Small but Significant: A Review of Research on the Potential of Bus Shelters as Resilient Infrastructure

Abstract

Bus stops are an essential component of public transportation systems, significantly impacting human health, wellbeing, and overall user experience. As primary interaction points for passengers, they are integral to the urban landscape and, as such, their designs influence people’s experiences within the public realm. Despite their importance, the design of bus stops and bus shelters remains an under-researched area. This paper aims to review the existing peer-reviewed research on bus-stop design, identifying areas for future inquiry. Twenty-two peer-reviewed journal articles were selected and included in this study. The most common theme in the published research was the manner in which bus stops could address extreme weather and heat, along with other themes, including accessibility, sustainable energy, air pollution, and noise. Further empirical research is necessary to understand how bus-stop design affects the user experience, emphasizing qualitative methods to explore human experiences, perceptions, motivations, and challenges related to bus-stop usage and public transportation.

1. Introduction

Bus stops play vital roles in public transportation systems, impacting human health, wellbeing and overall rider experience. As primary interaction points for passengers, they are integral to the urban landscape and their designs influence people’s experience within the public realm. Bus stops are often considered the second-most visible aspect of public transport, next to the buses themselves [1]. Historically, the design of bus stops in Australia has been included in engineering infrastructure planning systems [2]. However, in recent years, interest has extended to the design fields, recognizing the potential for bus stops to contribute to better urban environments [3].

The crucial role of bus-stop design as a form of resilient infrastructure in everyday environments is frequently overlooked, despite notable impact on the urban landscape [3]. Resilient infrastructure is an important consideration for communities facing increasing risks from climate change and other vulnerable conditions. The Principles for Resilient Infrastructure developed by the UN Office of Disaster Risk Reduction highlights that one role of resilient infrastructure is to act as a buffer for societies facing extreme events [4]. Similarly, Infrastructure Australia [5] refers to resilient infrastructure within communities as having “the ability to resist, absorb, accommodate, recover, transform and thrive in a timely, effective manner in response to the effects of shocks and stresses to enable positive economic, social, environmental and governance outcomes”. Although there is considerable research related to public transportation’s ability to mitigate congestion [6] and promote environmental sustainability [7] and increased physical activity [8], the design aspects of bus stops remain a relatively under-researched area. This paper aims to address this knowledge gap in bus-stop design, placement and resilience by examining existing peer-reviewed research, identifying areas for further inquiry, and ultimately contributing to a better understanding of how bus stops can improve passenger experience and enhance urban environments. This review critically focusses on the key bus-shelter design considerations as essential infrastructure for bus stops.

Poorly designed bus stops that neglect local contexts and environmental conditions are associated with several negative implications, including diminished rider experience and perception of public transportation [1], increased exposure to extreme weather conditions [9], reduced bus ridership [10,11], and heightened vulnerability to air pollution [12]. While bus stops often feature shelters, their design should encompass more than the structure and consider multiple factors, such as placement on the street, adjacent uses, and orientation. The existing bus-stop research predominantly centres on engineering or planning disciplines, emphasizing technical aspects and spacing considerations relating to optimizing efficiency and functionality [3]. For example, research conducted in the USA in the 1990s using a survey associated with transit agencies found that there were three key factors to consider in bus-stop placement and design, including (1.) spacing between stops; (2.) street-side elements for the stop; and (3.) curbside elements for the stop [13]. Although these are important factors, the study did not investigate design solutions specific to bus stops. And research from 2012 in Australia focused on the spacing and placement of bus stops, recognizing that earlier research also focused on optimal spacing and location [14]. Additionally, accessibility and distribution are crucial factors for potential users [15]; placement and frequency relative to demand can influence travel time [14]. Ultimately, a more comprehensive and integrated approach to bus-stop design is needed to address the multifaceted nature of these considerations.

The design of bus stops necessitates a multifaceted approach and requires consideration of the reciprocal relationships with adjacent businesses and homes, as well as other land use-related considerations regarding access, traffic, noise, emissions, vehicle queuing and staging, road/rail network access, vehicle and passenger separation, and the pedestrian corridor, among others [16]. This approach aligns with the overarching concept that place, quality, and value can lead to better health-related, social, economic, and environmental outcomes [17]. The diverse needs associated with bus riders and their journeys necessitate designs that addresses numerous common requirements: walkability; comfort while waiting or boarding; and the ability to autonomously perform other travel functions, including purchasing tickets, getting information, and resting, as well as factors relating to the comprehension of signs and cues for wayfinding [18]. Given the varying circumstances bus-stop users may encounter (i.e., weather, purpose, location, and frequency of use), understanding bus stops as a system in which the main activities, waiting, boarding and alighting, are interrelated with other activities within the proximate environment is crucial for effective design.

To ensure that bus-stop design effectively addresses user needs and experiences, it is essential to examine users’ perceptions of bus stops. By gaining insights into how individuals interact with and perceive these spaces, we can better tailor design strategies to create bus stops that are more functional, comfortable, and appealing, and that enhance overall public transport experiences. Studies have shown that user perceptions of bus stops can vary from reality. In the state of New York in the USA, Hess investigated walking distances to transit stops for older people, finding that transit riders slightly overestimated the actual distance from their homes to the stops, while non-transit riders underestimated the distance [19]. A study in Minnesota in the USA investigated wait times for transit travel, revealing that passengers’ perceived wait times were, on average, 1.21 times longer than the observed wait times [20]. This research also demonstrated that basic amenities, including benches and shelters, significantly reduced perceived wait times, emphasizing the importance of providing such amenities at bus stops.

