on unique building types such as historical buildings and public transport terminals [30,39,44]. Subway egress is especially unique given that evacuees usually need to climb stairs to reach the ground level and that subway stations are often crowded and vulnerable to bottlenecks, even without emergencies [39]. The results also show a need to make historical buildings more accessible [30]. On that front, wayfinding tiles and arrows made of photoluminescent materials may be a robust and cost-effective way of retrofitting historical buildings with a wayfinding aid that preserves important structural elements of the building [30,44]. Directional sound signage is particularly beneficial in smoke-filled environments but is limited by interference when placed at adjacent exits in close proximity [46]. There should be continued attention to wayfinding solutions in unique and complex building types, many of which potentially pose increased evacuation difficulties for those with functional limitations.

4.3. Egress Solutions

Our results demonstrate that there has been significant attention in the literature on horizontal and vertical evacuation solutions for high-rise buildings and hospitals. Nearly all of the egress articles that focused on high-rise buildings tested their evacuation devices in a simulated or real-world environment. In contrast, only three of the seven hospital-focused articles tested their egress solutions [63,64,67]. Devices most suitable for vertical evacuation often differed from those most suitable for horizontal evacuation due to the inherent differences in the evacuation paths, the unique challenges of stairwells, and differences in the number of rescuers needed based on each type of evacuation [54]. Whereas horizontal evacuation refers to egress to a place of safety or an adjacent fire compartment on the same floor of a building, vertical evacuation involves descending or ascending to an exit and often requires the use of stairs.

An important challenge to the use of stair descent devices is the need to increase movement and efficiency through the landing areas of stairwells, given that this is where stair descent devices were the slowest throughout the evacuation route [57,64]. Slow-moving stair descent devices may increase congestion in landing areas, which are already vulnerable to bottlenecks [127]. As such, Lavender et al. (2015) [57] and Mehta et al. (2015) [58] proposed that sled-type and track-type evacuation devices adopt shorter overall lengths to improve efficiency and reduce wall contact on landings. Attention should also be placed on developing devices that reduce the coefficient of friction on landings while still providing enough friction to ease descent on stairs [57,64]. Hunt et al. (2015) [64] further noted that the physical presence of the stair descent device itself can impact the flow of other evacuees or first responders using the stairwell at the same time. Only two articles in our review considered the impact of stair descent devices on the flow dynamics of other evacuees using the same evacuation route simultaneously [59,64].

An inconsistency observed among the study methodologies was whether the rescuers recruited in the simulation trials were trained in the operation of rescue devices. This led to discrepancies in average egress times across different articles [56,57]. Lavender et al. (2015) [57] noted that, given the infrequency of building-wide evacuations requiring the use of rescue devices, a certain level of inexperience among rescuers is to be expected in a real-world scenario. Iserson (2013) [65] adds that few fire departments practice evacuating multiple non-ambulatory patients simultaneously on a routine basis. As such, recruiting untrained rescuers may represent the most realistic test data for emergency evacuation. The prevalence of rescuers not adept in the operation of rescue devices also highlights the importance of having cues within the design of devices that prompt their intended use, such as handles integrated into straps, which can facilitate their correct and efficient operation [57]. Further nuances, such as rescue device preparation time, psychological and physiological stresses present in an emergency setting, and the effect of poorly lit stairwells were not present among the articles included in our review when determining optimal rescue devices, prompting further research in this area.

Many articles focused their research on rescuers, either by gathering their impressions on the use of different rescue devices or by exploring devices that minimize rescuer biomechanical loads. While understanding the needs of rescuers is important, there was only one study included in our review that exclusively focused on the perspectives of individuals with functional limitations when using different rescue devices [52]. Kwee-Meier et al. (2016) [54] explored both the physical demands of different devices on rescuers and the rescuees’ perception of the devices. Conrad et al. (2008) [51] noted that clear end-user acceptance data and feedback could increase future adoption rates among rescuers, such as ensuring that rescue devices are easy to use and ready with little setup time. Similarly, Hedman et al. (2019) [52] emphasized the importance of including the participation of individuals with functional limitations in emergency evacuation planning. The study authors further stressed that those with functional limitations should try out various devices as part of the emergency planning process, noting that many study participants modified their perceptions of different evacuation devices after participating in the trials (Hedman et al., 2019) [52]. There may also be a benefit to further distinguishing the needs of individuals with mobility impairments from those with upper extremity versus lower extremity limitations, as proposed by Bukvic et al. (2021) [14] in their recent scoping review.

