Assessment of Walkability of Large Parking Lots on University Campuses Using Walking Infrastructure and User Behavior as an Assessment Method for Promoting Sustainability

Abstract

Car-dominated university campuses allocate large areas of land for parking lots, which are major hubs for users to start and end their daily walking trips. However, studies on the walkability of large parking lots are limited, and there is a study gap in the assessment of existing constructed walking infrastructures and their usage and effectiveness in facilitating walking. In this study, a method is developed that can assess both the walking infrastructure and its usage, then applied in five large campus parking lots based on observational strategies. The results indicate that the orientation of a walking path perpendicular to a destination (which provides short-distance walks), availability of proper access to walking paths and designated crossing areas that connect between walking paths, proper implementation of effective traffic calming strategies, and presence of a single entrance and exit for vehicles all play important roles in promoting the use of existing walking infrastructure and creating pedestrian-friendly parking lots. Additionally, this study method extends the walkability assessment of built environments, particularly in large parking lots. This study promotes the creation of sustainable university campuses, thereby enhancing the quality of life of students and staff who use the facilities.

1. Introduction

Large university campuses are among the most dynamic places in cities, as they accommodate a large population of users, including students, faculty members, and other employees [1,2]. On car-dominated campuses, a significant number of users travel to and from campuses using private cars [3,4], because free parking lots act as magnets for those who travel by car [5]. In particular, large parking lots have become major hubs for commuters who use cars to start and end their daily walking trips [6]; therefore, these spaces have become one of the riskiest locations for pedestrian traffic accidents on university campuses [7,8]. This is a major issue that affects the sustainability and quality of life of a large number of campus users.

Walking, followed by cycling, has been recognized as the most sustainable mode of transportation within university campuses [9]. Several previous studies [10,11] have linked the enhancement of pedestrian accessibility and safety in urban areas with improved quality of life. Poor access to pedestrian infrastructure in large campus parking lots forces pedestrians to walk in parking aisles, exposing themselves to an increased risk of road traffic injuries [6]. Moreover, vaguely defined pedestrian infrastructure in parking lots can lead to pedestrian traffic accidents, because generally, car drivers do not look out for pedestrians when such facilities are absent or not easily visible [12], as they are usually distracted looking for parking spots [13]. Therefore, in this study, we highlight the importance of accessible and safe pedestrian infrastructure in parking lots as a way to improve the sustainability of and quality of life in university campuses.

In this study, we assessed walkability on university campuses that had large parking lots. We developed a novel assessment method and applied it in five large campus parking lots, all of which had different layouts, at the King Abdulaziz University (KAU) in Saudi Arabia. Thus, in this study, “large parking lots” are defined as those that require users to walk long distances and cross several parking aisles before reaching their desired destinations (Figure 1).

The significance of this study lies in extending the literature on walkability in large campus parking lots which cover significant land areas of car-dominated university campuses, and in developing the related assessment methods. More specifically, this study can contribute to the improvement of campus sustainability and the quality of life in universities by turning parking lots into pedestrian-friendly open spaces.

2. Literature Review

2.1. Importance of Walking Infrastructure in Developing Sustainable Campuses and Improving Users’ Quality of Life

Walking is known to be the most sustainable mode of transportation on university campuses [9]. The continuity and safety of walking paths are considered to be important factors that encourage users to walk on university campuses. Additionally, several factors, such as the quality of pavement, width of walking paths, quality of crossing areas connected to walking paths, availability of shading elements, and installation of pedestrian signs, are perceived as important, as they affect the efficiency of walking on campus [14].

In general, university campuses in cities include several types of urban open spaces, such as squares, plazas, walkways, green areas, and large parking lots. Satisfaction with the quality of these urban spaces positively affects users’ quality of life [15]. Campus sustainability is primarily linked to three factors: ease of movement, accessibility, and quality of the public realm. Interestingly, creating high-quality constructed urban open spaces is linked to enhancement of quality of life, social equity, and sense of place for campus communities [16].

Thus, improving the walking infrastructure in campus parking lots is vital for ensuring campus sustainability and enhancing users’ quality of life, as parking facilities are among the top pedestrian accident hotspots on university campuses [8]. This is because drivers tend to select parking spaces near their destinations. However, if they cannot find empty spaces, they continue to cruise until they find parking spaces close to their destination, resulting in excess CO₂ emissions and traffic congestion [17]. Thus, it is necessary to improve the walking infrastructure in campus parking lots in order to create a pedestrian-friendly environment that encourages walking.

2.2. Behaviors of Pedestrians and Drivers in Parking Lots

Non-use of walking paths is affected by pedestrian behavior when parking farther away from the destination. In this situation, pedestrians walk in a diagonal or semi-diagonal path across the parking lot to reach their desired destinations. The same behavior occurs in parking lots that have pedestrian-friendly infrastructure, as pedestrians tend to select the shortest distance to the destination [18]. This is because walking directly to a desired destination by selecting the shortest route is a natural response [19]. However, pedestrians tend to use designated walkways when they are oriented in the direction of their destination in a way that provides the shortest walking distance [18]. The use of campus walkways is conditioned on having proper accessibility and surfaces to walk on while ensuring that walkways are relatively wide and free of obstacles [14].