Bus-stop shelters aim to protect passengers from extreme heat and inclement weather conditions; much of the current research focuses on thermal comfort and shading. Although some studies did not meet the inclusion criteria for this systematic review due to their publication type (book chapters and conference papers), they offer valuable insights. For example, a study in India evaluated the passive cooling effects of tree shading on bus-stop structures, finding that while trees were effective, additional measures such as roof gardens might be necessary in hot summer conditions [21]. In Australia, a design competition and transdisciplinary project led to the development of innovative “climate-adapted people shelters” [22]. The project included the construction and testing of a prototype that demonstrated that the design impacted the radiation, temperature, and user thermal comfort, with the provision of shade being the most important factor, mediated by roof size and aspect.

In addition, numerous bus-stop-related reports and policy documents for cities, states, and regions worldwide play a significant role in shaping bus-stop design and installation, though they were not included in this systematic review due to their publication type. Despite the existing recommendations for context-specific designs, many bus shelters are prefabricated, and do not account for their unique context. This concern has persisted for decades, as evidenced in Christopher Alexander’s 1977 [23] seminal book, A Pattern Language: “Bus stops are often dreary because they are set down independently, with very little thought given to the experience of waiting there, to the relationships between the bus stop and its surroundings. They are places to stand idly, perhaps anxiously, waiting for the bus, always watching for the bus; nothing that would encourage people to use public transportation”. The statement highlights the need for more thoughtful design to encourage public transportation use, which remains a relevant concern today.

The primary aim of this review is to identify and synthesize the current peer-reviewed, published evidence on bus stops and identify gaps in the research. This review specifically focuses on the design of bus-stop shelters and offers an understanding of how they have been studied to date, which aspects have been considered and analysed, contextual details of the research, and major findings. The remaining sections of this paper include a description of the review methodology; a summary of findings; and a discussion of the implications and recommendations for future research.

2. Methods

This study utilizes a literature review methodology to examine both quantitative and qualitative methods and findings within peer-reviewed published research. This systematic approach effectively identifies, evaluates, and synthesizes available records to provide a comprehensive overview of the existing knowledge in the field. The research is guided by the following question: “What are the key bus-stop shelter design considerations emphasized in published peer-reviewed research?”

The review concentrates explicitly on bus shelters as a critical component of bus-stop infrastructure, deliberately omitting other aspects of bus service provision, such as the spacing between stops or the design of more intricate structures like bus stations or terminals. Despite the absence of shelters at some bus stops, this review underscores the significance of comprehending the design and functionality of bus shelters. By doing so, the study aims to optimize their role in augmenting the overall quality and efficiency of bus-stop facilities. By maintaining a concentrated focus on bus-stop shelter design, this review seeks to contribute valuable insights that can inform more effective and user-oriented approaches to urban transit infrastructure planning and development. Importantly, this review does not assert that every included study has the same level of quality and rigor in its research and findings, or that this study is an all-encompassing review of the topic. This review brings together a number of empirical studies in order to understand what they collectively offer to the emergent discussion on designing bus shelters as critical urban infrastructure for a more resilient community.

Informed by the Preferred Reporting Items for Systematic Reviews (PRISMA) updated guidelines for reporting reviews [24], this study conducts a comprehensive review to address the research question. This process offers a recognized methodology and a checklist to ensure the inclusion of all pertinent records. The review protocol consists of the search strategy, inclusion and exclusion criteria, data extraction, and analysis procedures, ensuring a thorough and dependable assessment of bus-stop shelter design considerations. By adhering to these guidelines, the study aims to provide a detailed understanding of how bus-stop shelters can enhance passenger comfort and protection while contributing to the overall quality and efficiency of public transportation infrastructure.

Search Strategy and Eligibility Criteria

An initial exploratory search was conducted to identify relevant search terms and databases. These searches and results were recorded. For the final export of records, Compendex, Scopus, and Web of Science were searched using the Title/Abstract/Keywords fields. The following search strings were used: (climate OR heat OR health OR sustainability) AND (“bus shelter” OR “bus stops” OR “bus shelters” OR “bus stops” OR “bus terminal” OR “bus terminals” OR “bus stop shelter” OR “bus stop shelters”).

No filters were applied, and all results were exported. The initial export contained 300 articles from Compendex, 576 articles from Scopus, and 326 articles from the Web of Science. In total, 1201 articles were imported into Endnote and the duplicate detection function was used to remove 237 duplicates. The remaining 964 articles were imported into Rayyan, an online tool for systematic literature reviews, where a further 101 duplicates were detected and removed. Titles and abstracts were screened and critically reviewed by the authors for the remaining 864 articles, using the inclusion and exclusion criteria. All discrepancies were resolved by consensus among the four authors. To highlight the significance of understanding current research in the areas of the design and functionality of bus shelters, this study applied the following inclusion criteria: English language or translations; empirical, peer-reviewed journal articles; studies regarding bus-stop shelters (not terminals or stations); and all publication dates. The search exclusion criteria included omitting other bus service operations such as the intervals of bus stops, and larger scale bus stations and terminals, to keep the study focused and aligned with the overarching research question.

