Exploring Sidewalk Built Environment Design Strategies to Promote Walkability in Tropical Humid Climates

Abstract

The world is facing a state of “global boiling,” causing damage to various sectors. Developing pedestrian systems is a key to mitigating it, especially in tropical and humid cities where the climate discourages walking and increases the need for shaded walkways. Recent research shows a lack of data and in-depth studies on the built environment promoting walkability in such climates, creating a research gap this study aims to fill. Using Singapore as a case study, four locations—Marina Bay, Orchard Road, Boat Quay, and Chinatown—were surveyed and analyzed through visual decoding and questionnaires. Results show that natural light is the most frequently observed and important element in pedestrian pathway design in tropical and humid areas. Trees and sidewalks are also important in creating a walk-friendly environment. Green spaces significantly influence the desire to walk, though no clear positive outcomes were found. Additionally, “Other Emotions” negatively affect the decision to walk, suggesting these should be avoided in future pedestrian pathway designs to encourage walking.

1. Introduction

Our world is currently facing not only global warming but also entering a state of “global boiling,” which is causing damage to the economy, the tourism industry, and the agricultural sector [1,2]. Moreover, it has a closer impact on our daily lives than we might expect, affecting both physical and mental health to the point of being fatal [3,4,5,6,7,8]. The rise in global temperatures calls for both mitigation and adaptation to climate change [9,10,11]. It is time we recognize and prioritize this critical issue—at the very least, by taking action to slow the progression of global boiling [12,13].

According to previous studies, slowing down the progression of global boiling requires a significant reduction in greenhouse gas emissions [14,15]. Previous research has found that the primary cause of the sharp increase in greenhouse gas emissions is the transportation sector and particularly the rising use of automobiles [16,17,18].

Nowadays, society has been focusing on controlling the increasing use of automobiles. One proposed solution is to improve the accessibility of public transportation in urban areas, using effective measures and certification systems such as Leadership in Energy and Environmental Design for Neighborhood Development (LEED-ND) [18,19,20,21,22,23]. One practical step for immediate change is supporting the development and enhancement of pedestrian infrastructure [24,25].

Supporting the development of pedestrian infrastructure can contribute to social development in various sectors that are affected by global boiling—even on the individual level, such as health [21,26,27,28,29,30,31,32]. Walking plays a role in physical recovery from illnesses and helps alleviate potential pain. It also improves mental health by reducing the risks of stress, depression, and dementia—factors that significantly impact overall health [21,28,29,30,31,32]. Supporting the development and enhancement of pedestrian infrastructure, which solves issues from the societal to the individual level, is a key factor in achieving these goals [33,34,35,36].

To support the goal of mitigating global warming. The researchers conducted an additional literature review and found that physical components, including the built environment, green spaces, and surrounding elements, play a significant role in pedestrian development [21,37].

Although the benefits of supporting the development of pedestrian systems are well recognized as contributing toward achieving the goals, various factors that influence walking have also been identified in previous studies; nevertheless, climatic conditions remain a crucial factor affecting people’s willingness to walk [38,39,40]. Furthermore, in a tropical humid region with a hot climate, the climate crisis imposes stress that discourages people from walking. Moreover, people tend to choose shaded areas or walk within the built environment more often [41].

A recent study also indicated the need for further research in the future [42,43,44], due to the lack of consideration of climatic factors in the assessment of the pedestrian environment. In other words, commonly used pedestrian assessment tools often do not incorporate key factors relevant to tropical humid regions, such as heat, rainfall, or seasonal variations, which may result in designs that do not align with actual user behaviors [42]. This also includes the lack of data and design guidelines appropriate for the tropical humid context. Design in tropical humid regions still lacks fundamental scientific data, such as the physical characteristics of cities under humid hot climates, which poses a significant barrier to developing a built environment that meets local needs [43]. Importantly, there is also a lack of in-depth studies on the built environment and walking behavior in tropical humid regions, particularly from case studies in Bangkok. It has been found that there is less research on the relationship between residential neighborhood design, walkability, and human behavior in hot and humid climates [44]. These issues underscore the fact that, within the tropical humid context, there is still less research on the support and development of pedestrian infrastructure aimed at achieving the objectives.

At the same time, several tropical countries that have recognized and emphasized the need to prepare for the challenges of a boiling world are taking action [33,34,35,36]. Singapore is one such country, where these locations have been selected based on their frequent mention in various research studies. These locations encompass issues related to the promotion of walkability, the importance of attracting people, and the historical significance of the areas [45,46,47,48]. The locations are Marina Bay, Orchard Road, Boat Quay, and Chinatown, which serve as key case studies in this research.

Therefore, in order to mitigate global warming, reducing greenhouse gas emissions from traffic is of significant importance. This research therefore aims to promote walking, recognizing that while sidewalk design influences the desire to walk, the hot and humid climate discourages pedestrian activity. This research therefore focuses on identifying sidewalk design strategies that support the desire to walk in a tropical humid climate. Through a review of publications, field surveys, data analysis, and synthesis, this study examines sidewalk or built environment design approaches that support the desire to walk in a tropical humid climate. This leads to the first research question: What are the characteristics of walkable sidewalks in tropical humid urban areas? And since green spaces influence the desire to walk, this leads to the second research question: What are the design guidelines for sidewalks related to green spaces in tropical humid areas that effectively encourage people to walk?

2. Literature

Based on this research, which focuses on identifying sidewalk or built environment design strategies to support the desire to walk in a tropical humid climate, a systematic literature review was conducted to help find the answers.

2.1. Sidewalk Design That Encourage Walking

From the literature review on sidewalk design guidelines that promote walkability in tropical humid climates, it has been found that there is still a lack of comprehensive studies in this area. We conducted a literature review focusing on sidewalk components that incorporate green spaces as integral elements which encourage walking and have the potential to mitigate the impacts of global warming. The researchers identified a total of five studies that highlight the importance of sidewalks and their components, which tend to encourage pedestrian activity. These studies were sourced from various academic databases [33,34,35,36,49].

In this study, only physical elements or those perceivable through visual sensory perception were selected for further analysis. Further studies have indicated that visual perception is often regarded as the most significant sensory modality in architectural design [50,51].

From the review, a total of five studies were identified that explored design elements which encourage walking. These studies revealed seven key components: form elements, space elements, movement elements, functional elements, emotional elements, object elements, and view elements [33,34,35,36,49]. The details of each component are as follows:

The first component, form elements, was found in the research to most frequently address the topics of infrastructure and traffic, particularly concerning pedestrian infrastructure [35,49]. Emphasis is placed on traffic safety [34,35,36,49], as lower traffic volumes [35,49] and reduced vehicle speed can positively influence walking behavior. In addition to safety considerations, aspects such as universal design and public transport connectivity [49] also play a role in encouraging walking.

