A Study on Pedestrians’ Satisfaction and Preferences for Green Patterns according to the Sidewalk Width Using VR: The Case of Seoul, South Korea

Abstract

Pedestrian-friendly cities are gaining traction worldwide. This study focused on sidewalk width and green space designs that comprise the walking environment. This study examined uniform planting patterns made without considering the width of the sidewalk and derived an appropriate green area pattern created according to the width of the sidewalk. We conducted a survey using virtual reality, satisfaction and preference review, and multilinear regression analysis. The results showed that ensuring safety through planting on a narrow sidewalk with a width of less than 3 m and 3 m to 5 m had a higher effect on satisfaction, while places with sufficient shade environments had an effect on overall satisfaction for a sidewalk width of 5 m to 8 m or more. The green spots were not quite preferred; on the contrary, there was a popular opinion that many green spots felt stuffy. This study is meaningful in that it identified the reason for appropriate planting plans, according to the width of the sidewalk, by applying the changing traffic paradigm, and conducted the study from the perspective of pedestrians. In addition, this study demonstrated the possibility of using virtual reality in the planning of smart cities, by applying a new research methodology using VR to visualize tasks that are difficult to perform in reality.

1. Introduction

1.1. Pedestrian-Friendly Environments

As it has become increasingly important to prioritize cities’ pedestrian-friendliness, countries worldwide have implemented various pedestrian policies. Walking is the most basic mode of transportation that people can use independently and is the most common and safest form of exercise [1]. In addition, walking improves the quality of life of urban residents by revitalizing the streets and reviving the city [2,3,4]. Seoul has strived to transition to a pedestrian-friendly city and has actively implemented various pedestrian-related projects since 2012. Accordingly, the projects have increased social awareness and conditions have improved [5]. In this context, the ways to improve the safety and convenience of pedestrian behavior have emerged as a core area of policy worldwide [6].

Along with the expansion of sidewalks, the composition of the widened sidewalk has changed. Sidewalks are typically widened by increasing green space, such as the number of trees and green belt areas, and providing bicycle lanes for cyclists [7,8]. Green spaces also serve as a boundary between bicycle lanes and walking spaces and increase as the sidewalk widens. As such, green spaces have become a key factor in creating the pedestrian environment. Many cities across the world aim to be carbon neutral [9]. In the pursuit of carbon neutrality, it is essential to identify and implement effective solutions that can reduce carbon emissions and promote sustainability. One important solution for achieving this goal is the incorporation of green spaces into urban environments. Green spaces, such as parks, gardens, and green roofs, can provide numerous benefits, from absorbing carbon dioxide and reducing the urban heat island effect to improving air quality and enhancing biodiversity. These benefits can help mitigate the negative impacts of urbanization and support the transition to a more sustainable future. Moreover, the incorporation of green spaces can also enhance the quality of life for urban residents by providing recreational opportunities, improving mental health, and reducing stress. Overall, the promotion and expansion of green spaces can play a crucial role in achieving carbon neutrality and creating more livable and sustainable cities. Street trees offer one of the most cost-effective options to sequester carbon dioxide and, thereby, offset the high quantities of embodied carbon that are embedded in our modern metropolitan infrastructure [9]. Trees in the streets alone are insufficient to neutralize the CO₂ emitted in cities; therefore, parks, tree-lined squares, and backyards with trees are important spaces where planting should be introduced. Street trees are fundamental for the attraction and maintenance of wild birds, i.e., they play a part in the conservation of urban biodiversity [10]. It has become more important to focus on qualitative aspects, including the nature and functionality of the space, rather than simply increasing the amount of green space [11].

1.2. Utilization of Virtual Reality (VR)

Virtual reality (VR) is an advanced technology that combines high levels of control and validity to simulate highly realistic environments by leveraging basic neuroscience research and treatment applications [12,13]. Since VR can effectively induce emotions [14] and simulate highly realistic environments [15], the technology provides more environmental information and creates a more realistic environmental experience than two-dimensional media such as pictures. Additionally, VR has provided a new way for people to better understand the world. In the past, people could only experience the world personally, but now, they can use natural ways to interact with the virtual environment and help create and experience the virtual world [16]. Thus, VR use is increasing in restorative evaluation, particularly regarding urban parks [17,18,19]. Furthermore, there are some benefits of using VR in designing smart cities: capability to assess design ideas in real time and within a 3D space during the design and planning phases; effective communication among different stakeholders, academics, planning professionals, and communities; and significant time saving by excluding guesswork in design [18].