Designated crossing areas draw drivers’ attention and alert them to pedestrians crossing parking aisles, thus, creating safer crossings [12]. On the other hand, unmarked crossing areas are considered ineffective in influencing the behavior of non-compliant drivers [18]. This is because providing crosswalk markings in conjunction with pedestrian crossing signs while implementing other measures can alert drivers that they are approaching a designated pedestrian crossing area [20]. Furthermore, providing curb cuts to connect crossing areas to raised walking paths can ease pedestrian accessibility [21] and enhance safety. Providing sufficient lighting in such areas can also enhance pedestrian use and safety, particularly while walking at night [22]. Additionally, implementing effective traffic calming strategies (TCS) within parking lot areas is important, as most drivers do not obey the stop signs, markers, and speed limits in parking lots [18].

2.3. Previous Studies Assessing the Walkability of Campus Parking Lots

Currently, there are limited studies assessing the walkability of parking lots, particularly when compared with the number of studies that have evaluated the walkability of residential areas and main streets.

Bezerra et al. [23] presented a feasible and low-budget framework for conducting an infrastructure risk analysis for pedestrians in a university campus parking facility. The study proposed a checklist for the main infrastructure elements that may create a risk for pedestrians in parking lots. These elements were investigated using 23 questions classified into three domains: parking layout, pavement and drainage, and availability of provision for pedestrians. The importance of the study stems from its checklist, which identifies vulnerable points for the assessment of pedestrian infrastructure in parking lots.

In other previous studies, scholars have assessed the walkability of parking lots without providing a comprehensive assessment of the walking infrastructure or its usage. For example, Alhajaj and Daghistani [6] developed a method containing 10 investigation items for assessing the accessibility and safety of university students’ walking routes on car-dominated campuses. Their method was based on four physical zones that constituted a typical student’s (car user) walking route: off-street parking, the sidewalk on the parking side, crossing areas, and the sidewalk on the destination side. The significance of this study can be attributed to its assessment of walking in the off-street parking zone through two items: an accessibility item (availability of designated walking paths in the parking area) and a safety item (availability of effective TCS, such as speed tables, in the parking area). Both of these items were assessed using field observations and student questionnaires.

Fotino [24] studied the walkability of three inner-city university campuses in Southern Ontario containing pedestrian streets. The study used a previously developed walkability audit tool consisting of 36 investigation items to evaluate the physical design elements of streets that influence walking. Notably, the audit tool incorporated a “Road Attributes” section that investigated two items: (1) the number of entrance and exit points of parking lots and garages that intersect the streets’ sidewalks, and (2) the tendency of pedestrians to walk through parking lots to reach most campus buildings.

Wogalter [25] investigated pedestrian trips and falls in parking lots caused by wheel stops. In the study, Wogalter discussed factors related to visual obstruction, attention, salience, and expectancy. He provided an alternative hazard control analysis, along with solutions to limit the risks associated with pedestrian trips and falls in such areas. Although the study did not consider parking lots on university campuses, it focused on a common physical element used in most parking lots in cities and urban spaces, including university campuses. Wheel stops are widely used in parking lots to control vehicle movement, organize parking, and protect designated pedestrian walking areas from encroachment by cars.

Table 1. Previous studies that assessed the walkability of parking lots.

Studied Part of the Parking Lot	Walkability Domain	Method	Study
Connectivity of sidewalks adjacent to a parking lot Walking accessibility to building entrances through parking lots	Continuity Accessibility	Audit tool (completed through field observations)	Fotino [24]
Parking layouts Parking surfaces Stormwater drainage Designated pedestrian areas	Accessibility Safety Parking facilities	Checklist (completed through field observations)	Bezerra et al. [23]
Parking bay surface obstructions (wheel stops)	Safety	Forensic human factors and ergonomics analysis	Wogalter [25]
Availability of walking paths inside parking lots and their linkage to the adjoining sidewalk located at the parking parameters Availability of traffic calming strategies (TCS)	Accessibility Safety	Walking route checklist (completed through field observations) Student perception questionnaire	Alhajaj and Daghistani [6]

provides a summary of the aspects of parking lot walkability assessed in previous studies.

However, all of these previous studies have several limitations. First, they did not investigate the appropriateness of parking lot surface quality for walking; this is important because parking spaces are considered the starting area for walking after parking cars. Second, they did not investigate whether appropriate access points were frequently provided along the parking rows to convey parking users to walking paths (located between bumpers) easily and safely after parking their cars. Third, none of these studies examined the continuity of walking paths when they intersect parking drive aisles. Fourth, they did not investigate whether the parking lot destination edges provided well-defined, controlled, and obvious access areas for pedestrians to exit or enter the parking space, which could prevent potential pedestrian traffic accidents. Finally, these studies did not comprehensively assess the walking infrastructure in parking lots or investigate its appropriateness and effectiveness by assessing pedestrian and driver behaviors. Therefore, the present study addresses these abovementioned limitations in the existing literature and extends current knowledge by developing a method that comprehensively and systematically assesses both the existing walking infrastructure and its usage in campus parking lots, then applies it to assess different large parking lots on a university campus.

3. Materials and Methods

3.1. Study Area

For this study, we selected five parking lots at KAU that had walking infrastructure and different physical layouts (Figure 2). We selected the KAU campus because it accommodates a large number of full-time students (~77,356) [26] and includes several large parking lots which experience frequent pedestrian–traffic conflicts (

Table 2. Information on the five parking lots considered in this study.