The next topic is naturalness, which includes discussions on natural areas, focusing on aspects such as the number of trees [34], the presence of shade [33,34,36,49], and the presence of litter [34]. These factors contribute to the perception of naturalness in the environment and influence the desire to walk.

Another equally important topic is physical form and design [33,34,35,36,49], which includes the system of the street [33], and the character of the street or road [49], as well as open-ended design [33] and streetscape design [33].

The final topic under form elements is route characteristics, which refers to street connectivity [34,35,36,49], a factor that influences people’s walking behavior.

The second component, space elements, includes site planning considerations on a human scale, retrofitting older communities, and ordering for access [33]. These aspects are found under the topic of route conditions within urban spaces and parks [33,36,49].

This topic discusses the presence of sidewalks [34,49], as well as the type of ground surface [34], noting that different surface types affect walking behavior. Additionally, the pavement width [34,36] and slope [33,34,35] are also influential factors. Another key point is the role of built environment variables, such as density, diversity, distance, connectivity, and design, which have been found to have statistically significant associations with pedestrian volume [34,35,36].

The third component, movement elements, is related to accessibility, walking routes, perceived safety, comfort, and various factors influencing movement in urban space [33,34,35,49].

The first topic, which includes the greatest number of subcomponents, is comfortability and pleasurability. This encompasses the presence of shading or cover [36], security [33,34,35,36,49], activity [33,34,35,36,49], and low pollution [36]. These factors all influence people’s preference to walk [36] and their overall pleasure [33,36] while walking.

The next topic is route safety, which discusses vehicle traffic flow [34] relating to safety, crime prevention, dense traffic signals, and main roads. In addition, signage [34,49] and the number of crosswalks [34] are all positively associated with walkability and aesthetically pleasing scenery with leisure-time walking [34,35,49].

The issue of surroundings and activities is also important, as recreational activities encourage people to access parks and leisure facilities, thereby encouraging walking. Key elements identified in this context include people walking or staying [49], experienced safety [35,49], destinations [33,34,35,49], and wayfinding or directional signage [33,49].

The final topic in the movement elements component is convenience, which emphasizes cleanliness (clean) [34,36,49], smooth walking surfaces (smooth) [36], and the absence of obstacles (no obstacle) [36].

The fourth component, functional elements, relates to function and usability as well as the urban infrastructure that encourages walking behavior. The first topic in this component is urbanity, which refers to encouraging more people to walk and contributing to overall design success [33,34,35,36,49].

In the context of the importance of urbanity, the orientation of buildings [49] is linked to aspects such as scale [34,35,36,49], block sizes [49], and urban structure [49], all of which are significant. Additionally, density [34,35,36,49], proximity [34,35,49], connectedness [33,34,35,36,49], and permeability [49] are also key factors in urban usability. Furthermore, small details can influence people’s walking choices, such as urban spaces and parks [49], green areas [33,34,35,49], parking lots [33,49], and street furniture [33,34,35,49].

Next, on the topic of usage, it is noted that usage is dominated by a single function (domination by function) [33], aiming to provide comfort and safety [33,34,35], focusing on mixed land use (land use mix) [33,35] to promote activity variations and diversity [33].

The integration of transportation systems to support usability must consider the number of bus stops and bike spots [34] and the distance to the subway station [34], as well as the presence of bike lanes, which is also important [34].

The final topic of the functional elements is the network, which involves route connectivity [33] as well as the pedestrian network [35,49], both related to people’s usage choices.

The fifth component, emotional elements, concerns the emotional impact, including vibrancy [36,49] and social interactions characterized by ambiguity or openness to multiple interpretations [33], which bring to a walkable environment.

Research has found that attractiveness is an important issue, where the number of shops and services [33] as well as the number of tourist establishments [33] may influence people’s decisions.

Additionally, the proportion of windows facing the street, the proportion of active street frontage, and the number of street furniture elements (pedestrian counts after controlling for density and other built environmental variables) also affect attractiveness in terms of people’s desire to use the space [33,35].

Finally, having a sense of community is positively associated with walking for transport [33,35].

The sixth component, object elements, refers to tangible objects related to architecture, as they are associated with building facades, which may influence people’s walking choices [33,36,49].

The seventh component, view elements, relates to visual simplicity—the processing of visual information that encourages walking. Findings indicate that designs or elements that are simple, uncomplicated, and free from excessive visual distractions positively influence the desire to walk [33].

In this study, we specifically focused on elements related to green spaces. Furthermore, a review of the literature revealed an important factor in encouraging pedestrian travel points in the role of sidewalk designs that incorporate green spaces, which play a significant role in heat reduction, contributes to achieving the goal of mitigating global warming, and significantly encourages people to choose pedestrian travel [52,53,54,55]. Recent studies have also indicated the need for further research [34]. This has led to a study focused on the design of the built environment for pedestrian pathways in green cities.

2.2. Design Guidelines for the Built Environment of Sidewalks in Green Cities

Since green spaces influence the design guidelines of sidewalks or the built environment to encourage walkability, we conducted further studies on the design of the built environment for sidewalks in green cities with the aim of encouraging pedestrian activity significantly.

From a review of 13 previous studies concerning the importance and design guidelines of the built environment for sidewalks in green cities, it was found that the elements that promote walkability can be categorized into 13 main groups, as follows:

The form elements include natural form [45,56,57] and natural geometry [47], along with free form [48] design that avoids rigid straight lines and harsh angles [45,58]. They also incorporate biomorphic [59,60] features and biophilic urban planning [45,46,61,62]. In addition, biophilic elements are organized hierarchically across different scales, from region to building, and vary in size, distance, and function [63,64]. This component also considers the proportion between green space and built-up area [65], the density of vegetation within green space [66,67], and the integration of green buildings [68,69,70].

The space elements include a connection to nature [46,71,72], providing exposure to it [46,73], and integrating forms that enhance ecological functions [70,74]. They are also associated with attention, mood, and physical activity [46,75,76], and positively intervene in human health [77,78]. Space offers activity areas [46], communal spaces, and cultural facilities [79], along with essential amenities [80,81]. It emphasizes visual prospects, highlighting horizons, movement, and potential sources of danger [81]. Refuge is provided through comfortable and nurturing interiors [74], fostering a strong connection to the identity or sense of place [81,82,83]. Finally, the complexity of spatial design enriches experiences and evokes past connections with nature [84,85].

