Research on the Spatial Location Design of Guidance Signage Systems to Connect the Space of Transit-Orientated Development Sites Based on Multi-Software Analysis

Abstract

In the context of intensive urban development strategies, the Transit-Oriented Development (TOD) model has emerged as a crucial strategy, requiring a high degree of integration of various functional spaces and traffic flows in transport stations. Complex spaces and traffic flows require an effective Guidance Signage System design to ensure efficient guidance and easy transfers. In order to choose the spatial location of the Guidance Signage System in the connecting space of TOD stations and to improve the efficiency of their guidance and visual saliency, three types of connecting space, namely, channel bifurcation nodes, atrium threshold zones, and sunken plaza interface areas were selected. In total, 18 signage system setup areas were derived from the overlapping visual domains of signage and human visual domains using the Depthmap10 and Massmotion11.5 software (six areas in each type of articulation space), which were then combined with eye-tracking technology to analyze the visual saliency of the signage system’s layout position on the passengers. The experiments show that the signage location affects passengers’ visual attention to a certain extent, and there are differences in the location of high display degrees in different connecting spaces, which require differentiated layouts. This paper summarizes the best spatial location design strategy for the Guidance Signage System according to different connecting spaces, providing more scientific guidance for the spatial location design of the Guidance Signage System for sites connecting spaces. This is essential for enhancing user navigation efficiency, minimizing confusion, and improving overall spatial usability in complex environments.

1. Introduction

1.1. Background of the Study

In order to achieve low-carbon, ecological, and other construction goals, China promotes compact-oriented urban development. The TOD model, which focuses on the integrated and compact development of rail stations and the surrounding underground space, has received increasing attention as it can effectively solve the problems of urban traffic congestion, environmental pollution, and land waste [1,2,3]. However, with the promotion of the TOD model for considering a station’s connecting space, which links the transport node and the station’s commercial complex, the Guidance Signage System has also gradually emerged for use in space location design problems. A complex spatial layout and dense flow of people may easily lead to the signage being obscured, making it enter an individual’s line of sight initially, thus making it unable to effectively guide passengers [4].

1.2. Literature Review

In the academic lineage of TOD research, the Guidance Signage System, as an important carrier for optimizing spatial efficiency, has become one of the hot areas of global research in recent years. The review of global TOD research over the past two decades shows that the focus of research in this field has shifted from macroscopic transportation network planning to microscopic spatial behavior intervention and the signage system as a key medium for “space-behavior” coupling, gradually highlighting its design science and practical value. Early research primarily focused on land-use integration and transportation efficiency, but recent studies have increasingly addressed the human-centered design of transitional spaces, particularly the optimization of pedestrian flow and ways of finding systems [5]. A significant surge in TOD-related research occurred post-2015, driven by China’s rapid urbanization and the need for sustainable solutions to traffic congestion and land scarcity [6]. Notably, studies have shifted from macro-level urban planning (e.g., station hierarchy and density zoning) to micro-level spatial interactions, such as signage visibility and accessibility [7]. Several studies have highlighted the role of the Guidance Signage System in transportation hubs to improve wayfinding and guidance efficiency [8,9]. However, research on signage positioning within TOD connecting spaces remains fragmented, with the limited integration of human behavioral analytics and dynamic spatial modeling tools. In recent years, some scholars have begun to pay attention to the role of the Guidance Signage System in TOD sites, but their studies are mostly limited to static analysis and lack the consideration of dynamic pedestrian flow lines and human factors [10].

1.2.1. Overview of Connecting Space

Current research on connecting space is mostly in the theoretical direction; Aldo proposed the theory of “intermediate state” and argued that architecture should have a clear middle ground, and intermediary space provides a public place for this contradictory space [11]. Younger describes transitional spaces as follows: transitions between various public spaces should be soft, and transitions from private to public spaces should be clear, easy to access, and give a sense of security [12]. In recent years, this has shifted from theoretical discussion to practical application and has become an important topic in urban planning and transportation engineering. Researchers emphasize the functional composability of articulation space and advocate the integration of transportation, commerce, culture, and other functions into one in order to enhance the efficiency of space utilization and service quality. For example, research on the composite design strategy for the interface space of rail transits and urban complexes has proposed five design strategies for the interface space centered on plazas, building atriums, three-dimensional roofs, underground commercial pedestrian streets, and sky corridors [13].

1.2.2. Research Trends in Wayfinding Systems and Signage Design

Wayfinding systems are an integral part of urban transportation environments, and their design quality has a direct impact on passenger travel efficiency and experience. Research has shown that an efficient wayfinding system should have clarity, consistency, and adaptability [14,15]. Signage system research peaked between 2015 and 2020, focusing on signage visibility, message density, and layout optimization [16,17].