A VR environment is built by utilizing 3D programs, such as Unreal Engine or Lumion, or by photographing real spaces with a 360° camera. This study aims to investigate the preference for green space designs by asking citizens to complete a satisfaction survey and providing them with different designs based on the width of the sidewalk at the research site in a VR environment.

In this study, “satisfaction” refers to the degree of satisfaction (satisfied vs. dissatisfied) with the green space design of the actual pedestrian space in the virtual environment, while “preference” refers to the degree to which civilians like the green space design of the pedestrian space in the virtual environment [7,19,20,21,22,23]. From an environmental psychology perspective, there is a well-established relationship between nature and satisfaction or preferences, but it is heavily influenced by other factors, such as passing vehicles and barking dogs [13,24,25]. The use of VR can compensate for these shortcomings [13,26]. In addition, studies have shown that analyzing preferences using virtual environments is not very different from deriving results using a real environment [27,28,29,30,31,32].

1.3. Novelty

In the process of designing urban spaces, it is essential to consider how people will react to and interact with the environment. To gain insights into people’s responses to design plans, a VR-based approach was employed to evaluate the plans at eye level. This approach can help identify potential issues and improvements in the design plans and provide valuable insights into the user’s experience of the space. Overall, the use of VR technology at eye level can facilitate the development of more user-centered and sustainable urban environments and also contribute to the creation of more-livable cities.

This study used different data collection methods such as VR, and the data were divided into two categories, “satisfaction” and “preference”. By using VR, we expect to see the same effect as that derived from the actual environment, and we believe that it is possible to derive reliable research results by providing a survey environment that gives participants a high level of understanding.

Compared to previous studies that focused on constructing VR environments in a linear form [14,15,16,17,18,19], this study stands out for its exploration of multiple alternatives in VR environments. By doing so, this research has opened up the possibilities of utilizing virtual spaces and expanded the scope of research in this field. The ability to create and analyze different VR environments can provide valuable insights into the design of urban spaces and user experiences, leading to more informed decision-making in the planning process. Moreover, this study’s approach has significant academic novelty, as it highlights the potential of VR technology in the field of urban design and planning and encourages further research in this area. Overall, the results of this study can contribute to the development of more effective and user-centered urban design and promote the use of VR technology as a planning tool for future projects.

We asserted that a uniform green area made walking difficult, particularly if it was not determined based on the width of the sidewalk. Green spaces are important in terms of carbon neutrality. Consequently, the research question “Will walking satisfaction increase as green spaces increase?” was chosen. Considering that uniformly planted trees regardless of the width of the sidewalk is problematic, this study aimed to present appropriate green space design options according to sidewalk width based on the perspective of pedestrians by using VR.

2. Materials and Methods

2.1. Study Area

The study area for this research comprised eight important pedestrian streets designated by the Seoul Metropolitan Government. The eight study areas are included in the Connecting Trail in Seoul, South Korea (Figure 1). The Connecting Trail was established by the Seoul Metropolitan Government in 2019 and is in Seoul City Wall. This is the central road in Seoul, which serves as a landmark for “Walking Friendly City, Seoul.” Seoul City Wall is located in Jongno-gu and Jung-gu, central Seoul. “Seoul Urban Pedestrian Street” aims to shift from automobile-centered to people-centered traffic, thus improving the quality of citizen life by promoting health and improving eco-friendly comfort.

Accordingly, the Connecting Trail was selected as the target destination because it connects Korean history and tourist attractions and is located in the city center where floating populations, such as tourists, are concentrated (Figure 1).