Parking Lot	Parking Capacity	Length of Drive Aisles	Number of Parking Rows	Parking Entrance and Exit
a	323	50–62 m	13	Single: same spot
b	216	17–90 m	16	Single: different spots
c	140	17–96 m	4	Single: different spots
d	190	55–89 m	9	Multiple
e	468	17–212 m	24	Multiple

). Figure 3 portrays the different elements of the five parking lots.

3.2. Method

The method developed in this study was primarily based on observational strategies and consisted of two steps. The first step involved assessment of the walking infrastructures of the five campus parking lots using the developed Parking Walking Infrastructure Checklist (PWIC). The second step involved assessment of the way in which pedestrians used the existing walking infrastructure in the parking lots and whether the infrastructure was effective in creating a pedestrian-friendly environment in the presence of drivers, for which we used the developed Pedestrian and Driver Behaviors Record (PDBR). The results of the PWIC assessments were then compared with those obtained of the PDBR assessments to create a meaningful discussion (Figure 4).

3.3. Parking Walking Infrastructure Checklist (PWIC) and Pedestrian and Driver Behaviors Record (PDBR) with Descriptions of Indicators

To comprehensively and systematically assess the walking infrastructure in large parking lots, we developed the PWIC with 15 indicators: parking row surface quality, walking path availability, separation, orientation, accessibility, obstructions, walking path quality, width of walking paths, designated crossing area availability, availability of curb cuts, TCS, pedestrian directional signs, speed signs, availability of designed access areas leading to destinations outside the parking lots, and lighting (

Table 3. Description of indicators according to the Parking Walking Infrastructure Checklist (PWIC) developed in this study.

Indicator *	Walkability Domain	Description
1. Parking rows’ surface quality	Maintenance	This indicator was used to investigate if the parking rows’ surfaces were suitable for walking by being free of cracks, breaks, or potholes to ensure that users’ walkability was not affected after leaving their cars
2. Walking path availability [6,23,27,28]	Accessibility	This indicator was used to investigate if walking paths were provided, to ensure that the parking users can use them after parking their cars, to reach their destinations. Walking paths can be located in the middle between the bumpers of two parking rows, at both sides of the parking drive aisle, or at the periphery of a parking lot alongside a parking row
3. Walking path separation [13,18,27,28]	Safety	This indicator was used to investigate if walking paths were physically separated from the parking rows and parking drive aisles, using appropriate techniques, such as raising the walking paths level and using bollards, stoppers, or landscape buffers to prevent vehicles from crossing into the walking areas
4. Walking path orientation [28]	Accessibility	This indicator was used to investigate if the walking paths were placed perpendicular to the desired destination (perpendicular walking paths to a destination provide direct and short walking)
5. Walking path Accessibility [29]	Accessibility & Safety	This indicator was used to investigate whether the access point between parked cars was frequently provided to connect pedestrians (after parking the cars) to walking paths placed either at the periphery of a parking lot alongside a single parking row, or to the area in the middle of the bumpers of two parking rows. This is to improve pedestrians’ safety, so that they do not have to walk randomly between parked cars to enter or exit the walking paths
6. Walking path obstructions [28]	Accessibility	This indicator was used to investigate the presence of permeant vertical obstacles that obstruct a walking path, causing a reduction in its width and thus, affecting pedestrians’ walking areas. This included, but was not limited to, fire hydrants, lighting poles, signage posts, and tree pits. It can also include large tree branches that block walking zones and affect the pedestrians’ mobility
7. Walking path quality [23]	Maintenance	This indicator was used to investigate whether the surface of a walking path was suitable for walking, by checking for cracks, breaks, or potholes that could negatively affect walking
8. Walking path width [27]	Comfort	This indicator was used to investigate whether the walking path provided the standard minimum width (1.2 m) required for two pedestrians to walk at the same time
9. Designated crossing area availability [28]	Safety and Connectivity	This indicator was used to investigate whether the parking lot was provided with clearly marked designated crossing areas (e.g., colored, bricks) and pedestrian crossing signs to enhance the pedestrians’ crossing safety
10. Availability of curb cuts (Ramps) [23,27]	Comfort and Connectivity	This indicator was used to investigate whether the walking paths were provided with curb cuts, if they were constructed higher than the parking lot’s surface level. Curb cuts play an important role in making walking comfortable when moving from one level to another and enhance connectivity if they are provided on both sides of a walking path separated by a pedestrian designated crossing area
11. Traffic calming strategies (TCS) [6,28]	Safety	This indicator was used to investigate whether the parking lot was provided with effective TCS, such as speed pumps and tables, to improve pedestrians’ safety while walking in parking lots
12. Pedestrian direction signs	Accessibility	This indicator was used to investigate whether the parking lot was provided with directional signs to assist pedestrians to find their way easily and ensure better use of walking paths
13. Speed signs [30]	Safety	This indicator was used to investigate whether the parking lot was provided with a speed sign in good condition and check if the sign was placed in an obvious area, to inform parking lots users of the allowed speed limit, to enhance the safety of pedestrians. In ideal situations, speed signs should be placed near each parking lot entrances
14. Availability of designed access-areas to destinations outside parking lots	Accessibility and Safety	This indicator was used to investigate whether the parking lot’s destination edge was provided with a designated access area(s), to convey pedestrians from the parking to the desired destination (such as classrooms, plazas, and vice versa). An access area must be clearly defined (minimum width of 3 m [31]) to pedestrians and drivers, to prevent exiting or entering a parking lot through walking randomly between parked cars along the periphery, causing potential pedestrians traffic accidents
15. Lighting [23,27,28]	Safety	This indicator was used to investigate whether sufficient lighting was provided to all parts of a parking lot: (1) parking spaces; (2) walking paths; (3) designated crossing areas; and (4) access areas. Lighting is important, as it allows both pedestrians and drivers to be seen by each other and thus, reduce potential pedestrian traffic accidents. It is also a vital element in the parking lots of university campuses, which are active at night