The movement elements encompass mobility between spaces through entry and exit [45,73], facilitating easy relocation to access more nature [45,73]. They also involve transport connectivity [62,86], ensuring smooth access and approach to green spaces [82,87]. The time it takes to reach the nearest green space [56,88] and the proximity to nature from residential areas are also key factors in enhancing movement within the environment [89,90].

The light elements include natural light [57,91,92], which brightens spaces and connects the interior with the outside. Dynamic natural light [57,85,92] varies throughout the day, bringing life to the environment. Daylight [57,92,93] boosts well-being, while daylit interior spaces [70,73,92] create healthy, vibrant areas. The play of shadows [57,85] adds depth and visual interest to the space.

The color elements feature natural colors [57,94], which harmonize with the environment, and earth tones like browns, greens, and blues [57,71,94] that create a calming atmosphere. While bright colors can energize, they may also become fatiguing and distracting [57,71] when overused.

The material elements include natural materials [57,71,92] that blend seamlessly with the environment, as well as natural fabrics, furnishings, and leather used in interior design [71,92,95]. These elements foster a connection with nature [57,96] and between people and nature [57,96]. Materials that age with time [57,71,85] create a historical sense, while natural patterns [57,71,85,97] and biomorphic patterns add visual richness [92,98]. The complexity and order found in natural patterns enhance the overall aesthetic and ambiance [84,98].

The object elements include various elements that enhance the relationship between urban spaces and nature [57,72,99]. These include ornaments [95,100] that complement the environment, as well as images of nature, which can be expressed through paintings, photos, sculptures, murals, and videos [57,71]. Green infrastructure [68,72,101,102] plays a key role, along with stormwater management based on the sponge city concept [103,104,105]. Urban ecosystem services contribute to protecting both human health and the environment [103,104,105]. Additionally, land use and habitat protection [70,106,107] are essential for biodiversity conservation. Interconnecting green space networks [108,109] helps mitigate fragmentation, while infrastructure designed to alleviate climate change [101,108,109,110] and hybrid facilities [111] further support sustainable urban development.

The view elements include plants, indoor plants, vegetation, and greenery [68,92], and the incorporation of plants into buildings [57,92,100]. They feature animals and wildlife [57,70], as well as water [57,112] and wetlands [57,113]. In addition, they consider environment [72,114,115,116], open space [85,117,118], and agriculture [57,119,120]. They include woodland [45], meadow [85,113,121], and forest [85], together with corridor [57,70] and streetscapes [62,85,114]. Courtyard [122,123,124], urban green space [94,125], and urban habitat spaces [57,70] are also included, along with urban farming [57,119] and local green elements [68,87,102]. Moreover, they address geography [70,126], biodiversity [70,127], ecosystem [70,116,128], and natural resource [72,114].

The sound elements focus on the soothing and natural sound of water, which enhances the environment by adding a calming auditory element to the space. [112]

The weather elements encompass various elements, including air [57,92] quality, pollution [57,87] levels, ventilation [57,92], and the overall of weather [70,129] and climate [57,68,114] conditions. They also consider temperature [57,130] regulation, stormwater [57,131,132] management, heat [61,130], and thermal regulation [92,130,133], all of which contribute to creating a comfortable and sustainable environment.

The sense elements involve several elements, including the experience of the environment [134,135,136], visual sensory input [137,138], and non-visual sensory experiences such as hearing, smelling, and touching [138,139]. They also include awareness [140], mental engagement [79,96,141], and individual perception [63,142], all of which contribute to how people perceive and interact with their surroundings.

The emotion elements include various aspects that influence feelings and moods. These include emotions [117,143], positive moods associated with exposure to urban green spaces [46,144], and increased attention where green elements are well-maintained [145,146]. They also encompass the attractiveness [147,148], revitalization [82,149,150], and vibrancy that green spaces bring [46], as well as their potential for helping individuals recuperate [45]. This component also addresses feelings of risk or peril [46,73], mystery [85], stress [151,152,153], comfort [154], relaxation [155,156], and friendliness [157], all of which contribute to the emotional impact of the environment.

The function elements include a variety of aspects that support the overall effectiveness of spaces. These encompass sustainability [57,73,87] and ecological considerations [73,158], technological integration [159,160], and management practices aimed at maintaining and restoring environments [73,161]. They also focus on improving both the psychological and physical health of the local population [46,162], supporting health and wellness [163,164], and enhancing the overall quality of life [165,166]. This component emphasizes multifunctionality [167,168,169], aesthetics [96,170], resilience [73,171], flexibility [45,68], and performance [172,173], while also considering the efficient utilization of resources [160,171]. Additionally, it addresses urbanization [70,99], the reduction of energy consumption [130,174], and the principles of biomimicry [175,176], promoting a harmonious relationship between nature and design.

From the review of all 13 studies, the elements that serve as design guidelines to promote walkability can be classified into 13 main components: Form Component, Space Component, Movement Component, Light Component, Color Component, Material Component, Object Component, View Component, Sound Component, Weather Component, Sense Component, Emotion Component, and Function Component. All of these components significantly influence the design of the built environment for sidewalks in green cities.

3. Materials and Methods

3.1. Case Study

Singapore, as a tropical humid country, maintains a relatively constant average temperature of 23–33 °C [177] (see Appendix D) and an awareness to prepare for global boiling [178,179,180,181]. This is directly related to this study, as we seek a design approach for sidewalk or built environment design to support the desire to walk in a tropical humid climate.

Singapore is also a country known for its walkability, and has a vision to prioritize an environment that supports well-being from the individual level to social development. This makes it suitable to be studied as an example of sidewalk design. Therefore, this study was conducted to gather data in support of this aim, leading to our results.

3.2. Data Collection

This study uses Singapore as a case study for tropical humid countries that face challenges in pedestrian mobility. This research includes a survey, documentation, and analysis of urban design approaches that promote walkability in tropical humid climates. Data was collected from the general public through an online questionnaire using Google Forms. The questionnaire was distributed via social media platforms. In choosing Google Forms, the authors considered previous research indicating that it is an accessible and widely used tool for reaching a broad audience [182,183].

The data collection period lasted five days, from 23 March 2025 to 27 March 2025, during which a total of 39 respondents completed the questionnaire. A minimum sample size of 30 participants was set, based on previous research, to ensure an effective dataset [184,185]. All respondents to the questionnaire were residents of tropical humid countries. The questionnaire included basic respondent information as outlined in Appendix B, such as gender, age, current occupation, and income (see Appendix B).

Therefore, the questionnaire yielded 39 valid responses deemed appropriate as data from the general public. The responses were recorded in a Google Sheet, organized chronologically by submission time, and accessible only to the researchers, research assistants, and data coders.