Today, more scholars have conducted a lot of research on the Guidance Signage System. Lam found that the Guidance Signage System has an important influence on wayfinding behavior by studying the layout of airport passenger terminals based on the wayfinding theory [18]. By analyzing the relationship between the location and content of the signage system settings and the wayfinding results, Xiong, Z. pointed out that the optimization of the signage system not only improves the travel experience of the passengers but also effectively alleviates traffic congestion and enhances the overall operational efficiency of the transportation system [9]. K.M. abstracted subway stations into topology maps in order to study the setup method of the Guidance Signage System and pointed out that problems in the design of the signage system can be identified in advance through simulation, and errors and confusion in their actual operation can be reduced [19]. Zhang proposed a guide map for pedestrian transportation networks to determine the best potential locations for signs [20].

However, most of these studies are based on idealized spatial models and do not fully consider the human factors and dynamic changes in the actual environment. For example, during peak hours, signs may be blocked by crowds, leading to the failure of their guidance function [21]. Therefore, how to design a signage system that adapts to complex environments and dynamic needs has become an important direction of current research. In addition, studies have shown that factors such as height, angle, font size, and the color contrast of signs can significantly affect the identification efficiency of passengers [22]. Liu et al. found experimentally that the optimal viewing angle of signs ranges from 15° to 30°, and exceeding this range leads to a significant increase in recognition time [23].

In the layout of Guidance Signage System locations, further consideration of the visual field of pedestrians can more accurately reflect the actual situation and improve the guidance efficiency of signs. Existing studies have shown that it can help to optimize the facility design; for example, Yu investigated the Beijing South Railway Station Comprehensive Transportation Hub based on the visual perception mechanism [24].

Existing research mainly focuses on the definition, composition, design principles, and optimization strategies of connecting space, focusing on theoretical guidance, lacking quantitative analysis, and urgently requiring the introduction of quantitative research methods. Most studies focus on specific environments or single factors, and there are also limitations in analysis methods, lacking the comprehensive consideration of multiple spatial environments, as well as systematic research on the optimization of the Guidance Signage System in complex transportation hubs. In addition, there is a lack of a more comprehensive assessment of the adaptability of the Guidance Signage System in the articulated space of TOD sites, which does not overcome the limitations of a single research method.

1.3. Guidance Signage System Space Location Design Specification and Related Theories

1.3.1. Norms for the Spatial Location of Guidance Signage System

With regard to the layout of the Guidance Signage System, the relevant state departments have issued relevant standards requiring localities to setup the Guidance Signage System at key locations such as starting points, finishing points, turning points, and bifurcation points so as to eliminate pedestrians’ doubts about routes. The sign should be controlled at a height within 5° above the horizon, with an offset angle of no more than 15° for static observation and no more than 45° for dynamic observation, i.e., when the pedestrian’s head is naturally rotating, and it should be ergonomically designed to remain within a sight height of about 1.5 m.

1.3.2. Pedestrian Visible Area and Visible Area of Guidance Signage System Study

Pedestrians have a semi-curved range of visual fields, including the optimal spatial field of view and the visible spatial field of view. The optimal spatial field of view is the range in which information is most easily accessible when pedestrians are looking straight ahead, while the visible spatial field of view is the range in which pedestrians are able to observe the information under the same conditions [25], which corresponds to the optimal and visible viewing angles of 60° and 120° horizontally and 25° and 50° vertically, respectively, and the clear visibility distance of the Guidance Signage System in this range is 14.10 m and 25.20 m, respectively (Figure 1).

According to the visual principle, the visible area of the Guidance Signage System forms a fan-shaped area with the sign as the apex, a vertical offset angle of 5°, and a viewing angle of 140° (Figure 2) [26]; the farthest visible distance for pedestrians is when lifting up the eyes by 5°, and the maximum observable distance of the hanging Guidance Signage System is 17,178 mm [27].

1.3.3. Guidance Signage System

(1)

Classification of Guidance Signage System

The Guidance Signage System refers to a specific space and can convey intuitive, clear visual information to achieve effective guidance for passengers through text, graphics, or symbols; it can provide guidance, direction, identification, warning, and other functions, and it is an important tool to provide wayfinding information and help pedestrians to find their way or address their behavior [28].

According to the results of the research summarized, the Guidance Signage System is installed in the following four positions: Hanging, Attachment, Ground-Standing, and Flush-Mounted installations (

Table 1. Classification of Guidance Signage System.

Hanging	Attachment	Ground-Standing	Flush-Mounted

). Since the Technical Specification for Guidance Signage System in Public Buildings (GB/T51223-2017) [29] clearly stipulates that the spatial location of the sign should be within a 5° angle upwards of the horizon, when choosing the type of Guidance Signage System, this study focuses on three types of signage: Hanging, Attachment, and Ground-Standing signs and sets them up in a base scene.