It is important to note that, in practice, many healthcare facilities such as small-scale hospitals either lack funding, the necessary staff resources, or the expertise to adequately purchase and conduct a mass evacuation of non-ambulatory patients using vertical evacuation devices [65,81]. Many hospitals are further constrained during night shifts when fewer staff are available in an emergency. For instance, in Hunt et al.’s (2015) [64] ward evacuation simulation study, the authors found that there were insufficient night shift staff available to evacuate 28 patients with reduced mobility down 11 floors in a reasonable amount of time, irrespective of the vertical evacuation device used. As a result, further research into cost-effective evacuation devices that fit the preferences of rescuers and rescuees alike is needed. While improvised and cost-effective evacuation devices such as bedsheet-based solutions have been reported in our review, it is important that they do not sacrifice rescuer physical demands or rescuee safety [65,66,67]. A low-cost modification to the improvised bedsheet solution that decreases biomechanical loads for rescuers is the transfer rod, which allows the bedsheet to be wrapped around it [51]. Other strategies that may appeal to small-scale hospitals include exploring how emergency evacuation elevators can reduce staffing requirements for egress as well as building design considerations that can limit the need for vertical evacuation. Emergency evacuation elevators and building design considerations are further discussed in Section 4.4.

4.4. Building Design Considerations

The tragic events of 9/11 resulted in many changes concerning emergency evacuation. One such change is a shift from a “stay put” to an “everyone out” approach, in which emergency plans are expected to provide a means for all occupants, including individuals with functional limitations, to evacuate from buildings if safe to do so [128]. As such, it is important to ensure that buildings are designed in an inclusive manner to facilitate the ability of individuals with functional limitations to independently or dependently evacuate from buildings.

Individuals with visual impairments are a population that can be greatly impacted by the design of buildings, given that they need to be oriented within their environments during evacuation. One theme that emerged in our scoping review was the need to minimize obstacles along evacuation routes. In this context, Sorensen and Dederichs (2015) [84] pointed to the importance of egress paths without obstacles. At the same time, Zhang et al. (2019) [83] recommended that when paths cannot be made obstacle-free, keeping the cumulative obstacle density (defined as the ratio of the total floor area taken up by all obstacles in an evacuation zone to the total floor area in the zone) below 0.071 was recommended. This obstacle density range represents a stable condition in which the impact on travel time along an egress route for individuals with vision impairments is less than when the obstacle density exceeds 0.071. This finding may be particularly valuable for building types with egress paths that cannot be completely clear of obstacles, such as hospitals. However, it is important to note that this study only investigated the use of chairs (50 cm × 50 cm × 100 cm) as obstacles and it remains unclear how larger obstacles might impact the travel time. As such, further validation is required with a larger number of participants, a larger variety of obstacle types, and testing in unfamiliar environments.

In the literature, significant attention is also given to building design solutions tailored to individuals with mobility impairments. Among these articles, a clear theme is that further attention to areas of refuge for individuals with mobility impairments is needed. For instance, in McConnell and Boyce’s (2015) [75] study, 48.5% of respondents had never heard of an area of refuge in the past and only 7.9% had a full understanding of its purpose and use. A significant concern among individuals with mobility impairments regarding the use of areas of refuge is fear that they would be forgotten or that they would not receive timely communication from first responders. As a result, McConnell and Boyce (2015) [75] recommended that all areas of refuge be equipped with two-way communication systems and tools such as estimated wait time clocks.