3.2.1. Procedure

At this stage, data collected from the survey was compiled and analyzed. The resulting dataset serves as a subset for further in-depth analysis, which is of significant importance [186]. The in-depth analysis is presented in Section 3.3.2 (part 2) and the results are detailed in Section 4.3.

(1)

Site survey implementation

In the initial phase, field surveys and photographic documentation were conducted in areas recognized for having environments that encourage walking in Singapore over a period of five days, from 16 November 2024 to 19 November 2024, including Marina Bay, Orchard Road, Boat Quay, and Chinatown (see in Figure 1)—these locations were selected based on their frequent mention in various research studies. These studies encompass aspects of promoting walkability, the significance of attracting people, as well as the historical roles of the areas [187,188,189,190]. The authors conducted photographic documentation with careful consideration of urban design elements that facilitate pedestrians, as discussed in Section 2.

In the second phase, the photographs obtained from the survey were collected and systematically selected. Based on the promoting walkability criteria outlined in Section 2. The screening process was conducted using a triangulation method involving multiple researchers [191] to ensure the consistency and reliability of the data. From an initial total of 66 photographs, after applying the selection criteria and a reflective review by multiple researchers, 39 images remained for further analysis.

(2)

Data analysis procedures

The analysis of the data was carried out using two primary methodologies, as follows:

The first approach involved image decoding through manual annotation using Supervisely versions 6.12.33. This platform is employed for image segmentation and object detection tasks to differentiate and identify urban design elements that promote walkability.

The choice of the Supervisely platform was based not only on its user-friendly interface but also on its ability to deliver accurate results. It is also a platform widely utilized for image segmentation and object detection, as referenced in numerous studies [192,193,194].

The second approach involved assessing walkability through questionnaires. Data collection was conducted using a questionnaire adapted from studies related to the assessment of walkability [195] that was adapted to suit the context of the present study. The questionnaire was administered in conjunction with the presentation of 39 images which were selected through the prior screening process. The questionnaire comprised fundamental respondent information, including gender, age, current occupation, income, and questions related to walking, as follows:

-

Do the presented images encourage you to walk (on the sidewalks)?

-

How much do these images influence your motivation to walk more or less often?

-

Do the images inspire you to recommend others to walk (on the sidewalks)?

3.3. Data Analysis

Based on the analysis conducted through the two main approaches to obtain results for research questions in Section 1, the following conclusions were drawn.

3.3.1. Summary of Results Using Descriptive Statistics

To obtain results for Question 1 (What are the characteristics of walkable sidewalks in tropical humid urban areas?), the researchers began by decoding the images using the Supervisely platform, as described in Section 3.2.1. The researchers were able to decode the analyzed images. Based on the seven promoting walkability elements established in Section 2: form elements, space elements, movement elements, functional elements, emotional elements, object elements, and view elements.

The calculations were performed using image segmentation and object detection via the Supervisely platform to distinguish and identify the urban design elements that promote walkability. Keywords were used to assist in capturing the walkability-promoting elements from all 39 images from the site survey. After image capture was completed, the system analyzed the data to quantify the presence of keywords in each image. The resulting values enable the identification of characteristics of the built environment of sidewalks in tropical humid areas.

3.3.2. Summary of Results Using Correlation Analysis to Determine Consistency

To obtain results for Question 2 (What are the design guidelines for sidewalks related to green spaces in tropical humid areas that effectively encourage people to walk?), the researchers needed to conduct the analysis concurrently with the summary of results, using basic statistics to examine the relationships among all elements and determine whether green spaces are associated with sidewalk design. The procedure was carried out as follows.

(1)

Questionnaire decoding.

Based on the questionnaire data collection as described in the second approach of the data analysis procedure. After obtaining responses from respondents, statistical data has been compiled. The researchers utilized the respondents’ answers that related to walking. These multiple-choice questions were converted into numerical scores on a Likert scale, where ‘Most’ = 5, ‘Much’ = 4, ‘Moderate’ = 3, ‘Little’ = 2, and ‘Least’ = 1, resulting in the following table (see in

Table 1. Walking-related questions in online survey.

Questions	Least	Little	Moderate	Much	Most
Do the presented images encourage you to walk (on the sidewalks)?	☐	☐	☐	☐	☐
How much do these images influence your motivation to walk more or less often?	☐	☐	☐	☐	☐
Do the images inspire you to recommend others to walk (on the sidewalks)?	☐	☐	☐	☐	☐

):

Data decoding began at the individual level, with three questions associated with each image (although the question does not explicitly mention the tropical humid climate, the responses have led to a dataset for significant consideration of pedestrian walkway design characteristics in tropical humid areas). The researchers disaggregated the same question across all images. This resulted in three distinct sets of responses obtained from all questionnaire participants. Subsequently, by compiling the three sets of responses from all participants, the mode of each dataset could be calculated at the aggregate level. This enabled the identification of the extent to which each image encouraged the desire to walk, to return for another walk, and to recommend the location to others.

(2)

To obtain results for Question 2

By integrating the data from basic statistical analysis and correlation analysis to identify how pedestrian design strategies with green spaces influence walking desirability in tropical climates, through a concurrent consideration of the questionnaire results. This facilitates the differentiation of how the various built environment components of pedestrians with green spaces influence interest in walking (Figure 2).

4. Results

To obtain results for research objectives, an investigation was conducted to explore pedestrian design strategies or built environment approaches that encourage walking desirability in tropical climates. Based on the Singapore case study, two survey methods were employed; the first one was a summary of results using descriptive statistics as in Section 3.3.1, to obtain results for Question 1. The second method involved summarizing results through correlation analysis to assess consistency, as in Section 3.3.2, to obtain results for Question 2. The study results are as follows.

4.1. Study Results Reporting the Observed Characteristics from Image Decoding

To obtain results for the objective related to Question 1, by using the Supervisely platform versions 6.12.33 as described in Section 3.2.1., seven promoting walkability design elements were considered, as defined in Section 2 and discussed in Section 3.3.1. The authors obtained a statistical dataset from the image decoding process, presented as percentages indicating the prevalence of each element, compiled in a Google Sheet (see Appendix A).

Observed Characteristics from Image Decoding at Pedestrian-Friendly Locations in Singapore

Based on field surveys and photographic documentation conducted in areas recognized for their pedestrian-friendly environments in Singapore, the authors classified the sites into four main locations. The survey yielded valuable data concerning promoting walkability elements that incorporate greenery as a key component. These elements can be categorized as follows:

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Boat Quay

Starting from Boat Quay, an area with significant historical importance, part of which is the old buildings that serve as important historical evidence. These buildings have been adaptively reused for commercial purposes, which has helped make the area more attractive and encourages people to visit and walk in this location [189]. This makes Boat Quay interesting and attracts people through certain elements that promote walkability.