The pedestrian-width standards presented in this study are classified into four categories per the standards presented in the Seoul Metropolitan Government’s 2010 report status statistics [33] and the basic plan for tree planting management [34]. In the statistics report on the current status of sidewalks in Seoul, the sidewalk width is reported to be between 3 m and 10 m. Accordingly, the sidewalk width was classified in this study as follows: less than 3 m, between 3 m and 5 m, between 5 m and 8 m, and more than 8 m.

A total of eight destinations were selected as places with landmarks and a large floating population including tourists and ordinary citizens, two for each sidewalk width. The current satisfaction analysis was conducted on a total of eight destinations, and the preference analysis was conducted at destinations in which pedestrian environment improvement work had been performed.

2.2. Process of Designing the VR Environment

In this study, the process of building the VR environment can be summarized in five phases. We used VIVE PRO EYE as the VR device; it reenacts images using its own display. The preference survey consisted of five green space designs according to the width of the sidewalk, and the green space designs were transformed using the Lumion 11.5 program. The following five steps were undertaken (Figure 2):

(1)

We visited and captured the site with a RICOH THETA V 360° camera. The shooting height was unified to 2 m, which was the height when the researcher’s arm was raised upward; shooting was carried out three times in May 2022.

(2)

We saved the image as a .jpg in panoramic format using the 3D tool provided by Adobe Photoshop CC 2018. This removed unnecessary parts, e.g., the photographer, from the original image and synthesized it to provide a better environment for study participants during the survey.

(3)

We then converted the .jpg format of the panorama images to the .obj format of the 3D images. The Lumion 11.5 program requires 3D images, because it can only read 3D files. Therefore, we performed UV Editing, a three-dimensional modeling process that utilizes the Blender program to transform a 2D picture into a 3D model. The processed panorama image was mapped to a spherical 3D object, converted into a 3D file, and stored.

(4)

The files for each destination were converted into 3D files and imported into the Lumion 11.5 program. We created a green space design for each classified sidewalk-width. The created image was rendered and stored in a 360° panorama within the program.

(5)

Since participants must be shown images using VR, it is necessary to link them with VR equipment. Using the Steam VR program provided by Steam, the world’s largest electronic game software distribution network developed and operated by Valve Corporation, we connected to “media player” and set a 360° format to view horizontal images on head-mounted displays.

2.3. Data Analysis

Prior to conducting statistical analysis on the eight pedestrian spaces, we used VR to analyze the design plans at eye level. We established the VR environment and constructed the framework of the survey. In this study, we conducted a satisfaction survey and a preference survey as part of our situation analysis to better understand users’ attitudes toward the urban environment and potential improvements. The satisfaction survey was designed to measure users’ overall satisfaction with the urban environment and identify areas that require improvement. The preference survey was conducted to assess users’ preferences for various design options and to help determine the most effective design interventions. To analyze the results of the satisfaction survey, we used multiple regression analysis, which allowed us to identify the most important factors influencing users’ satisfaction with the urban environment. For the preference survey, we used t-tests to compare the mean scores of different design options and consider the possibility of differences in recognizing a VR environment between groups, based on whether they wanted to visit the destination. The results of these surveys provided valuable insights into users’ attitudes and preferences and helped inform the enhancement of urban space. The details are as follows.

2.4. Survey Overview

The study aimed to investigate preferences regarding sidewalk width by comparing satisfaction surveys of the current green space design (eight target sites) and various newly created green space designs (four target sites) using VR. The survey was conducted to assess users’ perspectives while shifting toward a pedestrian-centered environment. Participants were healthy individuals aged 19 years or older with street pedestrian experience, and those who had not visited more than 60% of the eight research sites were excluded. Participants who were able to compare the difference between reality and VR were selected, considering the use of VR in the study. Since the survey was conducted by wearing a VR device, it was suitable for healthy people except for the blind. Healthy participants aged 19 or older with walking experience were recruited for the experiment through message boards and social networks (e.g., KakaoTalk open chat rooms) in July 2022. In total, 32 participants were selected for the experiment. Among them, 13 were male and 19 were female. Studies that have conducted experiments using VR used data from approximately 30 people; thus the data gathered from 32 people in this study was considered appropriate [15,31]. The study was approved by the IRB review at the authors’ institution (No. 2207/001-007)). Written informed consent was obtained from the participants before starting the survey. The survey process was as follows.