The inclusion and exclusion criteria also required records to be peer-reviewed and to include empirical evidence of research. Records that could be described as the following were excluded from the systematic review: conference papers, books, and book chapters; opinion papers or editorials; systematic or narrative literature reviews that did not present original research; methodology papers that were only presenting methods used; and papers that did not focus specifically on bus stops or bus shelters, for example, if they focused on transit terminals or bus service provision.

The keywords “terminal” and “station” were included in the original search in case some papers used the words interchangeably. The appropriateness of the record and whether it met the inclusion/exclusion criteria was then determined by the authors. A total of 755 records were excluded by applying the exclusion criteria. This left 64 records for full-text download and review by the authors. Of these, 8 records were not available online, and another 34 records were excluded because of their topics, leaving 22 articles remaining for inclusion in the full review process. Figure 1 shows the selection process.

3. Results

Table 1. Summary information extracted from the included articles.

No.	Reference	Journal	Climate Code	Theme/ Focus	Data Types	Methods	Findings
1	Alikhanova et al., 2019 [26]	Sustainable Energy Technologies and Assessments	Bsk	Energy	Quant	Field surveys, technical and financial viability analysis, simulations	Heating from ground source heat pumps and grid electricity is sufficient even during extreme cold and wind.
2	Bikis and Pandey, 2022 [27]	Aerosol Science and Engineering	Cwb	Air pollution	Quant Qual	Tracking devices for air quality data, passenger interviews	324 of 720 respondents (45%) reported air quality-related diseases. Light rail transit proposed to reduce transport-related air pollution.
3	de Oliveira Santos et al., 2020 [28]	Applied Acoustics	Cfb	Noise	Quant	In situ sound pressure level measurements, statistical assessments	Tube-shaped shelters can effectively mitigate environmental noise.
4	Dzyuban et al., 2022 [9]	International Journal of Biometeorology	Bwh	Extreme weather: heat	Quant Qual	Field measurements for radiant temperatures, surface temperatures for materials, and rider perception surveys	Shading at shelters decreased personal equivalent temperature. Bus stops with better design attributes increased favourable user perceptions.
5	Koscikova and Krivtsov, 2023 [29]	Land	Cfb	Extreme weather: cold/rain	Quant	Benefits Estimation Tool (B£ST), combined with manual calculations	Quantification of extensive and intensive green roofs on bus shelters results in a total-benefit present value, with social gains exceeding environmental benefits.
6	Kyogoku and Takebayashi, 2023 [30]	Atmosphere	Cfa	Extreme weather: heat	Quant	Field measurements for heat and humidity to analyse effects of mist spray	A mist spray system at semi-open bus stops decreased air temperature and increased humidity slightly, but measures of human comfort were not available.
7	Lan et al., 2024 [31]	Urban Climate	Cwa	Air pollution	Quant	Comparative observational experiment	Findings recommended that urban planning and designs include more open diffusion environments for bus-stop locations to avoid high concentrations of particulates in street canyon environments
8	Lanza and Durand, 2021 [11]	International Journal of Environmental Research and Public Health	Cfa	Extreme weather: heat	Quant	Measured bus ridership, temperature, tree canopy; socio-demographic and statistical analyses	Shelters and trees had insignificant or modest effects on ridership during high temperatures, as the process is more related to transport dependency. Tree canopies can be a positive.
9	Lee and First, 2023 [32]	Sustainability	Cfa	Extreme weather: heat	Quant	Data sources from satellite and ground measures of heat and humidity, characteristics of land surface and cover, social vulnerability index	Most heat-vulnerable bus stops are poor microenvironments without trees and shelters. Impervious surfaces account for the majority of the cover in densely populated areas with high social vulnerability
10	Miao, Welch, and Siraj, 2019 [10]	Journal of Transport Geography	Csa	Extreme weather: heat/cold/rain	Quant	Field measurements of weather, ridership and bus-stop characteristics	Stops with shelters are more valued. Shelters can modestly moderate the negative effects of adverse weather on ridership. Benefits of shelters geographically dependent.
11	Mokhtari, Ulpiani, and Ghasempour, 2022 [33]	Applied Thermal Engineering	Bsk	Extreme weather: heat	Quant	Application of daytime radiative cooling technology and simulations for other climates	Cooling stations can reduce urban thermal comfort levels by up to 10 °C and enhance thermal comfort in summer.
12	Montero-Gutiérrez et al., 2023 [34]	Energy Conversion and Management	Csa	Extreme weather: heat	Quant	Experimental prototype modelled within a climate-controlled chamber and a sensorized thermal camera	Implementing climate shelters in hot, dry climates may provide a solution for issues relating to thermal comfort. In the prototype, 50% of the cooling flow was radiative.
13	Montero-Gutiérrez et al., 2024 [35]	Energy and Buildings	Csa	Extreme weather: heat	Quant	Thermal characterisation model using an experimental prototype	The prototype used a Falling-Film with associated climate shelter geometries to reduce the Heat Load Comfort Index by up to 50% on unfavourable days.
14	Noh et al., 2021 [36]	Journal of Mechanical Science and Technology	Dwa	Air pollution	Quant	Numerical testing, simulations for dust particles	Canopy-type air-blast structure was most effective at decreasing particle entry into bus stops, with curve fence model predicted to reduce dust by 88%.
15	Pan et al., 2024 [37]	Buildings	Cwa	Extreme weather: heat	Quant	Google Street View map and field investigations for orientation and materials. Air temperature, relative humidity, black globe temperature, wind speed, solar radiation intensity. Systematic observations and photos of behaviours indicative of thermal discomfort	Guangzhou’s most common bus-shelter design offers limited thermal comfort, leading to high air temperatures and humidity levels during summer, prompting passengers to seek additional cooling measures and adjust their positioning to minimize solar radiation exposure.
16	Pinto et al., 2020 [38]	International Journal of Sustainable Development and Planning	Csa	Accessibility	Quant, Qual	Questionnaire for respondents aged 60+ on mobility and perceptions at airports	Tactile pavement at bus stops was perceived as less important by senior tourists (80+), females, and tourists with disabilities.
17	Rosa et al., 2020 [39]	International Journal of Sustainable Development and Planning	Csa	Accessibility	Quant, Qual	Perception questionnaire for tourists aged 60+ regarding bus stops at airports	Tourists age 60+ with disabilities were more aware and critical of the accessibility of bus-stop amenity, surrounds and space.
18	Santos et al., 2020 [1]	Applied Sciences	Csb	Energy	Quant	Case study assessing bus-shelter photovoltaic (PV) potential, with GIS mapping and digital surface modelling	612 bus shelters (54%) in Lisbon receive sufficient solar radiation for PV panels; these units have the potential to be improved to include amenities.
19	Velasco and Segovia, 2024 [12]	Smart and Sustainable Built Environment	Af	Air pollution	Quant	Measurements of mass concentrations of fine particles and black carbon to compare two shelters. Air temperature, relative humidity, and noise level were also measured.	The new Airbitat bus shelter was unable to significantly reduce particle load and heat for bus-stop users.
20	Wang et al., 2024 [40]	Sustainable Cities and Society	Cfa	Air Pollution	Quant, Qual	Field measurements, installation of hedges to measure PM2.5 concentrations before and after and risk assessment models for health risk reduction	Installing green hedges significantly reduced PM2.5 concentrations at bus stops, and mitigated health risks from PM2.5 pollutant to below safety threshold. The highest hedge was the most effective against particulate exposure.
21	Yoo et al., 2024 [41]	Sustainable Cities and Society	Dwa	Air pollution	Quant	Simulations to identify optimal installation for air purification systems	Significant reductions in pollutant levels and decreases in health risk
22	Zhang et al., 2021 [42]	Sustainable Cities and Society	Cwa	Extreme weather: heat	Quant, Qual	Experimental test: mist spray system modelled to simulate real environment; thermal comfort assessment using a questionnaire	Mist spray system reduced average air temperature and thermal comfort increased; 74% of participants would accept the mist spray system.