* Indicators with no corresponding references were newly created.

); the assessment of each indicator is explained in

Table 4. Levels of indicators used in the Parking Walking Infrastructure Checklist (PWIC) developed in this study.

Indicator	Level
	Poor 1 Point	Low 2 Points	Medium 3 Points	High 4 Points
1. Parking rows’ surface quality	Almost all unsuitable for walking	Some suitable for walking	Mostly suitable for walking	Almost all suitable for walking
2. Walking path availability	One walking path for the entire parking lot	Some parking rows had walking paths	Most parking rows had walking paths	All parking rows had walking paths
3. Walking path separation	Unseparated	Some of them were separated	Mostly separated	All separated
4. Walking path orientation	All parallel to the destination	Few were perpendicular to the destination	Some were perpendicular to the destination	Mostly perpendicular to the destination
5. Walking path accessibility *	Access through walking between parked cars	Some walking paths were provided with access paths	Most walking paths were provided with access paths	All walking paths were provided with access paths, OR not applicable (in case walking paths were placed at both sides of parking drive aisles)
6. Walking path obstructions *	>5 obstructions	4–5 obstructions	2–3 obstructions	0–1 obstruction
7. Walking path quality *	Several cracks/potholes	Some cracks/potholes	Few cracks/potholes	No cracks/potholes
8. Walking path width	Widths of all paths < 1.2 m	Widths of some paths ≥ 1.2 m	Widths of most paths ≥ 1.2 m	Widths of all paths ≥ 1.2 m
9. Designated crossing area availability	Not available	Available in some intersections, with either pedestrian crossing signs, or clearly marked surfaces	Available in some intersections, with both pedestrian’s crossing signs and clearly marked surfaces	Available in all intersections, with both pedestrian’s crossing signs and clearly marked surfaces
10. Availability of curb cuts (Ramps)	Not available	Available in few intersections	Available in some intersections	Available in all intersections
11. Traffic calming strategies (TCS)	Not available	Available in some parking drive aisles	Available in most parking drive aisles	Available in all parking drive aisles
12. Pedestrian direction signs	Not available	Available in some parking drive aisles	Available in most parking drive aisles	Available in all parking drive aisles
13. Speed signs **	Not available	Available, but placed in an area not clear to drivers and poorly maintained	Available, but either placed in an area not clear to drivers, or poorly maintained	Available, in a good condition and placed in areas obvious to drivers
14. Availability of designed access-areas to destinations outside parking lots	Not designed and completely blocked by parking spaces	Partially blocked by parking spaces and/or not connected to the parking by marked crossing, with the path width being <3 m	Not blocked by parking spaces, but either not connected to the parking by marked crossing, or the path width was <3 m	Not blocked by parking spaces, connected to the parking by marked crossing, and widths of paths were ≥3 m
15. Lighting	Unavailable, or cover very limited area	Cover some areas	Cover most areas	Cover all areas

* Measured for segments every 30 m. ** Measured per parking entrance.

. These indicators were based on an intensive review of pedestrian facilities and parking design standards, walkability audit tools, and items or indicators adopted in previous studies that assessed the walkability of parking lots.

In the PDBR, we developed seven indicators to assess the behaviors of pedestrians and drivers when using the parking lots. These seven indicators were: pedestrian use of walking paths, pedestrians’ continuity in using walking paths, pedestrian use of designated crossing areas, pedestrian use of access areas, drivers not speeding, drivers giving way to pedestrians at designated crossing areas, and drivers giving way to pedestrians crossing drive aisles (

Table 5. Description of indicators according to the Pedestrian and Driver Behaviors Record (PDBR) developed in this study.

Indicator *	Description
1. Pedestrians used abutting walking paths ** [18]	40 pedestrians were observed if they use directly the available abutting walking paths after parking their cars to reach their desired destinations
2. Pedestrians’ continuity to use walking paths	This indicator was investigated the tendency of the same 40 pedestrians observed in Indicator 1 to continue using the walking paths. We only recorded the number of pedestrians that continued to use the walking paths (after parking their cars and use directly the abutting walking paths) until they arrived at their desired destinations. This included staying on the same used walking path, until they reached their destinations, or reusing alternate walking paths after crossing one or more parking drive aisles
3. Pedestrians used designated crossing areas [18]	This indicator also investigated the same 40 pedestrians that were observed in Indicator 1 (both used or unused abutting paths) if they were obliged to cross from the designated areas
4. Pedestrians used the access area(s)	Similarly, this indicator investigated the same 40 pedestrians that were observed in Indicator 1 (both used or unused abutting paths) if they were obliged to exit or enter the parking lot using the designated access areas
5. Drivers did not speed ** [18,32]	20 drivers’ behavior at different parking drive aisles were observed and those who were speeding (>20 km/h) were recorded
6. Drivers gave way to pedestrians at designated crossing areas ** [18,32]	20 drivers’ behavior at different designated crossing areas were observed and the number of drivers who did not give way to pedestrians was recorded
7. Drivers gave way to pedestrians crossing drive aisles **	20 drivers’ behavior at different parking drive aisles were observed and the number of drivers who did not gave way to pedestrians who were crossing the drive aisles was recorded