Participants wore VR equipment on a 360° rotating chair to view each 360° image, and their satisfaction was evaluated on a five-point Likert scale upon viewing the eight pedestrian sites. The evaluation indicators used in the satisfaction survey were largely divided into three categories; the pedestrian environment was evaluated with a total of nine items with three evaluation factors for each index. The preference survey evaluates the preferred rankings and scores upon viewing a total of 20 VR images with five different green space designs according to the width of the sidewalk. Based on the satisfaction and preference surveys, green space design guidelines suitable for sidewalk width could be established (Figure 3).

2.4.1. Satisfaction Survey

The satisfaction survey was divided into three parts: walkable environment, easy walking environment, and walking-inducing environment. The evaluation factors for each indicator are shown in

Table 1. Survey Questions Concerning Sidewalk Satisfaction.

Index	Factor		Questions
Walkable environment	F1	Valid sidewalk width	- Is there enough space for walking? - Is the sidewalk width unsafe due to planted trees?
	F2	Managed condition	- Is the sidewalk well maintained and comfortable to walk on? - Is there any distortion of the sidewalk due to tree roots?
	F3	Pedestrian safety	- Is the boundary planting done well? - Is the environment safe for pedestrians to walk in?
Easy walking environment	F4	Connectivity to other spaces	- Is there connection to other pedestrian spaces? - Is there uniformity of planted materials?
	F5	Continuity with other spaces	- Does the green space design lead to the next walking space?
	F6	Ease of getting directions	- Is the sidewalk easy to remember and does it have its own characteristics? - Is the green space design representative of the street?
Walking- inducing environment	F7	Amount of green space	- Do landscaping and planting provide enough shade for walking or resting? - Does the sidewalk provide a comfortable environment for walking or resting?
	F8	Walking inducement level	- Is the green space on the street attractive enough to induce pedestrian passage?
	F9	Suitability of facility	- Is the sidewalk in harmony with the surrounding green space? - Are there various resting places and convenience facilities for pedestrians?
Overall satisfaction	F10	Overall satisfaction	- Are you satisfied with the walking environment focusing on green space?

Scale: 1 = not at all satisfied; 2 = a little satisfied; 3 = moderately satisfied; 4 = quite satisfied; 5 = very satisfied.

[35,36,37]. In addition, we investigated the overall levels of satisfaction to establish which factors had the most influence on overall satisfaction. Utilizing the satisfaction survey, we can analyze the level of satisfaction with the walking environment’s current design and amount of green space.

2.4.2. Preference Survey

People respond differently to the environment by choosing their preferred features and changing their behavioral performance [38]. For example, people tend to be more physically active in walkable and interconnected streets [39]. Thus, the features of the environment are closely related to human behavior and predicting the preferred environment becomes challenging for city planning [38].

The preference survey was conducted on four out of eight target sites. To select the green space design that is most suitable for the width of the sidewalk, the sites were divided into five types according to width and implemented as a VR image. The types of green space designs according to the width of the sidewalk are shown in

Table 2. Preference Survey Type and Images.

	(1)-A1	(1)-A2	(1)-A3	(1)-A4	(1)-A5
P1
P2
Type	No green space	Floor green space	1 row of shrubs	1 row of trees	1 row of trees +1 row of shrubs
	(2)-B1	(2)-B2	(2)-B3	(2)-B4	(2)-B5
P1
P2
Type	1 row of trees	1 row of trees + 1 row of shrubs	1 row of trees + 1 row of small trees + 1 row of shrubs	2 rows of trees	2 rows of trees + 1 row of shrubs
	(3)-B1	(3)-B2	(3)-B3	(3)-B4	(3)-B5
P1
P2
Type	1 row of trees	1 row of trees + 1 row of shrubs	1 row of trees + 1 row of small trees + 1 row of shrubs	2 rows of trees	2 rows of trees + 1 row of shrubs
	(4)-C1	(4)-C2	(4)-C3	(4)-C4	(4)-C5
P1
P2
Type	1 row of trees + 1 row of shrubs	2 rows of trees + 1 row of shrubs	2 rows of trees + 2 rows of shrubs	3 rows of trees + 1 row of shrubs	3 rows of trees + 1 row of small trees + 1 row of shrubs

P1: panorama view; P2: perspective view.