Climate code legend from the Köppen Climate Classification system: Af: Tropical Rainforest; Bsk: Arid, Semi-Arid, Cold; Bwh: Arid, Arid Desert, Hot; Cfa: Temperate, No Dry Season, Hot Summer; Cfb: Temperate, No Dry Season, Warm Summer; Csa: Temperate, Dry Summer, Hot Summer; Csb: Temperate, Dry Summer, Warm Summer; Cwa: Temperate, Dry Winter, Hot Summer; Cwb: Temperate, Dry Winter, Warm Summer; Dwa: Continental, Dry Winter, Hot Summer.

provides a summary of the 22 full-text, peer-reviewed, empirical journal articles that met the established inclusion and exclusion criteria. These articles offer valuable insights into crucial bus-stop design considerations, thereby enhancing the overall understanding of the subject matter. To facilitate a broader perspective, the research locations were categorized using the Köppen Climate Classification system, which categorizes climates into five primary groups: A (tropical), B (arid), C (temperate), D (continental), and E (polar) [25]. The following sections will elaborate on the findings gleaned from these articles.

This section presents the results of our systematic literature review on bus-stop shelter design, exploring the key themes, geographical distribution, and methodological approaches found within the 22 selected peer-reviewed articles.

3.1. Publication Year and Study Locations

While the literature search included all possible publication dates, the 22 records included in this review were published between 2019 and 2024 (see Figure 2 for a breakdown of articles by publication year). This observation suggests that while empirical research on bus-stop shelters may have been conducted prior to 2019, the increase in peer-reviewed journal publications is a relatively recent development, indicating a growing interest and an emerging trend in this research area. It is essential to acknowledge that earlier research can be found in book chapters, conference papers, and reports, further enriching the overall knowledge base focusing on bus-stop design. However, we specifically chose to only include peer-reviewed journal articles in this review as a way to control quality and research rigor.

The reviewed publications are geographically diverse, with ten articles reporting research conducted in Asia (four from China, two from South Korea, and one each from Singapore, Japan, Kazakhstan, and Iran). Six articles reported research completed in Southwestern Europe, including three from Portugal, two from Spain, and one from the UK. Four articles involved research from North America, specifically, the United States, with studies taking place in Texas, Arizona, Tennessee, and Utah. Additionally, one article reported on research from South America (Brazil) and one from Africa (Ethiopia). Figure 3 shows the geographic distribution of the study locations, mapped according to country. This distribution highlights a lack of studies that have taken place within the southern hemisphere, and none of the included studies were from Australia.

Although the studies exhibit geographic diversity, the Köppen Climate Classification, as applied to the research locations, is less varied (see Figure 4). Most research has focused on temperate regions with hot or warm summer climates. This geographical bias may explain the emphasis on bus stops in extreme weather and heat, as these regions face distinct challenges in providing comfortable and safe waiting environments for passengers. However, it also reveals potential gaps in the research conducted in climate regions other than those experiencing extreme weather and high temperatures.