(2)

Orientation signage spatial field of view division

In the process of wayfinding, the Guidance Signage System in the connecting space leads to corresponding changes in the visual perception and behavioral habits of individuals due to the spatial variability of the nodes. Therefore, when exploring the visual prominence of the Guidance Signage System, it is necessary to make reasonable adjustments to the location area as well as the type of Guidance Signage System in the experimental scene according to the characteristics of the specific scene space. In the studies of visual scenes by scholars at home and abroad, the visual field plane is usually subdivided into several fixed gaze regions, each representing a specific gaze target. Geoffrey U [30], in his study of visual attention while driving, divided the gaze region into nine regions that do not overlap with each other (Figure 3).

1.4. Research Objective

Given the complexity and subjectivity of spatial cognition, there is a lack of objective knowledge and understanding of the wayfinding process relative to traditional cognitive experimental methods (e.g., questionnaires); ignoring dynamic interfering factors such as crowd density and visual occlusion, the problem of the occlusion of signage during peak hours significantly increases the failure rate of wayfinding, and it is difficult to quantify the impact of such dynamics through questionnaires [31,32]. In this paper, we use the spatial syntax software Depthmap10 and Massmotion11.5 software to analyze the articulation of the spatial visual domain and introduce the method of virtual wayfinding through eye-tracking technology to analyze the influence of the spatial location of the Guidance Signage System on visual saliency. It provides support for the design and visual prominence of the Guidance Signage System in the connecting space of TOD stations, aiming to optimize the layout of the spatial location of the Guidance Signage System from the perspective of passengers’ needs and enhance their travel experience and access efficiency.

2. Methods

2.1. Multi-Software Spatial Location Analysis Based on Visual Saliency

2.1.1. Research Hypothesis

Based on the literature and theoretical analyses mentioned above, it is shown that there is a relationship between the setting of the spatial location of the Guidance Signage System and the impact of visual salience. In this regard, this study proposes the following hypothesis: within the same connecting space, there is a difference in the visual perceptual salience of the placement of the Guidance Signage System, i.e., the visual appeal of the Guidance Signage System can be enhanced at certain specific locations. The visual prominence characteristics of the Guidance Signage System vary in different connecting spaces but are also related to spatial location.

2.1.2. Research Step

This study analyzes the effect of the spatial location settings of the guide signage system on the visual salience of pedestrians at TOD sites. The steps of the study are shown in Figure 4.

This study is divided into the following three steps: Firstly, three different transition spaces between the rail stations and their neighborhoods are selected as the experimental base scenarios based on existing cases and field research. Secondly, according to the research on the visual field of the Guidance Signage System, passengers’ visual perception, and the principle of ergonomics, the visual field simulation of different articulated spatial scenes using Depthmap10 and Massmotion11.5 is used to determine the location of the Guidance Signage System and improve the scene map of different spatial locations of the Guidance Signage System. Thirdly, a simulation experiment is conducted with the help of eye-tracking technology; the variability of the perceived degree of different sign placement locations is analyzed based on the eye-tracking data.

2.2. Scenario Construction

The scenario construction consists of two research steps: the experimental base scenario construction and the multi-software collaborative approach, respectively.

With reference to the Code for Fire Protection Design of Buildings, Code for the Design of Store Buildings, Uniform Standard for Design of Civil Buildings, Code for Fire Prevention in Design of Interior Decoration of Buildings, and other relevant design codes in China for commercial, metro, and public buildings, the Renmin Beilu Station, Chunxi Road Station, and Guanghua Park Station in Chengdu City are used as the basis for constructing the basic model of a connecting space, and this is combined with the results of the research and the summary of the literature to carry out the design. Minjie Li [33] analyzed the congestion points through simulation experiments, counted the stopping positions of passenger flows going to commercial complexes from the underground direction, and finally summarized the key spatial nodes, such as access bifurcations, atrium entrances and exits, and plaza entrances and exits. This was based on the interview results of relevant experts from Chengdu Metro, China Southwest Architecture, China Railway First Survey and Design Institute Group Co., Ltd. (Chengdu, China), and the contents of relevant specifications. Therefore, the size of the channel connecting the space model established in this study was taken as 37.5 m × 6 m wide (the length of the channel center axis is 37.5 m); the area of 500 m² was selected as the base model of the atrium and plaza connecting space, taking into account the fact that the spatial scale affects the flow of passengers. It is concluded by the distribution of passenger flow by Massmotion that the distribution of the density of the people is more uniform when the aspect ratio is 1:1. The business case and site interface space were used as reference models to derive the experimental base scenarios. The final experimental base scenario model was based on 1:1 physical scale modeling to restore the real scenario as much as possible. The specific scenes are shown in

Table 2. Experimental base scenarios.