Through the survey and data collection, the process led to the decoding of images by calculating the average values of each element in Boat Quay. It was found that natural light was the most prominent element in the view (72% of the average image values in Boat Quay). It was also observed that trees, particularly large trees, were the second most prominent element in the space (17% of the average image values in Boat Quay). Next was the sidewalk in the emotional element (14% of the average value), followed by other elements in the functional elements (11% of the average value). The connect to natural element was highest in the space elements (10% of the average value), along with the natural shape in the form elements (9% of the average value).

Additionally, some elements that can still be observed in the images from Boat Quay include transitional spaces in the space elements (7% of the average value), order and complexity in the space elements (6% of the average value), environmental features in the emotional elements (6% of the average value), and shade and shadow in the view elements (5% of the average value).

Additionally, there are elements that can be observed in some images or are found in smaller quantities, such as mobility in the movement elements (4% of the average value), natural form in the form elements (3% of the average value), plants such as shrubs in the space elements (3% of the average value), public transportation facilities in the functional elements (1% of the average value), natural materials in the emotional elements (1% of the average value), water surfaces in the space elements (1% of the average value), overhead plane in the form elements (1% of the average value), and natural patterns in the form elements (1% of the average value).

The survey in Boat Quay found that natural light was the most prominent element among the view elements. It was noted in 72% of the average image values in Boat Quay, being present in many of the images collected during the survey, with a high percentage to the average of each image (see in

Table 2. Average values of elements found from image decoding in Boat Quay.

Boat Quay Pic	Natural Light	Tree	Side Walk	Other	Connect to Natural	Natural Shape	Transitional Spaces	Order and Complexity	Environmental Feature	Shade and Shadow	Mobility	Natural Form	plants	Public Transportation Facility	Natural Materials	Water	Overhead Plane	Natural Pattern
PIC1	0.07	0.62	0.00	0.00	0.00	0.00	0.20	0.00	0.00	0.21	0.01	0.00	0.13	0.00	0.00	0.00	0.00	0.00
PIC2	1.00	0.19	0.10	0.00	0.00	0.00	0.00	0.03	0.03	0.00	0.01	0.00	0.06	0.00	0.00	0.05	0.00	0.10
PIC3	1.00	0.14	0.26	0.00	0.00	0.00	0.00	0.00	0.00	0.07	0.07	0.00	0.08	0.00	0.00	0.07	0.00	0.00
PIC4	1.00	0.23	0.56	0.09	0.00	0.00	0.27	0.00	0.00	0.08	0.18	0.00	0.00	0.00	0.00	0.00	0.02	0.00
PIC5	1.00	0.13	0.30	0.08	0.00	0.00	0.22	0.00	0.00	0.07	0.00	0.00	0.05	0.00	0.00	0.00	0.02	0.00
PIC6	1.00	0.05	0.15	0.00	0.00	0.00	0.08	0.00	0.00	0.02	0.07	0.00	0.00	0.00	0.00	0.00	0.00	0.00
PIC7	1.00	0.04	0.27	0.00	0.00	0.00	0.18	0.00	0.00	0.00	0.04	0.00	0.00	0.00	0.00	0.00	0.00	0.00
PIC8	1.00	0.07	0.11	0.00	0.00	0.00	0.04	0.00	0.00	0.08	0.01	0.00	0.00	0.00	0.00	0.00	0.05	0.00
PIC9	0.16	0.08	0.00	0.20	0.29	0.19	0.00	0.17	0.19	0.00	0.05	0.00	0.02	0.01	0.00	0.00	0.00	0.00
PIC10	0.52	0.28	0.00	0.18	0.18	0.14	0.00	0.09	0.09	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
PIC11	0.00	0.12	0.00	0.24	0.30	0.26	0.00	0.22	0.21	0.11	0.00	0.00	0.02	0.09	0.00	0.00	0.00	0.00
PIC12	0.28	0.14	0.00	0.21	0.26	0.19	0.00	0.13	0.13	0.05	0.00	0.00	0.02	0.04	0.00	0.00	0.00	0.00
PIC13	1.00	0.00	0.00	0.44	0.33	0.46	0.00	0.15	0.15	0.00	0.07	0.48	0.05	0.00	0.10	0.00	0.00	0.00
PIC14	1.00	0.31	0.23	0.07	0.04	0.00	0.03	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.02	0.00	0.00
MEAN	0.72	0.17	0.14	0.11	0.10	0.09	0.07	0.06	0.06	0.05	0.04	0.03	0.03	0.01	0.01	0.01	0.01	0.01

).

-

Chinatown

Next, in Chinatown, which is one of the historically significant locations in Singapore and holds importance as a tourist attraction [188], various elements were featured that promote walkability, including natural light in the view elements, which was found in large amounts (55% of the average image values in Chinatown).

It also includes other elements that were found in moderate amounts, such as trees—particularly large trees—in the space elements, which were the second most prominent (25% of the average image values in Chinatown), the sidewalk in the emotional elements (22% of the average image values), and natural materials in the emotional elements (14% of the average image values), environmental features in the emotional elements (12% of the average image values), and other elements in the functional elements (11% of the average image values).

Additionally, there are elements that were found in some images or in smaller amounts, such as overhead plane in the form elements (7% of the average image values), plants such as shrubs in the space elements (6% of the average image values), shade and shadow in the view elements (5% of the average image values), transitional spaces in the space elements (3% of the average image values), mobility in the movement elements (3% of the average image values), public transportation facilities in the functional elements (2% of the average image values), and unnatural materials in the emotional elements (1% of the average image values).

The survey in Chinatown found that natural light was the most prominent element among the view elements. It accounted for 55% of the average image values in Chinatown, being present in many of the images collected during the survey, with a high percentage to the average of each image (see in

Table 3. Average values of elements found from image decoding in Chinatown.