Another theme among articles focused on individuals with mobility impairments is the need to leverage elevator usage during evacuations from high-rise buildings. These elevators can either be traditional passenger elevators modified for their safe use during emergencies or dedicated fire elevators for building occupants. Traditionally, elevator use has been prohibited during fire incidents in response to concerns regarding their safe performance during a fire [93,129]. These concerns stem from traditional elevators being vulnerable to fire and smoke, lacking water protection, and often having no backup power [76,93]. Yet, the current approach of using stairs to evacuate from high floors leads to long egress times, physical and mental fatigue for evacuees, increases vulnerability due to bottlenecks and stampedes, and places individuals with mobility impairments at a grave disadvantage [130]. Thankfully, current elevator technology allows for safeguarding measures that address the concerns surrounding traditional elevators being used during fires. As discussed by Kuligowski and Bukowski (2005) [76] and Liu et al. (2019) [93], these safeguarding measures include using positive pressure air supply, standby power, fire-resistant cables, water-tolerant components, and installing elevators in smoke-proof hoistways. Kuligowski and Bukowski (2005) [76] further proposed installing enclosed elevator lobbies to provide an area of refuge as occupants wait for an elevator. The lobby would also serve as a buffer to protect elevator hoistways from direct smoke or fire. Research surrounding the logistics of using elevators for evacuation from high-rise buildings is discussed in Section 4.5.

The change in perspective regarding building evacuation by elevators is especially noteworthy considering the growing trend of vertical cities with increasingly tall high-rise buildings [131]. Furthermore, the increase in the ageing population and chronic conditions that impact mobility prompt further exploration into safe evacuation solutions from high-rise buildings beyond stair egress. Elevators may present as an avenue for individuals with mobility impairments to evacuate without requiring assistance.

Nevertheless, it is important to note that, in many parts of the world, widespread change in building design habits may be required to accommodate elevator evacuations. For instance, Taipei, Taiwan, is a populated city with a high number of residential apartments (52% are three to five floors) along with an ageing population; yet, more than 40% of them do not have elevators according to Taiwan’s Ministry of the Interior [132]. The lack of elevators in buildings presents a serious challenge for escape during an emergency such as a fire, provided they would have otherwise been able to be used safely. Until a change in building codes or building design habits occurs, an increased emphasis on efficient and cost-effective stair descent devices for high-rise buildings continues to be needed.

Moreover, research into evacuation solutions that promote the independence of individuals with mobility impairments is also required.

The results also highlight how different building types often warrant unique building design solutions. For instance, Lena et al. (2012) [30] pointed to the challenge of improving the design of historical buildings for accessibility purposes while still being able to preserve important historical or cultural features. While the building design articles in this scoping review addressed high-rise buildings, hospitals, nursing homes, and airports, further attention to unique building types should be explored. It would also be valuable for researchers worldwide to continue disseminating research results on building design considerations unique to their countries, given that different countries often have unique building designs, demographics, and geographic challenges.

4.5. Strategy Solutions

While research into different evacuation devices and tools is important, it is equally valuable to evaluate strategies and logistical considerations for how to best use these devices to allow for an optimal evacuation. This section will discuss strategies around optimal elevator use, hospital evacuation order priority, evacuation plan dissemination to individuals with functional limitations, and the effective design of evacuation device instructions and wayfinding maps.