3.2. Methodological Approaches Reported

To gain insight into the various research approaches applied to bus-stop studies, we examined the methodologies reported in each article. This analysis revealed the diverse strategies employed by researchers to investigate bus-stop design, functionality, and user experiences. Out of the twenty-two articles, seventeen used solely quantitative methods, while five combined qualitative and quantitative methods. No articles relied solely on qualitative methods, indicating a strong trend toward quantitative measurements.

Common methods included empirical field measurements at bus-stop sites, such as heat load calculations, technical and financial viability analyses, air quality assessments, pressure levels, meteorological measurements, surface temperature readings, relative humidity levels, solar radiation levels, simulations and prototype testing, and the impact of tree canopy shade on bus ridership. Qualitative methods were employed in some studies, primarily involving user perception surveys used to gauge heat perception, coping behaviours, and awareness of accessibility and amenities at bus stops.

In this review, the majority of articles employed diverse methodologies, ranging from highly technical approaches to more straightforward techniques. The heterogeneity of these methods precluded direct comparability between studies. Among the articles reviewed, four studies [30,33,35,42] focused specifically on interventions in extreme weather conditions. Notably, two interventions utilized mist spray systems [30,42]. However, these systems differed in technology and study data collection methods. The remaining interventions introduced novel materials and systems [33,35] aimed at improving thermal comfort in bus stops. While the Montero-Gutiérrez et al. study [35] examined a single prototype within specific climate shelter geometries, Mokhtari et al. [33] expanded their investigation to various climates and demonstrated that cooling stations can reduce urban thermal discomfort by up to 10 °C in arid and semi-arid climates. Both technologies were modelled and simulated for large-scale use.

This multifaceted approach demonstrates the depth and breadth of research in the field. However, it also highlights a need for additional qualitative research to ascertain user experience and perceptions. See Figure 5 for a visual representation of the relative frequency of methods used across the articles, noting that many articles utilized more than one method.

3.3. Themes Covered Across the Included Articles

The 22 reviewed articles were organized under five primary themes, with extreme weather conditions emerging as the most extensively explored topic, featuring in 11 articles. Within this category, nine articles concentrated on heat-related aspects [9,11,30,32,33,34,35,36,37,42], while one article discussed general extreme weather conditions [10] and another focused on estimating climate change mitigation through the built environment [29].

The remaining articles covered a range of themes: six examined air pollution [1,31,38,39,40,41], two focused on accessibility [38,39], two explored energy-related aspects [1,43], and one concentrated on noise pollution [28]. These diverse themes emphasize the wide array of factors considered in bus-stop shelter design, underlining the importance of addressing various environmental, social, and health concerns to create optimal public transportation infrastructure. Figure 6 shows the distribution of key themes across the reviewed articles.

3.3.1. Extreme Weather and Heat

In response to the increased temperatures and extreme weather events resulting from climate change and the urban heat-island effect, 11 of the 22 articles examined the potential of bus-stop shelters to mitigate these conditions.

A study conducted in Edinburgh investigated the potential ecosystem services provided by green roofs (GRs) on bus shelters in urban areas, focusing on their role in mitigating climate change [29]. Relying solely on previous literature and employing the estimation tool Benefits of Extensive Green Roofs for Sustainable Towns (B£ST), the study analysed the environmental and social advantages of extensive GRs. The social aspect encompassed amenity, education, and health benefits, with an estimated 322,287 residents potentially benefiting from GRs on bus stops. Notably, social benefits were found to have a significantly higher value than environmental benefits. The B£ST tool distinguishes between regulating benefits (air quality, carbon sequestration, stormwater runoff, and urban heat island) and supporting benefits (biodiversity); these are collectively categorized as environmental benefits in this study. The analysis revealed that installing extensive GRs on all sheltered bus stops in Edinburgh would result in higher costs than benefits, considering confidence scores (−£3.1 million net present value). However, given the reliance on assumptions and B£ST guidance, these findings may be inaccurate. Therefore, an experimental study is recommended to eliminate uncertainties and obtain more precise results. User perceptions of bus stops during extreme weather events, including elevated temperatures, were also an important factor discussed.

A study in Austin, Texas [11], investigated the impact of tree canopy shade and shelters at bus stops functioning as a climate change strategy. The findings showed insignificant or modest associations between these strategies and ridership during high-temperature days, with bus stops lacking tree canopy associated with only a 1.7% decrease in boardings per bus on high temperature days compared to other days. However, the study highlighted the moderating effect of trees on temperature and the impact on user perceptions, suggesting a link between tree shade and positive association for bus ridership, particularly in city areas with low socio-economic metrics [11].

Research from Utah in the USA [12] investigated the influence of extreme weather, including high and low temperatures and heavy rainfall, on ridership, and the potential mitigation effects of stop-level amenities. The study found that extreme weather generally decreases daily passenger boardings, with sheltered bus stops experiencing only slightly higher ridership, relative to unsheltered bus stops, during extreme weather conditions. The moderating effects of bus shelters were more pronounced on weekdays than on weekends, suggesting that the transit amenities providing weather protection are more valued by regular commuters and passengers with longer wait times.