Chinatown Pic	Natural Light	Tree	Color	Natural Materials	Environmental Feature	Other	Overhead Plane	Plants	Shade and Shadow	Transitional Spaces	Mobility	Public Transportation Facility	Unnatural Materials
PIC1	0.27	0.11	0.26	0.00	0.15	0.22	0.05	0.02	0.02	0.00	0.03	0.00	0.00
PIC2	0.18	0.06	0.21	0.00	0.42	0.00	0.00	0.00	0.02	0.00	0.04	0.00	0.20
PIC3	0.25	0.27	0.03	0.02	0.23	0.08	0.05	0.02	0.21	0.14	0.04	0.00	0.00
PIC4	0.20	0.31	0.00	0.21	0.02	0.07	0.00	0.04	0.21	0.00	0.01	0.00	0.00
PIC5	1.00	0.09	0.12	0.00	0.00	0.05	0.00	0.05	0.00	0.21	0.03	0.00	0.00
PIC6	1.00	0.16	0.00	0.03	0.00	0.09	0.00	0.03	0.00	0.00	0.02	0.08	0.00
PIC7	1.00	0.20	0.00	0.00	0.00	0.06	0.00	0.08	0.18	0.01	0.09	0.00	0.00
PIC8	1.00	0.47	0.12	0.00	0.00	0.18	0.00	0.09	0.00	0.00	0.01	0.09	0.00
PIC9	0.19	0.01	0.23	0.87	0.06	0.00	0.39	0.02	0.02	0.00	0.00	0.00	0.00
PIC10	0.66	0.63	0.19	0.19	0.33	0.00	0.00	0.00	0.00	0.00	0.12	0.03	0.00
PIC11	0.55	0.33	0.52	0.11	0.03	0.16	0.19	0.14	0.00	0.00	0.02	0.01	0.00
PIC12	0.53	0.18	0.78	0.24	0.01	0.17	0.14	0.11	0.00	0.00	0.01	0.04	0.00
PIC13	0.47	0.22	0.31	0.15	0.28	0.00	0.07	0.07	0.00	0.00	0.01	0.03	0.00
PIC14	0.35	0.54	0.25	0.10	0.08	0.45	0.14	0.14	0.10	0.00	0.01	0.00	0.00
MEAN	0.55	0.25	0.22	0.14	0.12	0.11	0.07	0.06	0.05	0.03	0.03	0.02	0.01

).

-

Orchard Road

Orchard Road is another important street in Singapore, renowned as the country’s premier shopping street, and it has the highest pedestrian traffic among the various pedestrian networks [187]. The researchers found various elements that promote walkability, including natural light in the view elements, which was the most prominent (63% of the average image values in Orchard Road). The second most prominent element was the sidewalk in the emotional elements (26% of the average image values) in Orchard Road.

Additionally, there were sub-elements within the space elements that influence walkability, such as trees, particularly large trees (18% of the average image values), and plants such as shrubs (9% of the average image values).

Additionally, there are elements that were found in some images or in smaller amounts, such as mobility in the movement elements (4% of the average image values), transitional spaces in the space elements (4% of the average image values), public transportation facilities in the functional elements (3% of the average image values), natural materials in the emotional elements (3% of the average image values), natural color in the emotional elements (2% of the average image values), and overhead plane in the form elements (2% of the average image values).

Lastly, elements that were found in very small amounts were order and complexity in the space elements (only 1% of the average image values), environmental features in the emotional elements (only 1% of the average image values), and other elements in the functional elements (only 1% of the average image values).

The survey in Orchard Road found that natural light was the most prominent element among the view elements. It accounted for 63% of the average image values in Orchard Road, being present in many of the images collected during the survey, with a high percentage to the average of each image (see in

Table 4. Average values of elements found from image decoding in Orchard Road.

Orchard road Pic	Natural Light	Color	Tree	Plants	Mobility	Transitional Spaces	Public Transportation Facility	Natural Materials	Natural Color	Overhead Plane	Order and Complexity	Environmental Feature	Other
PIC1	0.54	0.08	0.12	0.09	0.03	0.00	0.00	0.00	0.00	0.00	0.00	0.09	0.02
PIC2	0.69	0.00	0.11	0.27	0.05	0.00	0.17	0.00	0.00	0.03	0.06	0.00	0.05
PIC3	0.65	0.22	0.17	0.22	0.04	0.00	0.05	0.00	0.00	0.00	0.00	0.00	0.00
PIC4	0.28	0.61	0.07	0.00	0.04	0.25	0.00	0.00	0.00	0.03	0.00	0.00	0.00
PIC5	1.00	0.31	0.33	0.02	0.09	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
PIC6	0.49	0.13	0.02	0.04	0.01	0.04	0.00	0.17	0.14	0.06	0.00	0.00	0.00
PIC7	0.79	0.49	0.43	0.02	0.02	0.00	0.00	0.07	0.00	0.00	0.00	0.00	0.00
MEAN	0.63	0.26	0.18	0.09	0.04	0.04	0.03	0.03	0.02	0.02	0.01	0.01	0.01

).

-

Marina Bay

The final location is Marina Bay, which is a significant site in Singapore and one of the places with high tourist traffic [190]. It is also an area that has been managed with measures or given importance to green spaces in line with Singapore’s green city development concept.

Therefore, it is a place worth exploring, where the researchers found the following elements that promote walkability: Natural light in the view elements, which was found in large amounts (68% of the average image values in Marina Bay). Next, trees, particularly large trees, in the space elements were the second most prominent (27% of the average image values in Marina Bay). The next most prominent element was other in the functional elements (10% of the average image values).

Additionally, there were elements that were found in some images or in smaller amounts, such as shade and shadow in the view elements (6% of the average image values), plants such as shrubs in the space elements (6% of the average image values), sidewalk in the emotional elements (5% of the average image values), transitional spaces in the space elements (5% of the average image values), mobility in the movement elements (4% of the average image values), and water surfaces in the space elements (3% of the average image values).

Finally, elements that were found in very small amounts include natural shape in the form elements (1% of the average image values) and order and complexity in the space elements (1% of the average image values).

From the survey conducted in Marina Bay, it was found that natural light among the view elements was the most prominent element. It accounted for 68% of the average image values in Marina Bay, appearing in many of the surveyed images with a high percentage to the average of each image (see in

Table 5. Average values of elements found from image decoding in Marina Bay.

Orchard Road Pic	Natural Light	Tree	Other	Shade and Shadow	Plants	Color	Transitional Spaces	Mobility	Water	Natural Shape	Order and Complexity
PIC1	1.00	0.10	0.08	0.00	0.09	0.00	0.00	0.08	0.02	0.00	0.01
PIC2	1.00	0.01	0.17	0.00	0.04	0.19	0.18	0.01	0.09	0.03	0.03
PIC3	0.27	0.50	0.05	0.05	0.05	0.00	0.00	0.03	0.00	0.00	0.00
PIC4	0.45	0.46	0.11	0.18	0.07	0.00	0.00	0.03	0.00	0.00	0.00
MEAN	0.68	0.27	0.10	0.06	0.06	0.05	0.05	0.04	0.03	0.01	0.01

).