* Indicators with no corresponding references were newly created. ** Randomly selected samples from different spots per parking lot.

). The assessment of each indicator is explained in

Table 6. Levels of indicators in the Pedestrian and Driver Behaviors Record (PDBR).

Indicator	Level
	Low 1 Point	Medium 2 Points	High 3 Points
1. Pedestrians used abutting walking paths *	<20	20–30	>30
2. Pedestrians’ continuity to use walking paths *	<20	20–30	>30
3. Pedestrians used designated crossing areas *	<20, OR rated low, if designated crossing areas were not available	20–30	>30
4. Pedestrians used the access area(s) *	<20	20–30	>30
5. Drivers did not speed **	<15	15–17	≥18
6. Drivers gave way to pedestrians at designated crossing areas **	<15, OR rated low, if designated crossing areas were not available	15–17	≥18
7. Drivers gave way to pedestrians crossing drive aisles **	<15	15–17	≥18

* Measured as 40 pedestrians per parking lot. ** Measured as 20 vehicles per indicator in each parking lot.

.

For indicators related to pedestrian behavior, we conducted field observations and recorded the behavior of 40 pedestrians, who were randomly selected at each parking lot, in the first four indicators. During the data collection process, we ensured that the pedestrians did not notice that they were being observed. For indicators related to driver behavior, we applied the same procedure to record the behavior of 20 drivers for each indicator (Indicators 5, 6, and 7) in each parking lot. All the observations were conducted on several weekdays during the high-use period (9:00–11:00 h) in fine/regular conditions. The reason for selecting a total of 40 pedestrians and 20 drivers (per indictor related to drivers) in each parking lot was to keep the process of data collection simple, convenient, fast, and cost effective. The selected samples reflect the behaviors of most parking users, as we considered different locations in each parking lot. The selection of a small sample size has been used in previous studies; for example, Shaaban [32] selected 10 vehicles per location, when studying the behaviors of drivers toward pedestrians in 10 arterial neighborhood streets.

Notably, we used the combination of a four-point scale (to assess the PWIC indicators) and a three-point scale (to assess the PDBR indicators). The adoption of different rating scales offered flexibility in choosing the most appropriate scale for each tool. We chose a three-point scale because it was easier, quicker, and more appropriate for assessing the PDBR indicators, which only required counting the number of pedestrians and cars using the parking lots in different settings. On the other hand, we used a four-point scale to provide a more precise assessment of the PWIC indicators, which involved investigating the various elements and qualities of the parking lot walking infrastructure. The selection of different rating scales to assess the walkability of urban environments has been considered effective as applied in several previous studies and audit tools [32,33,34].

3.4. Calculation of Overall Ratings for All the Parking Lots

We calculated an average rating for both the PWIC and PDBR to obtain a comprehensive assessment for each parking lot using the following equation:

$$\mathrm{Average}\mathrm{parking}\mathrm{rating}=\left[In1+In2+\dots +Inn\right]/n$$

where In1, In2, and Inn are the respective assessment scores of the first, second, and last indicators in PWIC or PDBR and n is the total number of indicators, which was 15 in PWIC and 7 in PDBR.

4. Results

4.1. Parking Walking Infrastructure Checklist (PWIC) and Pedestrian and Driver Behaviors Record (PDBR) Indicator Ratings

Table 7. Ratings for the indicators of the Parking Walking Infrastructure Checklist (PWIC) for the five parking lots (A–E).

Indicator		Parking Lot A		Parking Lot B		Parking Lot C		Parking Lot D		Parking Lot E
		Point *	%	Point *	%	Point *	%	Point *	%	Point *	%
1	Parking rows’ surface quality	3	75%	4	100%	3	75%	3	75%	3	75%
2	Walking path availability	3	75%	3	75%	4	100%	4	100%	4	100%
3	Walking path separation	4	100%	4	100%	4	100%	4	100%	4	100%
4	Walking path orientation	2	50%	3	75%	4	100%	2	50%	3	75%
5	Walking path accessibility	1	25%	2	50%	1	25%	1	25%	1	25%
6	Walking path obstructions	2	50%	4	100%	3	75%	3	75%	3	75%
7	Walking path quality	4	100%	4	100%	4	100%	4	100%	4	100%
8	Walking path width	2	50%	3	75%	4	100%	3	75%	3	75%
9	Designated crossing area availability	2	50%	1	25%	2	50%	2	50%	2	50%
10	Availability of curb cuts (Ramps)	2	50%	1	25%	1	25%	1	25%	1	25%
11	Traffic calming strategies (TCS)	1	25%	1	25%	1	25%	1	25%	1	25%
12	Pedestrian direction signs	1	25%	1	25%	1	25%	1	25%	1	25%
13	Speed signs	1	25%	1	25%	4	100%	2	50%	2	50%
14	Availability of designed access-areas to destinations outside parking lots	4	100%	3	75%	4	100%	2	50%	2	50%
15	Lighting	2	50%	2	50%	4	100%	3	75%	2	50%
Average (out of 4 points)		2.3	58%	2.5	63%	2.9	73%	2.4	60%	2.4	60%