Experimental Stimulus Material
Experimental base scenario diagram
Channel Bifurcation	Atrium Entrance and Exit	Sunken Plaza Entrance and Exit

.

Depthmap10, as a spatial syntactic analysis software, performs the graphical analysis of the visibility of the spatial environment, and the results obtained from the drawn axial and convex spatial analysis models reflect the permeability, accessibility, and convenience of space. MassMotion11.5 is a passenger flow simulation software based on social force modeling algorithms developed by Oasys Arup in the UK, which can provide designers with a lot of clear information, such as the way pedestrian access equipment is used, the safety of the pedestrian space, and the phenomenon of crowded spaces. Based on the theory of spatial syntax, Luo combined quantitative data and correlation analysis to explore the impact of spatial accessibility and pedestrian flow on the vitality of underground space by taking the underground space connected to rail transit stations as an example. In this study [34], Ma used Massmotion to simulate the 3D visual time of travelers on the wall, showing the focus of attention of the pedestrian’s field of view in his simulated visual time map and proposed a method to simulate the focus of attention of the view [35].

Based on the above research, this study utilizes Depthmap10 to analyze the three scenarios to obtain the visual focus area and then combines this with the signage, passenger visual field, and Massmotion11.5 passenger flow line for the visual field superposition analysis so as to achieve the design of an appropriate location according to the Guidance Signage System.

2.2.1. Visual Field Overlap Analysis

Combining the above visual area division and the type of Guidance Signage System, a three-dimensional spatial coordinate system was created to divide the visual areas, and according to the nine-grid composition method in photographic composition techniques, a straight line was drawn along each of the X, Y, and Z axes in a single-point perspective scene to form a 3 × 3 × 3 three-dimensional spatial grid, so as to divide the screen into nine independent visual areas (Figure 5), where each of these visual areas corresponds to a different location of the Guidance Signage System in the experimental scene.

Due to the continuity of the signage setup [36], each path within the connecting space covers several nodes. When laying out the locations of the Guidance Signage System, it is necessary to select suitable points from these nodes as decision points for sign setting. In this study, the locations where pedestrians face difficulties or are most likely to be confused during path selection are defined as decision points.

In this paper, we first employ the spatial syntax software Depthmap10 to analyze the three kinds of connecting spaces in terms of their visual domain before subdividing the spatial plan into a grid, which covers the entire 2D visible area, and when setting the grid size, we balanced the calculation precision and the amount of operations, referring to the research of Zhou Xi [37] and others, selecting a grid size of 1.0 m (the common size is 1–1.5 m). The structure of the visual integration degree calculation is shown in

Table 3. Analysis of Visibility in Various Connecting Spaces.

A-Channel Isoview Integration	Guidance Signage System Visual Field A1	Pedestrian Visibility A2	Field of View Overlay A3
B-Degree of integration of viewsheds such as atriums	Guidance Signage System visual field B1	Pedestrian visibility B2	Field of view overlay B3
C-Degree of integration of fields of view such as plazas	Guidance Signage System visual field C1	Pedestrian visibility C2	Field of view overlay C3

, where the redder the color, the higher the visual integration degree, which indicates the greater visual visibility of the space. Secondly, the Massmotion11.5 software is used to simulate the passenger flow routes in the three connecting spaces (Figure 6 and Figure 7), and the ground-based Guidance Signage System is laid out in such a way as to avoid the passenger flow routes as much as possible. The results of the visual field analysis of the three kinds of spaces calculated by Depthmap and Massmotion software are shown in Table 3.

2.2.2. Demonstration of Spatial Location of Standard Guidance Signage System

The experiment is based on the above nine different visual areas, the results of the visual field superposition analysis, and the actual application of the spatial layout of the situation, according to the guidance of the hanging type, attached type, and ground type to select the appropriate type of Guidance Signage System arranged in the simulation scene. Based on the literature [38] and research analysis, it can be seen that the signage system used in the process due to the different node spaces makes people produce certain visual and behavioral habit differences; thus, in the study of the signage system of visual salience, due to the space of the different experimental scenes in the location of the setup area to make certain adjustments, in Teng’s study of the visual salience of guide signs in underground commercial streets, ergonomics, and human visual characteristics were combined to divide the experimental scene into nine parts that covered the entire visual area, We followed her delineation of visual areas, but unlike Teng’s study, the spatial location of the signs mentioned in this study in conjunction with the above was within a 5° angle upward from the horizon, disregarding the three areas below the horizontal line of sight, which were not the focus of our attention. Therefore, six areas were selected as the locations of the Guidance Signage System in the scenes of channel bifurcation (A01–A06), the atrium entrance and exit (B01–B06), and sunken plaza exit (C01–C06), and the corresponding research was carried out using the following specific scenarios.