First, the results show that elevators can be a useful evacuation tool in high-rise buildings to decrease the evacuation time and the distance required to egress from buildings [93,95,96,97]. Moreover, there is evidence that clogging and aggregated evacuation times for all building occupants significantly decrease when wheelchair users utilize elevators for evacuation [95,96]. Despite the clear benefits of elevator usage, significant education, guidance, and reassurance for individuals with functional limitations is required before, during, and after emergency evacuations to reduce anxiety and increase trust in using elevators for evacuations [92,94,107]. For instance, it is important to provide timely information to occupants that supports decision making during an emergency through digital signs and voice announcements [94]. Some examples of visual and vocal messages include indicating the current status of an evacuation, which elevators can be used, and whether any priority protocols are in place [94]. There is also a need for continued research on the issue of elevator priority in an emergency. For example, while Minegishi (2020) [92] suggested that everyone should use elevators without discrimination on fire floors, Sekizawa and Nakahama (2011) [97] proposed exclusively reserving elevators for individuals with functional limitations. Meanwhile, Liu et al. (2019) [93] assessed the use of elevators on higher floors and stairs on lower floors. Future research should further clarify the issue of elevator priority, identifying whether any of the aforementioned evacuation priority strategies can be combined or optimized. Furthermore, there should be increased attention to managing the risk of elevator overcrowding or extended wait times during emergencies and monitoring whether the elevator priority will be honoured. While Butler et al. (2017) [94] provided suggestions on methods to promote elevator priority, it is yet to be seen how effective these methods are in a real-world scenario. In addition, all of the articles in our review that assessed the use of elevators either employed computer simulations or end-user interviews. As such, the dynamics of human behaviour were not considered. Finally, while there were many articles in our review on the use of elevators in high-rises, only one study assessed their use in hospitals. An increased emphasis on the optimal use of elevators in hospitals would be beneficial given the unique challenges in such an environment, such as complex building configurations, limited staffing resources, and often needing to transport patients within their hospital beds.

Second, there is disagreement in the literature regarding the priority order in which hospital patients should be evacuated in case of an emergency. Rega et al. (2010) [102] recommended implementing a reverse triage approach, which prioritizes the evacuation of ambulant patients to evacuate the largest number of patients in the least amount of time. This is in contrast to the study by Zou et al. (2020) [99], which advised the priority movement of wheelchair users in order to reduce interference in movement patterns with ambulant occupants, as well as to diminish the risk of blockages and allow for the improved evacuation efficiency for both populations. Meanwhile, Childers and Taaffe (2010) [101] acknowledged the ethical and resource availability challenges of prioritizing one patient class over another. As such, they recommended using multiple evacuation teams to alternate between critical and non-critically ill patients. To our knowledge, this is the first study to recommend an alternating evacuation prioritization strategy. Further research is needed to establish a consensus and a general guideline for patient prioritization during hospital evacuations. Another area of research is how the patient evacuation priority order can be combined with the strategic arrangement of patients in healthcare facilities. For instance, Li et al. (2020) [106] placed dependent elderly onto the lower floors of long-term care homes and independent elderly who could evacuate independently onto higher floors. Any dependent older adults prioritized for egress can be evacuated quickly given their proximity to ground level, allowing for quicker response times to aid semi-dependent or fully independent patients shortly thereafter. This strategy coincides with the building design study by Tzeng and Yin (2014) [79], which advised placing ICUs and other units with critically ill patients on the lower floors of hospitals to ease vertical evacuation efforts.

Third, the results highlight the importance of disseminating evacuation protocols to individuals with functional limitations prior to an evacuation. For instance, Feliciani et al. (2020) [89] found that informing wheelchair users of exit locations before an evacuation significantly reduced their evacuation time and improved surrounding crowd dynamics, decreasing congestion caused by wheelchair users unable to find accessible egress paths. The study underlines that prioritizing information provision to individuals with functional limitations may be more efficient and yield similar results compared to reaching out to the largest number of individuals possible. Communication of evacuation protocols can be realized in many forms, such as reserving time for staff members at historical buildings to identify individuals who may require support in an emergency and to briefly explain the accessibility of the building upon arrival [30]. This may be especially important in older building types with non-intuitive egress paths or facilities without accessibility information readily available online.