Finally, from the field surveys and photography from areas recognized for having walkable environments in Singapore—Boat Quay, Chinatown, Orchard Road, and Marina Bay—the images from each location were classified and decoded. This process revealed various elements that promote walkability. It was found that each location shared similar components, as illustrated in Figure 3.

4.2. Findings from the Correlation Analysis to Identify Patterns of Consistency

To obtain results for research objective related to Research Question 2, the study investigated how pedestrian walkway design strategies with green spaces encourage walkability in tropical climates, using Singapore as a case study. This was conducted through an online questionnaire distributed via social media platforms, employing a quantitative survey research approach. The results from the data collection and analysis are presented as follows.

Data Analysis Results

Regarding the dataset of questions related to walking mentioned in Section 3.2.1 Procedure, under item (2) Data Analysis Procedures, the assessment of walkability was conducted through a questionnaire. All respondents to the questionnaire reside in tropical humid countries.

All validated data were converted into numerical values, with ‘1’ representing ‘least’, ‘2’ for ‘little’, ‘3’ for ‘moderate’, ’4’ for ‘much’ and ‘5’ indicating ‘most’, as reported by the respondents. The data were recorded in Google Sheets and subsequently processed statistically by calculating the mode (see Appendix C).

4.3. Results for Research Question 2: What Are the Design Guidelines for Sidewalks Related to Green Spaces in Tropical Humid Areas That Effectively Encourage People to Walk?

Upon obtaining the statistical dataset, the researchers proceeded according to the methodology described in Section 3.3.2, under list label (2), for deriving the results of Research Question 2. Data from two sources—

Table A1. Statistical data obtained from image decoding.

	Form	Space	Movement	Functional	Emotional	Object	View
PIC1	0.01345	0.0218	0.0167	0.000233	0.08272	0	0.14655
PIC2	0	0.0102	0.02025	0.001133	0.16538	0	0.09825
PIC3	0.011825	0.070967	0.01875	0.045067	0.05662	0	0.2339
PIC4	0	0.0582	0.0053	0.000633	0.0462	0	0.2058
PIC5	0	0.058183	0.0125	0.0684	0.02306	0	0.5
PIC6	0	0.031717	0.008	0.025633	0.00546	0	0.5
PIC7	0	0.15885	0.00375	0.067367	0	0	0.1393
PIC8	0.02535	0.05605	0.00635	0	0.02518	0	0.5
PIC9	0	0.04805	0.0467	0.004633	0	0	0.588
PIC10	0	0.049633	0.0374	0.000467	0.05178	0	0.5347
PIC11	0.0039	0.0829	0.09055	0.0894	0.11168	0	0.5383
PIC12	0.00435	0.066917	0	0.0726	0.05926	0	0.5355
PIC13	0	0.020683	0.03415	0.026	0.029	0	0.50995
PIC14	0	0.037883	0.02095	0.059567	0.05466	0	0.5
PIC15	0.012825	0.0177	0.0042	0.013467	0.02136	0	0.53795
PIC16	0.04835	0.09405	0.02255	0.0104	0.03746	0.0172	0.07845
PIC17	0.03495	0.092933	0	0	0.01742	0	0.2606
PIC18	0.064625	0.109367	0	0.031067	0.04264	0	0.05485
PIC19	0.046375	0.08975	0	0.013667	0.02698	0	0.1644
PIC20	0.23425	0.088867	0.0339	0	0.05164	0	0.5
PIC21	0	0.066217	0.0005	0.010867	0.0463	0	0.5
PIC22	0	0.036217	0.0423	0	0	0	0.5
PIC23	0.007775	0.058533	0.00585	0.061433	0.03702	0	0.5
PIC24	0	0.091483	0.0147	0	0.00374	0	0.16245
PIC25	0	0.087583	0.01495	0	0	0	0.31615
PIC26	0	0.035183	0.0143	0	0.03342	0	0.2694
PIC27	0.006875	0.073867	0.0261	0.055233	0	0	0.357
PIC28	0	0.064933	0.0193	0.015267	0.04366	0	0.32355
PIC29	0.007525	0.0526	0.01815	0.082667	0.12168	0	0.13895
PIC30	0	0.0584	0.043	0	0.06114	0	0.5
PIC31	0.0141	0.01575	0.00685	0.0124	0.08798	0	0.2432
PIC32	0	0.074983	0.0084	0	0.11196	0	0.3946
PIC33	0	0.0949	0.00315	0.028833	0.02364	0	0.5
PIC34	0.0972	0.005117	0	0	0.2322	0	0.1048
PIC35	0	0.1049	0.0607	0.011333	0.14204	0	0.33105
PIC36	0.047025	0.077283	0.00935	0.002667	0.13282	0	0.2738
PIC37	0.035425	0.047883	0.0034	0.012533	0.20666	0	0.2673
PIC38	0.018725	0.048	0.0048	0.011633	0.14744	0	0.2348
PIC39	0.03515	0.113967	0.00615	0	0.08654	0	0.22245

, which presents the statistical data obtained from image decoding (see Appendix A), and

Table A2. Statistical data of mode calculation from questionnaire.

	MODE_Q1	MODE_Q2	MODE_Q3
PIC1	3	3	3
PIC2	3	3	3
PIC3	4	4	3
PIC4	3	3	3
PIC5	3	3	3
PIC6	3	3	3
PIC7	4	3	3
PIC8	3	3	3
PIC9	3	3	3
PIC10	4	4	4
PIC11	3	3	3
PIC12	3	3	3
PIC13	3	3	3
PIC14	3	3	4
PIC15	3	3	3
PIC16	3	3	3
PIC17	3	3	3
PIC18	3	4	3
PIC19	3	3	3
PIC20	4	3	3
PIC21	4	4	3
PIC22	4	3	3
PIC23	4	4	3
PIC24	3	4	4
PIC25	4	4	4
PIC26	3	3	3
PIC27	3	3	3
PIC28	3	3	3
PIC29	3	3	3
PIC30	2	2	2
PIC31	3	3	3
PIC32	3	3	2
PIC33	3	3	3
PIC34	3	3	3
PIC35	3	3	3
PIC36	2	2	2
PIC37	2	2	2
PIC38	2	2	2
PIC39	3	2	2

, containing the mode calculation results from the questionnaire (see Appendix C)—were combined for analysis of correlations to the following results (see in

Table 6. Summary of statistical data results.