A study conducted in Phoenix, Arizona, USA, examined the perceptions of heat and heat-coping behaviours at bus stops [9]. Using micrometeorological measurements and rider surveys and conducted during the summer, its findings revealed that over half of participants reported feeling thermally uncomfortable. Shade at stops significantly reduced the physiological equivalent temperature by 19 °C. The study evaluated various design attributes and discovered that vegetated awnings only provided significant shade reduction in the mornings due to poor maintenance, while opaque canopies were more effective than semi-opaque canopies. Surface temperatures of sun-exposed materials exceeded skin-burn thresholds during the afternoon. However, aesthetically pleasing stops, including those with trees, were rated as cooler than stops rated as less beautiful.

To investigate the distribution, orientation, and thermal environment of 373 bus shelters in Guangzhou’s hot–humid climate, researchers classified bus-shelter characteristics and identified typical styles, while measuring thermal conditions and observing passenger cooling behaviours during summer [37]. The findings revealed that the typical bus-shelter style in Guangzhou’s core area features a north–south orientation, single station board, two backboards, two opaque green roofs, and a red permeable brick surface. Air temperature and relative humidity under various bus shelters in various tree-shaded areas and in open spaces ranged within 34–37 °C and 49–56%, respectively. At high-traffic bus shelters, air temperature generally exceeded 35.5 °C, indicating an uncomfortable thermal environment. In the absence of shade from bus shelters or trees, passengers adjusted their positions in response to sun height, azimuth angles, and direct solar radiation intensity to minimize radiation exposure. When only bus shelters provided shade, people congregated in shaded areas, employing additional cooling measures like umbrellas, hats, and small fans to mitigate thermal discomfort. Despite these efforts, overheating persisted, highlighting the importance of integrating auxiliary cooling facilities in bus shelters to improve thermal comfort [37].

In a study examining the local microenvironment and social vulnerability of heat-vulnerable bus stops in Knoxville, Tennessee, researchers utilized publicly available data from multiple sources, including ground and satellite measurements of heat and humidity from the Knoxville Heat Mapping Campaign, land surface characteristics from the National Land Cover Dataset 2019 of the United States Geological Survey, and the 2018 Social Vulnerability Index from the U.S. Centers for Disease Control and Prevention [32]. The study employed a geographic information system and principal component analysis to identify social vulnerability in areas surrounding bus stops. The findings revealed that most heat-vulnerable bus stops lacked trees and shelters, contributing to poor microenvironments. Moreover, the hottest bus stops were concentrated in the densely populated and highly developed areas of Knoxville. These regions exhibited relatively high vulnerability clustering and inadequate public infrastructure.

Research on the effectiveness of mist-spraying as a heat mitigation technique at bus stops has yielded mixed results. A study from Japan [34] explored the cooling effects of mist-spraying techniques at semi-open bus stops, aiming to determine the ratio of air temperature decrease and humidity increase where the mist was sprayed. The findings show that the air temperature decreased by 1 °C and humidity increased by 1 g/kg (DA) under low-wind conditions, only slightly mitigating the solar radiation. Conversely, a study in China [19] focused on a mist spray system to improve outdoor human thermal comfort, using experimental testing and a questionnaire. The results indicated that 74% of participants (N = 50) found the mist spray system acceptable and that it significantly improved thermal comfort and thermal sensation.

Three of the studies that focused on heat investigated radiant cooling used to create cool shelters. Kyogoku et al. [30] reported findings on radiant cooling for bus shelters in Iran. The study combined radiative cooling with dynamic radiant cooling technology to develop a “Cooling Station” and evaluated the effects of geometry, orientation, and surrounding elements on the station’s climate. The results demonstrate that humidity and the surrounding buildings could diminish the performance of the cooling panels. However, by applying non-reciprocal asymmetric transmission windows, this impact could be mitigated. With optimization, the “Cooling Station” was capable of a 10 °C decrease in the Universal Thermal Climate Index, showcasing its potential as an effective solution for the improvement of thermal comfort at bus stops in hot climates.

Similarly, experimental research by Montero-Gutierrez et al. [34] used a radiant cooling system to lower the temperatures on the surfaces of a bus-shelter prototype within a controlled climate chamber to test the cooling capacity of the prototype. The climate chamber employed artificial climate simulation to test different climate conditions and measure thermal comfort. The findings suggest that short-stay climate shelters used as bus stops could potentially offer cooling benefits for pedestrians within hot and dry climates. However, climate variables, such as humidity, wind speed, and wind direction, that directly affect the occupant’s thermal sensation, were not tested.

Expanding on the experimental study discussed in Montero-Gutierrez et al. [35], the authors develop a methodology to identify the key variables involved in designing and implementing short-term climate refuges in order to enable replicability across other cities. Through mathematical modelling, the research calculates suitable Falling-Film storage volumes and energy-harvesting areas for specific shelter geometries. This study highlights the importance of considering site-specific factors, including height-to-width aspect ratio, orientation of the urban canyon, the geometry of the shelter, and the degree of confinement of the stop. The study also calculates the COMFA comfort index (heat load factor index), which is used to quantify the reduction of thermal stress and efficiency of the shelter. The modelling shows that COMFA is reduced by up to 50% on very unfavourable days, showing progress in optimizing the design of short-term climate refuges.