2.3. Oculomotor Simulation Studies

(1)

Experimental equipment

In this experiment, the Tobii Glasses2 ophthalmoscopic eye-tracking device was used as the experimental tool, which mainly consists of three parts: the headgear module, the recording module, and the external data processing, with a sampling rate of 50 Hz, a 1-point calibration, a scene camera with a resolution of 1920 × 1080 pixels, and a camera recording field of view ranging from 82° horizontally to 52° vertically.

(2)

Experimental Participants

A total of 25 volunteers were recruited to participate in the simulation trial, including 10 males and 15 females, with an age distribution between 20 and 50 years old, all in good physical condition and without color blindness or color weakness. In the eye-tracking experiment, we strictly followed the ethical requirements of the study to ensure that the rights and interests of all participants were fully protected. All participants were informed of the purpose of the study, the experimental procedure, and the use of the data before data collection. Meanwhile, in order to protect the privacy of the participants, all the data were anonymized or de-identified, and any personally identifiable information will not be disclosed in any research results or public reports.

(3)

Experimental stimulus material

The scene diagram in

Table 4. Scenarios of different spatial locations for Guidance Signage System.

A-Channel Bifurcation
	A01	A02	A03
	A04	A05	A06
B-Atrium entrance
	B01	B02	B03
	B04	B05	B06
C-Sunken Plaza Entrance and Exit
	C01	C02	C03
	C04	C05	C06

was used as the material for the 18-sheet visual experiment. In order to avoid the influence of color on location perception, the experimental scene was set in grey, the logo was a differentiated dark tone, and a blank page was used for the transition between each page. The research experiment is divided into four steps, and the specific flow is shown in Figure 8.

2.4. Analysis of Results

After the completion of the experiment, the experimental data were collected and sorted out, and two samples that were not qualified due to missing recorded data were excluded; finally, twenty-three qualified sample data were obtained. The qualified data were processed in Tobii Pro Lab software (Version 24.21), the required hotspot maps and eye movement data were output and exported, and the data were summarized and analyzed.

The visualization hotspot map is mainly used to obtain the distribution of eye movement behaviors in space within a certain period of time, which can reflect a large number of regions in the stimulus that attract the subject’s attention, has a two-dimensional type of data representation, and has the size of the value measured by the eye-tracking device displayed in different colors, in which the red color indicates the most focused attention and the region of the longest duration of gaze, followed by yellow, and the green color indicates the region of the least focused attention; as can be seen from the resulting visualization hotspot map, darker the red area, the more attention and focus the Guidance Signage System has from the subjects.

As shown in

Table 5. Scene hotspot maps for different spatial locations.

A01	A02	A03
A04	A05	A06
B01	B02	B03
B04	B05	B06
C01	C02	C03
C04	C05	C06

, which is the hotspot distribution map of different spatial location scenes, with the change in the deployment location, the distribution pattern of the hotspot map presents certain differences, and the comprehensive eye movement view of different spatial location scenes can be found as follows: ① For the same type of Guidance Signage System in different spatial scenes, the closer the layout position is to the pedestrian’s line of sight, the more attention it can attract and the more focused it is; the further away it is, the more dispersed it is. ② Combined with the human visual law to analyze the results of the experiment, it can be concluded that when people are observing objects, the line of sight tends to move along the direction from top to bottom and from left to right. The Guidance Signage System on the left side of the visual area is more likely to be noticed than that on the right side.

In summary, after analyzing the visual hotspot maps of each scene, it can be found that changes in the layout of the Guidance Signage System directly lead to different distribution patterns of the hotspot maps for each scene, which further confirms the viewpoints of hypothesis one: the location of the Guidance Signage System does have a significant impact on visual saliency. A reference basis is provided for the experimental results.

By analyzing the visualization hotspot map mentioned above, further in-depth investigation with the help of eye-tracking data can be conducted to clarify how the Guidance Signage System set in different locations affects visual saliency and reveals their roles. Yan Guoli [39] and others, in a review article on eye movement indicators in the field of reading research, emphasized that the selection of appropriate and effective eye movement parameters as the basis of this study is the core of ensuring the quality and depth of eye movement research. Li investigated the effectiveness of prohibited safety sign locations in a coal mine environment by collecting data on the number of gaze points and the time of the first gaze [40]. Li, H.X. selected first gaze time, the total access time, and a number of gaze points as indicators to explore the effectiveness of emergency signage during the evacuation of people in emergency situations [41].This study is an exploratory study [42], so the analysis of eye movement data such as first gaze time, the number of gaze points, duration of first gaze time, and so on (

Table 6. Mean eye movement data in the region of interest for different spatial location scenarios.