Variable		Form	Space	Movement	Functional	Emotional	Object	View	Mode _Q1	Mode _Q2	Mode
FORM	Spearman’s Rho	--
	p-value	--
SPACE	Spearman’s Rho	0.133	--
	p-value	0.420	--
MOVEMENT	Spearman’s Rho	−0.381 *	−0.116	--
	p-value	0.017	0.484	--
FUNCTIONAL	Spearman’s Rho	−0.060	0.055	−0.067	--
	p-value	0.718	0.737	0.638	--
EMOTIONAL	Spearman’s Rho	0.311	−0.195	−0.005	−0.019	--
	p-value	0.054	0.235	0.974	0.909	--
OBJECT	Spearman’s Rho	0.245	0.202	0.144	−0.029	−0.043	--
	p-value	0.132	0.218	0.381	0.860	0.794	--
VIEW	Spearman’s Rho	−0.375 *	−0.177	0.308	0.149	−0.257	−0.262	--
	p-value	0.019	0.281	0.057	0.364	0.115	0.108	--
MODE_Q1	Spearman’s Rho	−0.213	0.160	0.102	0.011	−0.405 *	−0.036	0.132	--
	p-value	0.193	0.329	0.537	0.949	0.011	0.830	0.423	--
MODE_Q2	Spearman’s Rho	−0.228	0.133	−0.007	0.109	−0.374 *	−0.018	0.020	0.737 ***	--
	p-value	0.162	0.420	0.965	0.511	0.019	0.915	0.903	<0.001	--
MODE_Q3	Spearman’s Rho	−0.329 *	−0.038	0.187	0.100	−0.457 **	0.019	0.095	0.567 ***	0.742 ***	--
	p-value	0.041	0.817	0.253	0.546	0.003	0.909	0.564	<0.001	<0.001	--

* p < 0.05, ** p < 0.01, *** p < 0.001.

).

In this analysis, the researchers chose to use Spearman’s rank correlation coefficient (Spearman’s Rho) because the variables from the questionnaire were measured on an ordinal scale. Each row represents a specific image. The responses to Questions 1 to 3 were calculated using the mode from all 39 respondents. This was done to reduce the dimensionality of the dataset from three dimensions (respondents, images, and architectural aspects) to two dimensions (images and architectural aspects). In this table, an asterisk (*) following the correlation coefficient (Spearman’s rho) indicates the statistical significance level of the correlation between variables, meaning that the higher the statistical significance, the more reliable the results.

From this analysis of the Spearman’s Correlations table, it was found that the variable Other Emotion (OTHEREMO) has a statistically significant correlation with the responses to Question 1 (Do the presented images encourage you to walk [on the sidewalk]?), Question 2 (How much do these images influence your motivation to walk more or less often?), and Question 3 (Do the images inspire you to recommend others to walk [on the sidewalk]?), with Spearman’s rho values of –0.405 * (p = 0.011), –0.37 4* (p = 0.019), and –0.457 ** (p = 0.003), respectively. These results indicate significant negative correlations at varying levels, particularly for Question 3, which shows significance at the p < 0.01 level.

Therefore, it can be concluded that Other Emotion has a statistically significant influence on respondents’ answers to Questions 1 through 3. In other words, the Other Emotion element is a built environment or sidewalk design factor that negatively affects the motivation for people to walk.

5. Discussion and Conclusions

This study aims to mitigate global warming by promoting walking [1,2,16,17,18]. Therefore, this research raises Question 1, which asks: What are the characteristics of walkable sidewalks in tropical humid urban areas? We identified design approaches for sidewalks or the built environment that encourage walking in a tropical humid climate, based on each location in Singapore. These locations include Boat Quay, Chinatown, Orchard Road, and Marina Bay [187,188,189,190]. They share similar components, with the top three average most frequently found elements in each area being as follows: natural light in the view elements, trees in the space elements, and sidewalks in the emotional elements.

The identified components are consistent with previous research, as discussed in Section 2.2 [45,46,47,48,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176]. Additional components were identified beyond those reported in previous studies, elements that represent significant trends in pedestrian walkway design for tropical humid environments. It can therefore be stated that natural light in the view elements, trees in the space elements, and sidewalks in the emotional elements have particularly strong potential. Therefore, future research should focus on the design of sidewalks in tropical humid areas, emphasizing these specific elements.

From the literature review that found green spaces significantly influence the desire to walk, the second research question was posed as follows: What are the design guidelines for sidewalks related to green spaces in tropical humid areas that effectively encourage people to walk? Based on the case study of Singapore, we found that the emotional element negatively influences the motivation for people to walk. In other words, the sub-elements within Other Emotion, or the category of attractiveness—which includes factors that encourage walking such as vibrancy [36,49]—have a negative impact in this context and social interactions that are ambiguous or open to multiple interpretations (ambiguity) [33], among others. This negatively impacts people’s decisions to choose walking as transportation, reducing their attraction to walk again or to encourage others to walk. Although this study did not find clear evidence that sidewalk elements combined with green spaces strongly encourage people to walk, the statistically significant negative results may indicate the need to reduce or omit this element in sidewalk design aimed at encouraging walking in the future.

In summary, what are the characteristics of walkable sidewalks in tropical humid urban areas? The authors found that walkable cities in tropical humid areas feature natural light, as a key component within the category of view elements, trees, within the category of space elements, and sidewalks, within the category of emotional elements, are abundant. Academically, it is recommended that designers prioritize these elements when designing pedestrian walkways in tropical humid climates in the future, due to their high potential to promote walking suitable for tropical humid climates in particular.

Simultaneously, what are the design guidelines for sidewalks related to green spaces in tropical humid areas that effectively encourage people to walk? Our analysis concluded that elements within the Other Emotion category, such as vibrancy and ambiguity, significantly influence the design guidelines for sidewalks in tropical humid areas in relation to green spaces, but they have a negative impact on the motivation to walk, which may discourage people from returning to walk or inviting others to walk together. The results may have implications for designers to consider reducing or modifying these elements in future designs to better promote walking (see in Figure 4).

A limitation of this study may be related to respondents not experiencing the actual environment through direct sensory perception, but rather through images presented in the online questionnaire. Therefore, future research should further investigate sidewalk elements in which green spaces play a significant role in influencing the desire to walk by developing a questionnaire format that enables participants to better perceive and experience the actual environment, which may lead to different outcomes. In addition, other elements that did not show statistical significance may also be topics worth exploring further in future research. Since the results differ from previous studies, it is important to note that this research was conducted solely through image-based questionnaires. Furthermore, the findings are based exclusively on data collected in Singapore. Therefore, collecting data in other locations may yield different results. Future studies should be conducted in real settings or in tropical humid countries different from that examined in this research, in order to further verify these findings. Lastly, although the number of 39 respondents is sufficient for conducting a preliminary survey-based study [196,197], there are several approaches to determining an appropriate sample size, with the most commonly used method being based on Cronbach’s alpha [198]. This may lead to different outcomes from the present study and thus serve as a guideline for future research.