* The rating was provided based on a four-point scale.

summarizes the ratings of the 15 PWIC indicators for the five parking lots considered in this study, whereas

Table 8. Ratings for the indicators of the Pedestrian and Driver Behaviors Record (PDBR) for the five parking lots (A–E).

Indicator		Parking Lot A		Parking Lot B		Parking Lot C		Parking Lot D		Parking Lot E
		Point *	%	Point *	%	Point *	%	Point *	%	Point *	%
1	Pedestrians used abutting walking paths	1	33%	1	33%	2	67%	1	33%	1	33%
2	Pedestrians’ continuity to use walking paths	1	33%	1	33%	2	67%	1	33%	1	33%
3	Pedestrians used designated crossing areas	2	67%	1	33%	3	100%	1	33%	1	33%
4	Pedestrians used the access area(s)	3	100%	3	100%	3	100%	3	100%	2	67%
Average rating for pedestrian behavior (out of 3 points)		1.8	60%	1.5	50%	2.5	83%	1.5	50%	1.3	43%
5	Drivers did not speed	2	67%	2	67%	2	67%	1	33%	1	33%
6	Drivers gave way to pedestrians at designated crossing areas	2	67%	1	33%	2	67%	1	33%	1	33%
7	Drivers gave way to pedestrians crossing drive aisles	2	67%	2	67%	2	67%	1	33%	1	33%
Average rating for driver behavior (out of 3 points)		2	67%	1.7	57%	2	67%	1	33%	1	33%
Overall average (out of 3 points)		1.9	63%	1.6	53%	2.3	77%	1.1	37%	1.1	37%

* The rating was provided based on a three-point scale.

presents the ratings of the seven PDBR indicators. Figure 5 illustrates the distribution of pedestrians (samples) in each assessed parking lot. As shown in Figure 6, we compared the total PWIC ratings with those of the PDBR for each parking lot. The five parking lots are hereinafter referred to A–E.

The PWIC-related analysis revealed that C obtained the highest rating (2.9 out of 4), whereas A received the lowest rating (2.3 out of 4). The PDBR results indicate that C achieved the highest rating for pedestrian behavior (2.5 out of 3), whereas E obtained the lowest rating (1.3 out of 3). In terms of driver behavior, parking lots A and C achieved the highest ratings (2 out of 3), whereas parking lots D and E had the lowest ratings (1 out of 3).

4.2. Descriptive Analysis

Indicator 1 in the PDBR shows that <20 of pedestrians used the abutting walking paths in each of the four parking lots A, B, D, and E; this is despite Indicator 1 in the PWIC (parking row surface quality) being mostly rated medium (75%) in four parking lots and Indicator 2 (walking path availability) being rated medium (75%) in parking lots A and B and high (100%) in parking lots C, D, and E. Other indicators (3 and 7 in the PWIC) relating to walking path separation and quality were rated high (100%) in all the parking lots. Here, pedestrian behavior was negatively affected by three main factors. The first was the orientation of walking paths (Indicator 4 in the PWIC), rated low to medium (50–75%) in all the parking lots except parking lot C. Placing walking paths parallel to the desired destination decreased the functionality of the walking paths, as the pedestrians selected the shortest walking route to their destinations, a natural response confirmed in the literature [18,19]. The second was the unavailability of walking path accessibility in most parking lots, as highlighted by Indicator 5 of the PWIC, which implies a benefit of providing frequent access points to walking paths placed either between bumpers or at the periphery of a parking lot alongside a parking row. After parking their cars, most pedestrians preferred walking at the sides of the parallel drive aisles to their destination until they reached a perpendicular aisle to their destination; they found it uncomfortable to walk between parked cars to reach the walking paths between the bumpers. This lack of access points also affected pedestrians’ ability to reach walking paths placed perpendicular to the desired destinations, as indicated by the rating of Indicator 1 in the PDBR for parking lot C. The problem of accessibility to walking paths between bumpers increased due to the lack of curb cuts (Indicator 10 in the PWIC) in most parking lots, as all existing walking paths were raised. Curb cuts are known to be important in easing walking accessibility and enhancing pedestrian safety [21]. The third factor was the poor to low rating of Indicator 9 in the PWIC (availability of designated crossing areas). The lack of crossing facilities led to existing walking paths being disconnected from each other, and this problem was magnified by the lack of direction signs (for pedestrians) in all the studied parking lots (Indicator 12 in the PWIC). Crossing facilities can work as a physical guide in large parking lots, leading pedestrians to the next part of a walking path when the path is disconnected by a traffic lane or intersection. Therefore, the overall low rating of Indicator 1 in the PDBR negatively affected the rating of Indicator 2 in the PDBR (pedestrians’ continuity to use walking paths), as it depended on the same users who used the abutting walking paths after parking their cars directly.