. The green space designs for sidewalk widths less than 3 m ((1)-A1–A5) comprised one row of trees and one band of green space. The green space designs for sidewalk widths 3–5 m and 5–8 m ((2)-B1–B5, (3)-B1–B5) comprised the same design, with a minimum of one row of trees for widths over 3 m, as well as two rows of trees and one band of green space. In the case of sub-tree designs, the aim was to plant a multilayered green space in which a sub-tree layer is added for functionality; this option was selected to confirm whether the addition of a sub-tree layer yielded positive visual results. Finally, considering that up to three rows of composition can be accommodated within widths of 8 m or more ((4)-C1–C5), the green space designs were divided into five types, each forming a multilayer design including three rows of trees, one sub-tree layer, and one band of green space. In addition, the width of the sidewalk that should be legally applied in walking environments is 2 m. Summary of the overall analysis method is Figure 4.

3. Results

The visit rate to target sites of all participants accounted for more than 60%, and responses from a total of 32 participants were used in this study. The proportion of male respondents was 40.6% (13), and for females, it was 59.4% (19). An analysis of the ratio of visits to the study site showed that 94% of respondents visited B (Cheonggyecheon-ro), and 63% of respondents visited C (Donhwamun-ro). As a result, the rate of visits to all target sites was confirmed to be more than 60%.

3.1. Satisfaction with Green Space Designs

3.1.1. Multilinear Regression Analysis

The analysis of the results found that the Durbin–Watson values of all targets were close to 2, indicating that the independent variables were valid in all targets. The study identified factors affecting comprehensive satisfaction based on sidewalk width. Sidewalks with widths less than 3 m were found to affect safety, continuity, and ease, and safety was considered more important than green spaces and rest facilities for walking spaces with narrow sidewalks. Sidewalks with widths of between 3 m and 5 m were found to be influenced by ease, comfort, connectivity, and esthetics. Management status and esthetics were found to affect satisfaction with sidewalk widths of more than 5 m and less than 8 m, where sufficient sidewalk space was available, and green spaces had a more positive effect on satisfaction. Sidewalks with widths of more than 8 m were found to affect overall satisfaction with esthetics, management status, ease of use, and comfort.

Table 3. Results of Multilinear Regression Analysis.

Dependent Variables	Independent Variables	Non-Standardization Coefficient
		(A)	(B)	(C)	(D)	(E)	(F)	(G)	(H)
Overall satisfaction	Constant	1.21	0.01	1.00	0.98	0.18	−0.08	−0.38	1.66
	F1	−0.08	0.25	−0.11	0.18	0.07	0.14	0.13	−0.18
	F2	−0.30	−0.03	0.05	−0.17	0.21	0.14	(0.13)	−0.18
	F3	(0.41)	(0.39)	−0.15	0.04	0.34	−0.05	−0.05	0.08
	F4	−0.06	0.30	−0.04	(0.26)	−0.33	0.24	0.12	0.01
	F5	(0.40)	(−0.38)	−0.08	−0.04	0.29	−0.22	−0.09	−0.09
	F6	(0.27)	0.33	(0.80)	0.09	−0.22	0.13	0.15	(0.36)
	F7	−0.08	0.29	(0.27)	−0.24	(0.36)	−0.05	0.10	(0.45)
	F8	0.08	−0.22	0.06	(0.53)	0.22	(0.44)	(0.33)	0.03
	F9	0.14	0.15	0.13	0.18	−0.10	0.20	−0.01	−0.03
Adjusted R2		0.64	0.51	0.51	0.40	0.38	0.51	0.76	0.35
Durbin–Watson		1.59	1.88	1.83	1.99	1.92	1.87	2.07	1.75

Values in brackets denote a significant value at the p < 0.05 significance level. Research target site: (A) Sungnyemun Gate; (B) Cheonggyecheon-ro; (C) Namsan Square; (D) Donhwamun-ro; (E) Sejong-daero People’s Forest Road—Seoul City Hall; (F) Heunginjimun Gate; (G) Sejong-daero People’s Forest—Gwanghwamun Station; (H) Shinsegae Duty Free. Factors: F1, Valid sidewalk width; F2, managed condition; F3, pedestrian safety; F4, connectivity to other spaces; F5, continuity with other spaces; F6, ease of getting directions; F7, amount of green; F8, walking inducement level; F9, suitability of facility; F10, overall satisfaction.

provides further details on the factors identified in the study.