	Eye Movement Parameters	Number of Fixation (NF)	Time to First Fixation (TFF)/ms	Duration of First Fixation (DFF)/ms
Visual Area
A01 (upper left)		2.83	130	275
A02 (upper middle class)		3.10	174	475
A03 (upper right)		3.00	200	336
A04 (left and center)		2.70	78	225
A05 (epicenter)		3.80	110	291
A06 (middle right)		3.21	246	429
B01 (upper left)		2.33	187	640
B02 (upper middle class)		2.33	226	344
B03 (upper right)		1.75	96	360
B04 (left and center)		2.19	233	250
B05 (lower left)		4.00	139	274
B06 (middle right)		2.82	80	401
C01 (upper left)		2.25	71	170
C02 (upper middle class)		3.38	186	229
C03 (upper right)		1.89	115	388
C04 (left and center)		2.00	222	641
C05 (lower left)		3.77	148	397
C06 (middle right)		2.14	182	415

) during the process of wayfinding indicates the visual perception of the subjects, and the different scenes are classified and sorted in combination with the experimental data (

Table 7. Concept of eye movement metrics and sorting of eye movement data in areas of interest for different spatial location scenarios.

Eye Movement Index (EMI)	Interpretation of Indicators	Sort
Time to first fixation	Refers to the time it takes for a participant to first gaze at a specific AOI region, with smaller TFF values indicating that the region was noticed by the subject in the shortest possible time.	A04 < A05 < A01 < A02 < A03 < A06
		B06 < B03 < B05 < B01 < B02 < B04
		C01 < C03 < C05 < C06 < C02 < C04
Number of fixations	Refers to the total number of gaze points in a given AOI region, with larger NF values indicating that the region is more noticeable to the sub-fixation ject.	A05 > A06 > A02 > A03 > A01 > A04
		B05 > B06 > B02 = B01 > B04 > B03
		C05 > C02 > C01 > C06 > C04 > C03
Duration of first fixation	It refers to the duration of the first gaze in a specific AOI region, and a larger DFF value indicates that this region is more attractive.	A02 > A06 > A03 > A05 > A01 > A04
		B01 > B06 > B03 > B02 > B05 > B04
		C04 > C06 > C05 > C03 > C02 > C01

). Changes in eye movement indices were statistically described and plotted on a line graph (Figure 9 and Figure 10).

In the study of the impact of the spatial location of the Guidance Signage System on visual salience, the time to first fixation is a crucial eye movement index. It directly reflects the degree of attention and attraction of the Guidance Signage System’s placement and can be used as an important basis for preliminary screening and assessment of the advantages and disadvantages of placement. However, in order to have a more comprehensive understanding of the influence of the location of the Guidance Signage System on visual saliency, it is also necessary to comprehensively consider other eye-movement indicators as well as other factors in the actual scene.

In the scene of the channel bifurcation, the TFF value of area A04 (middle left) is the smallest, which indicates that the Guidance Signage System was quickly noticed by the subjects, while its NF and DFF values were small relative to those of the signs in other locations. For the sign in area A02 (upper middle), although its TFF value is larger than that of area A04 (middle left), its NF and DFF values are the largest. Therefore, on balance, the visual prominence of the Guidance Signage System is greater when it is set in visual area A02 (upper center). In this way, based on the statistical frequency of the three eye movement indicators, it is concluded that in the atrium entrance/exit scenario, it is difficult for pedestrians to quickly notice the Guidance Signage System located above the visual area, which is due to the complex environment of the atrium, and the surrounding arrangement of the commercial area, which, to a certain extent, distracts the visual attention of pedestrians. The significance of the Guidance Signage System located in the visual area of B05 (lower right) is higher, which indicates that the closer the distance of the same type of Guidance Signage System is from the pedestrians’ line of sight, the easier it is to attract their attention; in the sunken plaza scenario, the significance of the Guidance Signage System is higher when it is set in the visual area of C05 (lower left). It is also confirmed that in the connecting space of different scenes, the location of the more visually salient Guidance Signage System varies, indicating that there is variability in the distribution of the focus of visual attention between different scenes.

When looking through Figure 10, it can be noticed that the trend of the folds in the two charts (a) and (c) are similar. In these charts, the trends of TFF and DFF are synchronized. For example, in region A03, both TFF and DFF reach higher values, showing the stronger attraction of this region to observers. Regarding other regions such as A01, A06, etc., TFF and DFF show relatively consistent upward or downward trends, which indicates a strong correlation between visual attraction and dwell time in these regions [43]. However, the situation in (b) is different. Although the values of TFF and DFF varied from region to region, there was a clear divergence in their trends. For example, region B04 has relatively low TFF and a high DFF value, implying that although visual attention is rapidly focused, the dwell time is longer. Conversely, region B05 showed the opposite situation, with higher TFF and lower DFF, possibly indicating that although the observer’s initial gaze was more rapid, interest in the region did not last long [44].