Fourth, a key implication of the results is to ensure that rescue device instructions are simple and easy to follow. As discussed by Boyce et al. (2017) [90], the complexity and presentation design of stair descent device instructions, such as whether salient visual cues were used, significantly influenced the device assembly time among participants. This strategy may be a suitable complement to the inclusion of operational cues within the design of rescue devices as discussed in Section 4.3. Providing intuitive instructions further extends to the ability of individuals with functional limitations to quickly process the area of refuge maps during a stressful evacuation setting. In fact, Carattin et al. (2016) [41] found that participants given wayfinding instructions had decreased pre-movement times and were less likely to demonstrate behaviour that was non-functional to the evacuation at hand. Future research should explore how the effective design of instructions and maps could be applied in other aspects of an evacuation, such as adhering to elevator priority measures and fire escape plans.

4.6. Training Program Solutions

Training rescuers and rescuees is an important part of ensuring that individuals with functional limitations can evacuate from buildings in an efficient and safe manner. This section will first discuss training programs for rescuers, followed by emergency preparedness programs for rescuees.

4.6.1. Rescuer Training Programs

The literature suggests that conducting mock evacuation drills for rescuers leads to improved staff confidence and competency in carrying out an emergency evacuation [108,110,111]. VanDevanter et al. (2017) [110] emphasized the need for more hands-on tabletop exercises as opposed to lecture-based training. The results also advise familiarizing rescuers with different evacuation equipment and improving communication with triage leaders at the time of an emergency [108,133]. While yearly drills are most common among organizations, it has been suggested that knowledge decay following evacuation training begins at approximately 3 months, and more frequent training may be required [109]. Nevertheless, a significant challenge reported is managing staff unavailability during training sessions and maintaining interest among busy staff members who need to quickly return to their duties and other obligations [108]. On that front, virtual reality technology has been suggested as an effective alternative to conventional methods of training. Virtual simulation training not only leads to improved disaster preparedness and communication as compared to lecture-based training; it also does not share the challenge of needing to train a large number of staff at the same time [109,133]. Since virtual reality can be implemented asynchronously with embedded software acting as a trainer and evaluator, virtual simulation training would theoretically be able to accommodate all staff on a schedule that is convenient for them, with limited trainers needed for implementation. While the initial upfront cost of implementing virtual simulation training is high, it is scalable at nearly no additional expense [109]. It also allows institutions to simulate scenarios that would otherwise be too expensive or dangerous to implement in a live exercise training program [109].

The findings also emphasize the need to improve the knowledge of staff in public facilities on building accessibility and to be able to effectively communicate that information to individuals with functional limitations [30]. As stated in Lena et al.’s (2012) [30] study, a common fear among study participants was not knowing whether a building was accessible before arriving at the facility. By training staff to provide this information along with any evacuation safety plans on a timely basis, a significant barrier to accessibility can be eliminated. One way to provide this training is by conducting an evacuation drill for staff members with individuals with functional limitations present, in order for staff to grasp how safe evacuation from a building can be adapted to different functional limitations [30]. It is worth noting that five of the six articles that assessed training programs for rescuers focused on staff in hospitals. Future research should identify the efficacy of training programs for different professionals in other building types.

4.6.2. Rescuee Training Programs

The rescuee subsection contained articles covering a wide variety of functional limitations, including children with complex health needs, individuals with mental health impairments, older adults, and individuals with mobility impairments. A recurring theme that emerged is that individuals with different functional limitations may require different training programs according to their needs and challenges when preparing for an emergency. For instance, some individuals with past traumatic exposure to disasters have been shown to not engage in risk reduction, despite completing general emergency preparedness training [134,135]. Yet, when Welton-Mitchell et al. (2018) [114] developed a mental health integrated disaster preparedness program, participants experienced increased disaster preparedness and reduced post-traumatic stress disorder-related symptoms. To provide another example, given that older adults are overrepresented in fire fatalities (refer to Section 4.1), nearly all of the training programs for older adults in our review focused on addressing fire safety, ensuring fire alarms were operational, and developing home fire escape plans [27,116,117,118,120]. With regard to individuals with hearing impairments, Caballero et al. (2019) [122] created a custom American Sign Language-based virtual reality tool for practicing disaster drills. As such, tailored emergency preparedness programs may be an effective approach to reducing disproportionate disaster preparedness among vulnerable populations, including individuals with functional limitations [136,137].