3.1.2. Results of the Satisfaction Survey

The results of the satisfaction survey are shown in Figure 5, and the significant results are as follows.

Per the results of overall satisfaction on green space design, Sejong-daero—Gwanghwamun Station (G) ranked the highest at 4.28. This location received a positive evaluation as it encourages people to want to walk due to its wide sidewalk width (walkable environment) and multilayered planting design (easy walking environment and walk-inducing environment).

3.2. Preferences for Green Space Designs

3.2.1. t-Test

Before conducting the preference analysis, a t-test was conducted on an independent sample to determine whether the collected data satisfied the assumption of normal distribution. Skewness and kurtosis were used to evaluate the normality test. Generally, if the absolute value of the univariate skewness is greater than 3.0, it implies extreme skewness, and when the absolute value of the kurtosis value is greater than 10.0, there is a problem [40,41]. In this study, the absolute values of all skewness and kurtosis were less than 3.0 and 10.0, respectively, indicating that normal distribution was satisfied. After establishing an alternative hypothesis that there was a difference between the results of the preference survey according to whether the user had visited the site, an independent sample t-test was conducted. The hypothesis of the t-test was that “There will be a difference in preferences depending on whether they wanted to visit the destination.” The result showed that not all variables were significant, and there was no difference in the preference results according to whether users had visited the site. Therefore, VR was used to increase the reliability of deriving the research results.

3.2.2. Results of the Preference Survey

Next, we present the analysis results for the green space design preference survey according to sidewalk width (Figure 6). The t-test for preference analysis was carried out targeting Sungnyemun Gate (A), Donhwamun-ro (D), Seoul City Hall (C), and Shinsegae Duty Free (H), which are representative cases of sidewalk width.

(1)-A3 was the most preferred green space design for sidewalk widths less than 3 m (3.69). The most preferred green space designs for sidewalk widths between 3 m and 5 m was a multilevel design with one row of trees and one row of shrubs. As for the preferred green space design for sidewalk widths between 5 m and 8 m, (3)-B5 rated the highest. The most preferred green space design for sidewalk widths over 8 m was (4)-C2.

4. Discussion

4.1. Important Factors for Walking Areas

In this study, we investigated important factors affecting walking environments. As a result, green spaces were identified as the most important factor. In walking environments, the role of green spaces accounted for a higher proportion of shade and boundary functions than other functions (Figure 7). This supports the results of the satisfaction survey and the preference survey.

Analyzing the results focusing on the walking environment, it is evident that the boundary function, in terms of safety, and the shading function, with regard to comfort, were identified as important factors. Since the importance of green space functions may vary depending on the environment, it is necessary to consider them according to the environment on a case-by-case basis.

4.2. Summary

By analyzing the green space design suitable for each sidewalk width from the user’s point of view, this study found that people prefer “one row of shrubs” for sidewalks narrower than 3 m, “one row of trees + one row of shrubs” for sidewalk widths between 3 m and 5 m, “one row of trees + one row of shrubs” for sidewalk widths between 5 m and 8 m, and “two rows of trees + one row of shrubs” for sidewalks wider than 8 m (

Table 4. Current Images and Images of the Most Preferred Green Space Designs.

	Top View	Satisfaction Analysis	Preference Analysis
<3 m
3–5 m
5–8 m
>8 m

Note. The images under “Satisfaction analysis” are actual photographs of the sites, and the images under “Preference analysis” are implemented in VR.

). It is determined that safety is important for narrow sidewalks, and the visual beauty of green space design is prioritized for wide sidewalks over safety due to the width’s inherent stability. As shown in the table below, there were differences between the current images and the participants’ preferences.