3. Discussion

From the discussion, it can be concluded that the spatial location design of signage systems for articulated spaces at TOD sites plays a crucial role in enhancing visual salience and guidance efficiency. By combining software tools such as Depthmap10 and Massmotion11.5 with eye-tracking technology, this study identifies the optimal placement strategies for signage in different types of articulated spaces (e.g., passageway bifurcations, atrium entrances and exits, and entrances and exits of sunken plazas). The results of this study emphasize that signage locations should be differentiated according to the spatial characteristics of different articulation spaces in order to maximize visual attention and ensure smooth passenger flow. This study provides a scientific basis for the design of signage systems at TOD sites and practical guidance for the efficient operation and user-friendliness of urban transportation hubs.

3.1. The Spatial Location of the Guidance Signage System Is Closely Related to Visual Prominence

3.1.1. Differences in Location Lead to Significant Differences in Visual Saliency

The results show that the Guidance Signage System located in the visual areas A02 (upper middle), A05 (middle), B01 (upper left), B05 (lower right), C02 (upper middle), and C05 (lower left) are more likely to attract the attention of the subjects. In Geoffrey U’s study [30], it is clearly stated that the road far ahead and mid-ahead attracted more fixations than any other part of the scene, i.e., the upper middle and center positions; by contrast, the road near the left and road near the right tended to attract fewer fixations than other parts of the scene, i.e., the lower left and lower right positions, which differ from our findings, and the reason for analyzing this may be that Geoffrey U’s study may have focused more on the road driving scene, where the spatial layout of the driving scene is relatively simple, and the visual attention of pedestrians is mainly focused on the front of the vehicle. However, this study focuses on the Guidance Signage System within a TOD site; the complexity of the scene and the different functional requirements require pedestrians to make judgments at multiple decision points, leading to differences in the distribution of subjects’ visual attention, and the present study focuses more on guiding pedestrians to make quick decisions in complex spaces, while Geoffrey U’s study may focus more on the processing of visual information during the driving process. Second, this study used eye-tracking technology, and compared to Geoffrey U’s study, the eye-tracking data provided more precise information about visual attention points, allowing for a more detailed and accurate analysis of pedestrian’s visual attention. Accordingly, the results show that the hanging and attached Guidance Signage System are setup in the middle of the visual field and above, and the closer the stand-up Guidance Signage System is to the line of sight, the easier it is for them to be gazed at, and they have a higher degree of visual significance, which verifies research hypothesis one. The spatial location occupied by the more visually salient Guidance Signage System varies in different connecting spaces, which validates research hypothesis two. According to human visual patterns and ergonomics, the Guidance Signage System should be placed within the natural line of sight of pedestrians and in accordance with the optimal and visible spatial field of view. It explains why a Guidance Signage System located in the upper center and right in the middle are more likely to be noticed, and these positions are more in line with human visual habits. Secondly, Depthmap’s visual field analyses showed that signs are more likely to be seen in areas where there is a high degree of visual field integration. These areas are more visually appealing and attract more eye contact.

3.1.2. Advantageous Locations Should Be Prioritized for Signage System Design

In the process of pedestrian wayfinding, the decision point is the location where passengers need to find information the most; for example, when pedestrians arrive at a decision point, they will be guided by the information guiding signs at that decision point, so the advantageous location is set based on the pedestrian decision point, not for anyone in any location [27]. According to Sijing Teng [38], the upper middle, middle, left middle, and right middle regions are prone to form visual foci, where the upper middle and middle regions are the same as in this study; this suggests that these advantageous locations should be prioritized in the design of our signage system. But the left middle and right middle regions are different from the above study. For example, in some scenes of this study, the Guidance Signage System located in the lower right or lower left position (B05, C05) showed high visual salience, while some Guidance Signage Systems located in the central or upper area (A03, A06) were relatively low. The reason for this may be related to the spatial layout of the specific scene, lighting conditions, and other factors. In addition, the visual preference and behavioral habits of different subjects may also have a certain impact on the experimental results, and the location also needs to be analyzed and selected comprehensively in concert with the expression of color and logo content, whereas the present experiment excluded the design of the logo itself in terms of content and color, and focused on the impact of location on visual perception.