Another point of discussion among the articles was determining who would be most suitable to deliver emergency preparedness programs. Most articles proposed leveraging current touchpoints with the population at hand. For instance, Twyman et al. (2014) [118] proposed recruiting primary care nurses to support older adults in developing fire escape plans in the home environment. Meanwhile, Casteel et al. (2020) [116] recruited firefighters given that they are perceived as trustworthy among the general public and are in frequent contact with older adults through fire safety outreach efforts. There was also discussion of determining the most suitable intervention for improving emergency preparedness. While most articles in this subsection focused on developing training programs, Bagwell et al. (2016) [112] and Diekman et al. (2010) [120] proposed simple disaster supply and fire safety toolkits as a cost-effective and efficient way to facilitate information dissemination. These toolkits can be distributed at routine healthcare visits for children with complex health needs or with the aid of Meals on Wheels staff in routine contact with homebound older adults [112,120]. This approach would also require minimal training for professionals handing out the kits [112]. More research is needed to determine (1) the most optimal interventions and distribution mediums for different populations, and (2) any long-term disaster preparedness effects as a result of the interventions [112].

4.7. Emergency Types and Extreme Weather Events

Of the 30 articles that tailored their research to a specific emergency type, only five addressed evacuation solutions other than fire emergencies (i.e., large disasters, hurricanes, earthquakes, landslides). While preparing for fire emergencies is important, more work is needed to consider evacuations during other types of emergencies, including floods, power outages, terrorism threats, chemical or radiation leaks, or other extreme weather events. This area of future research is especially relevant when considering that extreme meteorological events may be increasing as a result of climate change [12,13]. It may also be useful to investigate how emergency types should be handled that require less urgency to evacuate individuals quickly while still requiring egress, such as power outages and floods.

4.8. Recommendations for Future Research

In this section, we summarized a list of recommendations presented in the above subsections categorized according to solution subtype:

4.8.1. Notification Solution Recommendations

• Continue to tailor the design and implementation of notification solutions according to the needs of individuals with different impairments including older adults and individuals with hearing loss. Solutions that target other impairments, including autism spectrum disorder, anxiety, or cognitive impairments remain largely absent.
• Consider solutions for building types that may require specialized engineering considerations in terms of notification approaches, such as correctional facilities and indoor stadiums.

4.8.2. Wayfinding Solution Recommendations

• Test wayfinding solutions in real-world environments, accounting for the interaction of individuals with functional limitations with crowds and first responders. Also, consider the impact of the use of wayfinding apps by the general public on overall evacuee safety and crowd dynamics.
• Employ a user-centred approach to wayfinding solutions, accounting for the unique needs and behaviours of individuals with functional limitations as they organically navigate buildings. An example of a population that would benefit from future research with regard to unique wayfinding solutions is individuals with cognitive impairments.
• Consider how effective wayfinding and egress solutions can overcome challenges associated with old or complex building types not designed for accessible egress.

4.8.3. Egress Solution Recommendations

• Conduct more hospital-focused studies in a simulated or real-world environment, considering the impact of evacuation devices on the flow dynamics of other evacuees and first responders. Consider nuances present in a real emergency, such as the rescue device preparation time, psychological and physiological stress factors present in an emergency setting, and the effect of poorly lit stairwells.
• Include the participation of both rescuers and rescuees in emergency evacuation planning and the assessment of optimal rescue devices. Further research should also continue to propose cost-effective evacuation devices that do not negatively impact the physical demands of the rescuer and the safety of the rescuee.
• Consider the differences in descending versus ascending to an exit and how different rescue devices may be needed.

4.8.4. Building Design Recommendations

• Complete further validation of the relationship between obstacle density and the ability of individuals with visual impairments to evacuate from buildings.
• Explore the potential of revising building codes to facilitate the integration of elevators that can be safely used by individuals with functional limitations during emergencies, including fires (see accompanied strategy recommendations below).
• Continue to pursue studies that consider egress from unique or structurally complex building types relevant to different regions of the world.