3.3.2. Accessibility

Two articles included in this review discuss findings from the ACCES4ALL project, focusing on accessibility for senior tourists aged 60+ at bus stops in Portugal. Pinto et al. [38] explored age-friendly and inclusive bus-stop design, finding that the perceived importance of pedestrian crossings with dropped curbs and tactile paving in boarding areas was lower for female participants and those aged 80+ years. While tactile paving surfaces can benefit visually impaired individuals, the authors highlight the need to minimize discomfort for sighted people. They suggest that colour contrast may be helpful, but warn that excessive or improper installations could negatively affect public opinion.

Further elaborating on ACCES4ALL, the research presented in [39] reported on senior tourists’ perceptions of bus-stop environment attributes. The study found that senior tourists with mobility-related disabilities were more critical of attributes impacting their travel abilities. The top universal, accessibility-related bus-stop attributes identified by senior tourists (with or without disabilities) in their respective countries include barrier-free sidewalks, obstacle-free areas around bus stops, sufficient wheelchair space, and non-slip sidewalk pavement.

3.3.3. Sustainable Energy

Two of the included articles centred on energy, specifically the incorporation of green energy and the potential application of photovoltaic technology in bus-stop shelters. Alikhanova et al. [26] modeled energetic systems to assess the technical and financial viability of a “warm” bus shelter in Nur-Sultan, Kazakhstan. The study integrated passenger load surveys to estimate maximum daily ridership, determine the shelter’s heating load and power demand, and examine three green technologies: ground source heat pumps, photovoltaic arrays, and wind turbines. The findings showed that a combination of 40% ground source heat pump and 60% electric heat was a feasible and attractive option.

In a separate study, Santos [1] explored the photovoltaic potential of bus-stop shelters in Lisbon, Portugal. The researchers utilized Geographic Information Systems-based solar radiation maps to pinpoint suitable locations, as well as proxies for tourist and commuter demand. Additionally, they conducted visual analyses via ortho-photo and Google Street View tools. The results revealed that 54% of the existing shelters in Lisbon hold potential for photovoltaic systems, which could contribute to local electricity production. These two studies underscore the increasing interest in integrating sustainable energy solutions into bus-stop shelter design.

3.3.4. Air Pollution

Six articles specifically addressed air pollution concerns at bus shelters due to their proximity to main roads with potentially high concentrations of air pollutants.

Noh et al. [36] focused on resuspended road dust dispersed by vehicles in Seoul, South Korea, and its impact on users of roadside bus shelters. Simulation models identified the most effective bus-stop design for reducing fine dust entry, with a combination of a curved fence and a canopy-type air-blast system showing an 88% reduction in particulate matter compared to a fence-free model.

Bikis and Pandey [27] investigated air quality at transportation stops in Ethiopia, revealing unhealthy levels of air quality, particularly at busy intersections. Pan et al. [37] researched short-term exposure to ultrafine particle pollution at bus shelters in street canyon environments in Guangzhou, China, with higher pollution levels recorded near 2–3 floor buildings compared to open spaces.

In 2024, Velasco and Segovia [12] evaluated the Airbitat Oasis Bus Stop’s ability to provide clean and cool air in Singapore. Despite the prototype’s integrated cooling and filtering systems, the study showed only slight reductions in fine particles, air temperature, and increased relative humidity.

Yoo et al. [41] reported on a design plan for air purification systems at two bus stops in an industrial South Korean city, utilizing computational fluid dynamics simulation to optimize system placement and analyse pollutant concentrations.

Lastly, Wang et al., examined the potential of vegetation in reducing airborne pollution in Nanjing City, China, with 1.5 m-high hedges proving most successful in filtering particulate matter [40].

These studies collectively highlight the significant concern of air pollution in urban environments and the need for effective strategies to minimize exposure of bus users to fine particulate matter (PM_2.5).

3.3.5. Noise Pollution

A single article in this review focused on noise pollution at bus stops. De Oliveira Santos et al. investigated noise pollution’s impact on physical and mental health globally and considered tube-shaped bus shelters used to mitigate environmental noise [28]. The study measured sound levels inside and outside 40 shelters in Curitiba, Brazil, concluding that tube-shaped shelters significantly attenuate sound pressure levels, benefiting public transport users and emphasizing the importance of noise reduction measures in bus-shelter design.

4. Discussion

This systematic review reveals a noticeable scarcity of peer-reviewed publications on bus-stop shelter design, with a mere 22 articles meeting the inclusion criteria. This limited research underscores a substantial knowledge gap in this topic area, particularly considering the significance of bus stops and bus shelters within the transportation network and the potential implications for human experiences and interactions in these spaces. This review contributes to this important research topic by analysing empirical studies and presenting their findings through organized thematic groups in a tabular format. The findings have been synthesized to illustrate the gaps in research and highlight key areas for future consideration.

Although bus-stop shelters may be relatively small in scale, their impact as critical components of resilient infrastructure should not be underestimated. As essential elements of the public transportation system and the urban environment, they play a vital role in impacting user experience and facilitating sustainable mobility [3,14,15]. The five themes identified within the 22 reviewed articles emphasize the multifaceted aspects of bus-stop shelter design, encompassing environmental concerns, user experience, and public health implications.