3.2. A Proposal for a Spatial Location Design Method for Guidance Signage Systems Based on Multi-Software Simulation

From the results of the study, the TOD site connecting space Guidance Signage System design should be adapted to local conditions in the design stage for scientific and reasonable design. Priority should be given to areas where pedestrians frequently stop and need to make decisions, such as the upper center, right in the middle, and some specific low areas. These areas are usually high-probability areas of visual focus, and signage systems placed in these locations can maximize visual attention and improve the efficiency of information conveyance. Meanwhile, for different types of articulated spaces, such as passages, stairways, entrances, and exits, the layout of the signage system should be adjusted according to the needs of the spatial function to ensure that the signage system can match the spatial characteristics and meet the cognitive needs of the pedestrians. At present, the existing Guidance Signage System often relies on experience and norms; the lack of a more scientific design and method for the layout cannot meet the needs of passengers to find their way. If the arrangement is inappropriate, it will need to be improved and adjusted at a later stage, which will consume huge manpower and material resources and may also cause unnecessary interference and impact the daily operation of the station. In order to arrange the Guidance Signage System more accurately, this study proposes a multi-software simulation of the proposed method for setting up the spatial location of the Guidance Signage System, which consists of several steps (Figure 11).

Compared with the existing research results [8,9,45], it can be found that although several studies have emphasized the role of the Guidance Signage System in transportation hubs to enhance wayfinding and guidance efficiency, this study is significantly innovative in several aspects. Fei Peng and Zhihua Xiong [8,9] focused on the relationship between the design of the Guidance Signage System and traffic flow in transportation hubs, usually through simulations or questionnaires to evaluate the effectiveness of passenger guidance. Most of these studies have focused on single-function spaces or simple transportation environments and have not explored the signage design in multifunctional and high-density environments in depth. In contrast, our study analyzes the signage layout of multiple articulated spaces in TOD stations by combining software tools such as Depthmap10 and Massmotion11.5 field tests with eye-tracking technology, which provides more accurate and objective data support. Unlike the methodology in Shao’s study [45], which relied heavily on traditional design criteria or simulation analysis to explore the effectiveness of the Guidance Signage System, this study examined the effectiveness of the Guidance Signage System through specific spatial scenarios. This study also analyzed the effects of different signage placement locations on the visual saliency of passengers through experiments in specific spatial scenarios. This study combines Depthmap, Massmotion, eye-tracking technology, and other means of analysis, and proposes an all-around analysis method from spatial layout to visual perception. Moreover, in the design of the spatial location of the Guidance Signage System, the visual field of the Guidance Signage System overlaps with the visual perception of the pedestrians, which helps the design of the Guidance Signage System in the connecting space of the TOD station to construct a scientific and reasonable design of the layout at the design stage.

3.3. Limitations and Future Research

There are some limitations to this study. The study did not fully consider the differences in individual characteristics of the subjects, such as the fact that there may be significant differences in visual attention and signage recognition among passengers of different ages, genders, or cultural backgrounds. Future research could explore the responses of different populations to the signage system from the perspective of individual characteristics, which would help provide more personalized guidance for signage system design. In addition, this study ignored the effects of sign color, size, and the surrounding environment when analyzing the effects of the sign system location on the visual salience of pedestrians. The color contrast, size, and environmental conditions of signs can have a significant effect on visual attention; therefore, future research needs to consider the combined effects of these factors in order to optimize signage design. On the other hand, the influence of environmental factors on the effectiveness of signage systems was not fully explored in this study. External conditions such as light and noise may affect sign visibility and passengers’ visual responses, and future research should consider how these environmental factors interact with sign design to further improve sign visibility and navigation. By addressing these limitations, future research can not only further improve the design of signage systems but also provide a more comprehensive and flexible solution for signage optimization in transportation hubs, which will promote the efficiency of the transportation system and user experience.

4. Conclusions

This study investigates the visual salience of the Guidance Signage System in different spatial modes of articulation and its impact on passenger wayfinding behavior through the combined use of Depthmap10, Massmotion11.5 software, and eye-tracking technology. The results show that the spatial location of the Guidance Signage System affects its visual attractiveness and wayfinding efficiency to a certain extent. In key connecting spaces, such as passageway bifurcations, atrium entrances, and entrances to sunken plazas, the optimal placement of the Guidance Signage System varies according to the characteristics of the space, presenting a variety of design strategies. These findings not only verify the hypotheses proposed in this paper but also provide an empirical basis for the refinement and scientific design of the spatial Guidance Signage System in the connecting space of TOD stations. This study initially proposes a spatial location design method for the Guidance Signage System in the interface space of TOD stations based on multi-software analysis and clearly points out that the layout of the Guidance Signage System can be optimized to enhance the wayfinding efficiency and traveling experience of passengers, promote the smooth flow of passenger traffic in stations, and improve the operational efficiency and service quality of the whole transport system. Future research can explore the effects of different Guidance Signage System types, colors, sizes, and other factors on visual saliency in order to enhance the practicality and universality of the study.