4.3. Limitations and Suggestions

This study has three key limitations. First, there are inherent limitations of the data, which were acquired through subjective evaluation rather than objective measurement. The participants’ responses were confirmed to show good reliability, but we cannot completely rule out the possibility of unreliability. Second, in this study, only the width of the sidewalk and green space design were considered, but more generalizable analysis results could have been derived by further considering the surrounding environment, such as the number of roads and pedestrian volume. Third, a fundamental problem of VR is that wearing VR equipment for a long time may cause fatigue or dizziness, which may reduce concentration. In this study, a short break time was provided in the middle of the survey, but the possibility of reduced concentration cannot be ruled out completely. In this regard, this study used a static image that can rotate 360°, but if future research were conducted with a dynamic image using a video that rotates 360°, participants might have concentrated better, thereby stimulating greater participant interest.

Finally, empirical data on the green space design of pedestrian spaces classified by sidewalk width were presented in this study, and green space designs are expected to be important basic data points for planning pedestrian spaces in the future. More systematic follow-up studies are expected to focus on factors with strong influencing relationships among other areas of satisfaction.

5. Conclusions

This study focused on sidewalk width in a pedestrian space and conducted an empirical analysis on green space designs suitable for various sidewalk widths. To provide basic data for planning pedestrian spaces as they become more user-centered in the future, this study analyzed users’ satisfaction with sidewalk green space designs and their preferences for designs suitable for various sidewalk widths.

It was found that there were different factors to be considered when designing a green space according to sidewalk width. The results differed from the research hypotheses, which expected higher satisfaction and preference as the number of green spaces in the walking space increased. The findings of this study can be understood as indicating that green areas with a scale suitable for the width were unconditionally preferred to many other green areas. This is an important finding in understanding why a row of shrubs was commonly preferred in all sidewalks. This planting is effective in guiding the direction of pedestrians’ passage and it provides a safe walking environment that serves as a boundary or buffer. In addition, this study confirmed that users do not prefer to increase the width of sidewalks and green spaces beyond a certain ratio. It was found that simply maximizing the green space can have a negative effect by causing visual complexity and frustration. Overall, our results demonstrate a strong effect of appropriate greening arrangements for sidewalk width by using VR. The main difference of our study from previous studies [14,19] is that we conducted an experiment for appropriate green area arrangement considering sidewalk width, which is a factor ignored by previous studies. Importantly, our results provide evidence for the necessity to plan suitable green spaces based on sidewalk width.

Based on these results, we suggest that different green space designs should be created according to the width of the sidewalk when developing walking environments. In devising plans for narrow sidewalks, it is desirable to add a plant border to enhance safety rather than plants to create shade; meanwhile, for sidewalks wider than 3 m, it is important to emphasize the shade to enhance pedestrian comfort. For wider sidewalks, it is desirable to add two rows of trees to ensure a sufficiently shaded environment and to add one row of plants to form a boundary and cushion. From a pedestrian’s point of view, an appropriate green space design according to sidewalk width does not necessarily equate to increasing the amount of green space for wider sidewalks. Rather, it is important to provide a design suitable for the scale of the walking space. We suggest devising a pedestrian space that considers users’ viewpoints along with functionality.

To practice carbon neutrality in smart cities, we reveal the possibility of conducting research using VR and propose to devise a pedestrian space that considers the users’ perspective, as well as functionality. In this study, the use of VR technology as a tool for conducting surveys was investigated to determine its potential benefits and limitations. The results of the analysis revealed that providing participants with a high-level understanding of the survey environment through the use of VR led to more reliable results than traditional paper-based surveys. VR technology allowed for the creation of a more immersive and interactive survey environment, which helped participants better understand the questions and provide more accurate responses. Furthermore, the use of VR technology also enabled us to collect more detailed and precise data, which can provide valuable insights for urban design and planning. These findings suggest that the use of VR technology in survey research can enhance the accuracy and reliability of data collection and, ultimately, lead to better-informed decision-making in the planning process. Overall, the use of VR technology in the planning process could help to improve the quality and safety of pedestrian spaces in the city and contribute to the overall goal of creating a more livable and sustainable urban environment.