Protection from extreme weather conditions emerged as the most prominent theme, with 11 articles focusing primarily on heat-related issues, although rain and cold weather were also included factors in a few studies. This focus reflects the global rise in temperature and extreme weather events occurring due to urban heat-island effects and climate change [9], and their impacts on people within urban environments. In addition, almost all articles examined the impacts of environmental factors on health and well-being, such as air and noise pollution, heat, and accessibility. These findings highlight the need to design shelters that can mitigate the adverse effects of high temperatures and other environmental conditions on commuters [9,20,21]. Moreover, articles addressing extreme weather conditions and climate change mitigation in general emphasize the importance of considering long-term impacts in bus-stop shelter design, further emphasizing the potential roles of these structures in fostering urban resilience [22,23]. While the need for bus shelters to contribute to resilient city infrastructure and provide refuge from extreme weather conditions is considered important, it was highlighted in the literature that legislation and manufacturing processes can impede opportunities that would enable bus shelters to be thermally comfortable and context specific [9,11] The value of tree shade was confirmed as contributing to a reduction in temperatures and a positive association for bus users

In light of public health concerns, there is an increasing need to explore how thoughtfully designed bus shelters can mitigate exposure to harmful environmental factors. Globally, in 2020, the World Health Organization (WHO) reported that excessive UV radiation exposure caused approximately 1.2 million new cases of non-melanoma skin cancers (SCC and BCC) and 325,000 melanomas in 2020 [44]. Additionally, ambient (outdoor) air pollution contributes to 4.2 million premature deaths annually, primarily due to exposure to fine particulate matter, which results in cardiovascular and respiratory diseases and cancers [45].

Air pollution was another prominent theme, discussed in six articles, emphasizing the significance of the integration of strategies such as innovative shelter designs and air purification systems to minimize the exposure of bus-stop users to harmful pollutants [12,41]. In a similar vein, the article on noise pollution demonstrates the importance of addressing this often-overlooked aspect of the urban environment in bus-stop design, highlighting the potential of these structures to contribute to overall urban well-being [28].

Accessibility was another theme, covered in two articles, accentuating the need to ensure that bus-stop shelters accommodate the diverse needs and abilities of all users [3]. This entails designing inclusive infrastructure that promotes a comfortable and convenient experience for everyone, including older adults, individuals with disabilities, and families with young children [15,46]. Despite the awareness of designing spaces for diverse populations, the research on this topic was lacking.

Energy-related aspects were discussed in two articles, underscoring the importance of incorporating sustainable and energy-efficient solutions in bus-stop design. This not only contributes to environmental sustainability, but also ensures the optimal functioning and cost-effectiveness of these public transport facilities, showcasing their potential as elements of resilient infrastructure that can adapt to changing environmental conditions [7].

Apart from the intervention studies [30,33,34,35,42], other research efforts heavily relied on manual calculations [29], numerical testing [36], and statistical modelling [1,29,30,40]. These studies covered a broad range of shelter types and were applicable across numerous contexts. The findings from these statistical modelling studies were instrumental in informing bus-stop designs, performing thermal comfort assessments, and determining implications for policy-making within the public transportation sector.

Given the findings of this review and the increasing prevalence of extreme weather events due to climate change and the urban heat-island effect, further research on how bus stops impact user experience, including thermal comfort and protection from the climatic elements, is crucial. A focus on vulnerable populations that may rely on bus transportation for everyday needs, including older people and children and youth, is also warranted. Incorporating qualitative methods to study human experiences, perceptions, motivations, and challenges related to bus-stop and public transportation use would provide valuable insights. Although existing research suggests that bus ridership is only minimally affected by heat and extreme weather, more investigation is needed to explore the impacts on different population groups and potential alternative travel solutions.

Research recommendations include a continued increase in the number of empirical, peer-reviewed articles on bus stops and bus-stop shelters, as current research remains in its early stages. While there is a body of research on the broader public transportation systems, studies focusing on the specific designs and implications of bus stops and shelters are relatively recent. The global focus on urban resilience and the manner in which infrastructure can support and enable populations to be resilient to climate change and extreme weather events suggests a greater need for research in this area. Additional research on how the design of bus stops can enhance resilience to heat and extreme weather, in addition to air pollution within urban contexts, is needed. A better understanding of how bus stops can contribute to a wider network of resilient infrastructure should help determine their contributions to urban environments. In addition, further research is needed on the use of vegetation, shade structures, and other amenities intended to help with the thermal comfort of people waiting at bus stops is needed as climate change and urban heat islands impact temperatures [47]. By addressing these research gaps and considering the complex interplay between environmental factors, user experience, and public health, we can enhance the design and functionality of bus-stop shelters to better serve diverse user needs and contribute to sustainable and resilient urban environments.

5. Conclusions

Bus-stop shelters, as integral components of public transportation systems, significantly influence the interactions between individuals and urban environments. A systematic examination of the existing literature on bus-stop design reveals a paucity of research in this domain, highlighting the need for further inquiry. While preliminary studies have explored the effects of environmental factors such as heat, ultraviolet radiation, extreme weather, and air pollution on bus-stop environments, additional research is necessary to address contemporary challenges.

As urban areas increasingly prioritize sustainable public transportation solutions in response to climate change and urbanization, understanding how bus stops and shelters can contribute positively as resilient urban infrastructure is crucial. This knowledge will inform the development of public transportation systems that are more user-friendly, environmentally sustainable, and adaptable for diverse user groups and communities.

In light of the reviewed articles’ multifaceted themes, it is evident that a comprehensive approach to bus-stop shelter design is essential. Addressing environmental, social, and health concerns will contribute to the creation of sustainable and user-friendly public transportation infrastructure. Future research efforts should continue to explore these vital aspects and pursue innovative solutions to further improve bus-stop shelter design and functionality, ultimately enhancing the user experience and promoting urban resilience.