4.8.5. Strategy Recommendations

• While current technological limitations do not restrict evacuation by elevators during emergencies, further attention on strategies surrounding their use continues to be needed before they can be safely used.
  • Conduct further research to clarify optimal elevator priority strategies in case of an emergency, tailored according to building type, building height, building occupant demographics, or other situations as needed. Consider how these priority strategies can be enforced in a stressful evacuation setting through real-world simulations or other means.
  • Explore methods to manage the risk of elevator overcrowding or extended wait times during emergencies.
  • Further assess the use of elevators for evacuation in hospitals, given that most studies in this review focused on high-rise buildings.
  • Conduct more real-world studies assessing elevator use and strategies, as opposed to just computer simulations and end-user interviews.
• Establish consensus and general guidelines for patient egress priority order during hospital evacuations. Consider how these guidelines can be combined with the strategic arrangement of patients in healthcare facilities.
• Explore how the effective design of instructions and maps could be applied for other aspects of an evacuation, such as adhering to elevator priority measures and fire escape plans.

4.8.6. Training Program Recommendations

• Assess the use of training programs for rescuers in a diverse range of building types, given that most studies in this review focused on staff in hospitals.
• Conduct further research to compare and rank different interventions (i.e., training programs, disaster supply kits, etc.) and distribution mediums (i.e., primary care visits, home visits) to improve emergency preparedness for different populations with functional limitations.

4.9. Limitations of This Scoping Review

We acknowledge that broadening our inclusion could have resulted in identifying more relevant articles. Only articles published between January 2002 and February 2021 were included in this review. We did not consider grey literature, unpublished studies, or articles published in languages other than English.

Furthermore, our review did not include a formal critical appraisal of articles. Future work will be needed to assess the scientific rigour and quality of the articles before recommendations for evacuation guideline revisions can be made. Updated guidelines should also consider addressing the challenges faced by an individual after they have exited the building. These may include difficulty reaching a temporary shelter, ensuring that an individual has access to their mobility device once they exit from a building, having enough food and medication for the duration of their evacuation, or being appropriately triaged to a hospital.

5. Conclusions

This study synthesized the literature on egress solutions for different types of buildings. Our goal was to inform new evacuation guidelines/standards to help bring them closer to the ideal of providing equal life safety for all in the event of an emergency [9,138]. The 99 articles identified in our review were categorized into six groups of solutions that all need to be addressed in evacuation planning: notification, wayfinding, egress, building design, strategy, and training programs. Our findings indicate that individuals with different functional limitations have a range of different evacuation needs, yet past work has tended to largely focus on the needs of people with physical impairments. More focus is needed to address the needs of people with seeing, hearing, cognitive, and transient impairments.

Our review also found that while the ultimate goal may be to ensure all building users can “…egress from and evacuate a building independently in an equitable and dignified manner,” it may not be possible to attain this ideal in practice [138]. Indeed, in some cases, accommodating one functional limitation may impede the evacuation accessibility of an individual with another functional limitation. Further to this, there may be feasibility challenges or resource constraints that limit the ability to manage all needs at the same time. However, planning should include some capacity to accommodate any unmet needs on a case-by-case basis.

There should also be an increased emphasis on including individuals with functional limitations in emergency preparedness conversations and on embodying interdisciplinary work to coordinate different fields of expertise (e.g., architects, structural and software engineers, behavioural scientists, administrators, safety wardens, first responders) in creating and managing inclusive built environments.

Finally, we noted that there were increasing numbers of articles included in our review from more recent years may indicate a growing interest in this topic and we recommend repeating this type of scoping review to capture new work in this area. We hope our work will guide future systematic reviews with narrower scopes that can critically appraise the quality of their included articles as well as provide a more nuanced assessment for each of the solution subtypes we identified.