Indicator 3 in the PDBR (pedestrians used designated crossing areas) showed that <20 of pedestrians used the designated crossing areas in each of parking lots B, D, and E; this may be due to the unavailability or limited number of crossing areas, as they were rated 1 (25%), 2 (50%), and 2 (50%) out of 4, respectively, on Indicator 9 of the PWIC. For this reason, Indicator 6 of the PDBR (drivers gave way to pedestrians at designated crossing areas) portrayed low ratings (33%) in these three parking lots. In contrast, parking lot C was rated high (100%) (Indicator 3 in the PDBR), as most pedestrians used the facility, although the assessment of this parking lot was rated low (50%) (Indicator 9 in the PWIC). This can be attributed to two factors: first, due to the relatively small size of the parking space (consisting of only four long parking rows), it was easy for pedestrians to notice the crossing facilities. Second, the crossing areas were linked to two out of four of the walking paths, placed perpendicular to the desired destinations, and the designated access point linked the pedestrians directly to their desired destinations outside the parking space.

Indicator 4 in the PDBR (pedestrians used the access areas) was rated high (100%) in all parking lots except parking lot E, which obtained a medium rating (67%). The high ratings seem to be logical for parking lots A and C, as they were both rated high (100%) for Indicator 14 in the PWIC, but contrasted with the ratings for parking D and E, which were rated low (50%) for the same indicator. Notably, landscape treatments such as hedges, concrete walls, and fences play an important role in defining access areas outside parking lots and forcing pedestrians to use them. The visibility of access areas to pedestrians and drivers is strengthened by not allowing parking on the periphery of the destination side, as well as by linking access areas to walking paths through clearly marked crossing areas, as implemented in parking lots A and C.

Indicator 5 in the PDBR (drivers did not speed) indicated that three parking lots (A, B, and C) obtained medium ratings (67%), while parking lots D and E were rated low (33%). When comparing these ratings with the assessments of the parking lots for Indicator 13 in the PWIC (speed signs), we observed that parking lots A and B obtained poor ratings (25%), as they did not provide such a speed-control element; parking lots D and E obtained low ratings (50%), while parking lot C obtained high ratings (100%). Speed signs may not be the only feature that plays an important role in reducing speed; other factors, such as having a small parking capacity (implying less space for driving) and single-car entry can help lower the driving speed inside parking lots. This issue can be further improved with the application of an effective TCS (Indicator 11 in the PWIC).

Indicator 6 in the PDBR (drivers gave way to pedestrians at designated crossing areas) showed that three parking lots (B, D, and E) were rated low (33%) while the remaining two (A and C) were rated medium (67%). As indicated previously, this problem was mainly due to the lack of such a facility, which was rated 1 (25%) to 2 (50%) out of 4 for Indicator 9 in the PWIC. Distinguishing walking paths and pedestrian crossing surfaces from the surfaces of parking driving aisles using different materials is important for pedestrian safety [35], as drivers are not likely to watch out for pedestrians when the walking paths and crossing areas are invisible [12].

Indicator 7 in the PDBR (drivers gave way to pedestrians crossing drive aisles) showed that none of the five parking lots were rated high; parking lots A, B, and C were rated medium (67%), while parking lots D and E obtained low ratings (33%). This was because none of the five parking lots provided any form of TCS, and were rated as poor (25%) on Indicator 11 of the PWIC. However, the low ratings of parking lots D and E on Indicator 7 in the PDBR was due to multiple entrances and exits in these lots, which encouraged the users to drive through to reach other areas of the campus. In addition, these parking lots had slightly wider drive aisles, which can lead to increased speeding. Thus, the availability of multiple parking entrances and exits and the presence of wide drive aisles in both parking lots amplified the issue of speeding, turning these parking lots into a passing area for cars to move from one spot to another area of the campus. Additionally, the presence of long parking rows/aisles, as observed in parking lot E, increased the speed of drivers inside the parking lots, confirming the results of previous studies [36]. Figure 7 presents examples of walking paths, designated crossing areas, and access areas to outside the parking lots from the studied parking lots.

5. Urban Design Strategies for Creating Effective Walking Infrastructure for Parking Lots

Current best practices highlight several guidelines and standards for designing the walking infrastructure of parking lots. For example, Toronto City Planning [28] highlights that large parking lots should be provided with several pedestrian paths. Path numbers, orientation, and width should be designed based on the expected flow of pedestrians through the site. Moreover, perpendicular access points to walking paths between bumpers must be provided [29]. Clearly marked crossings must be provided where pedestrian routes cross driving aisles [28,35]. Furthermore, providing effective TCSs (e.g., speed tables) should be considered to control traffic speed [28]. Other elements, such as lighting and curb ramps, are essential to increase safety as well as to enhance comfort and connectivity [27,28].

In this study, we recommend five essential urban design strategies based on the results of this study to improve current guidelines and standards for designing pedestrian infrastructure in parking lots. The first is to ensure the availability of walking paths that provide the shortest walking distance to the desired destination, promoting usage while designing walking pathways that are continuous and free of obstructions with appropriate surface quality and width. One way to achieve this is by placing walking paths, including parking rows, perpendicular to pedestrian destinations. In the event that perpendicular walking paths do not provide the shortest walking distance to the destination, then several diagonal paths should be created. In addition, opportunities to create an attractive walking environment should be explored by increasing greenery and providing resting points to achieve high usage. Second, creating diagonal access points to walking paths instead of perpendicular ones should be encouraged in order to improve the accessibility of walking paths and shorten the walking distance to destinations. This step should include the installation of curb cuts to ease access to all types of users if the walking paths are designed to be higher than the street level. The third recommendation is to ensure that pedestrian crossings are designed to strengthen the appearance of walking networks in parking lots in order to enhance pedestrian safety. This can be achieved through the use of different treatments (marked surfaces, pedestrian crossing signs, and pedestrian direction signs) in all spots where walking paths are disconnected by traffic lanes or intersections, ensuring the continuous usage of walking paths. This is a very important step, as users who park their cars in the middle parking spaces of large parking lots are unlikely to recognize whether the parking lot has a walking path network without considering such a treatment. Fourth, in addition to using conventional forms of TCSs such as speed tables or speed bumps, it is recommended that lane shifts and chicanes be applied in large parking lots to form S-shaped driving aisles that lower vehicle speeds. This step can be combined with the design of diagonal walking paths and designated safe crossing areas. Finally, parking lots’ destination edge should be designed in a way that ensures that pedestrians enter and exit the parking lot from defined access areas; this can be achieved by, for example, planting hedges or installing raised planters. Then, these access areas must be connected with the walking paths of parking lots to enhance their use and improve pedestrian safety (Figure 8).

6. Discussion and Conclusions

In this study, we have developed a novel method for assessing the walkability of large parking lots on university campuses. We applied the method to assess the walking infrastructures of five large parking lots at the KAU. The results highlight five aspects that play an important role in promoting the use of existing walking infrastructure and creating pedestrian-friendly parking lots. These include the orientation of a walking path perpendicular to a destination (that provides short-distance walks), availability of proper access to walking paths, availability of designated crossing areas to connect different parts of walking paths, proper implementation of effective TCS, and the presence of a single entrance and exit. The results of this study can be considered valid for the following three reasons. First, data related to the developed PDBR was collected through observations during regular weekdays, reflecting everyday life in the studied university campus parking lots. Second, this study adopts observational strategies and methodology, which are widely applied in walkability assessments [6,24,32,34,37,38] because they are efficient in gaining insight into the character, performance, and use of places in the built environment that are already designed [39]. Third, this study’s results confirm the findings of previous studies, as indicated in the Descriptive Analysis section. Therefore, its results and recommendations can be used to inform future studies.

Improving the walking infrastructure quality and functionality of large parking lots can help to create sustainable university campuses. Large parking lots are typically surrounded by groups of buildings. With an effectively designed parking lot, pedestrian are able to walk from one destination to another by walking through parking lots, instead of walking along the periphery or between parked cars to reach their destinations. Additionally, several university campuses place large parking lots behind each other, resulting in a massive divided area allocated for parking. In this case, having an appropriately designed walking infrastructure in each parking lot can create a large walking network that can encourage walking behavior and reduce the users’ dependence on cars to move from one spot to another. Furthermore, improving walking conditions in large parking lots can improve users’ quality of life by reducing drivers’ tendency to look for parking bays closest to the desired destinations in order to avoid long walking distances and exposure to traffic risks, as discussed by Alhajaj [40], thereby promoting a healthier lifestyle. This point is substantial with regard to improving the sustainability of the campus and the quality of life of its users. This can minimize the car-cruising behavior of drivers and lead to fewer pedestrian traffic conflicts and less traffic congestion, eventually resulting in lower levels of air pollution, as discussed by Shoup [41].

The present study extends the current knowledge related to the walkability assessments in urban environments by focusing on the walkability of large parking lots, which has not been included in previous well-known walkability audit tools [34,37,38]. We used two steps to assess the walkability of five parking lots. First, we determined the fifteen indicators of the PWIC to assess the entire existing walking infrastructure of the five parking lots. The PWIC assesses important physical elements that are not included in previous walkability tools, e.g., the quality of the parking surface for walking (Indicator 1), orientation of the walking path with respect to the destination (Indicator 4), availability of appropriate access paths to reach a nearby walking path (Indicator 5), and the availability of designed access areas to reach destinations outside the parking lot (Indicator 14). Additionally, we used the PDBR’s seven indicators to assess the effectiveness of the walking infrastructure by assessing driver and pedestrian behavior when using the available walking infrastructure and to investigate whether the current infrastructure created a pedestrian-friendly environment in the presence of vehicles. This step provided a meaningful assessment perception that helped us to determine whether the existing walking infrastructure was effective for walking.

This study method provides a simplified way to assess the walkability of campuses that have large parking lots. The proposed method is cost-effective, as it is based on observation strategies. The method does not require the use of geographical information systems (GIS), which requires costly resources and skilled personnel [32], or surveys, which are generally considered cost-intensive and may not provide accurate information. Overall, our findings extend the literature [6,23,24] concerning the development of new methods and approaches to promote sustainable university campuses, with a focus on the importance of walking infrastructure in such spaces.

Our method can be used to investigate the effectiveness of the design of large parking lots in different urban areas, such as shopping centers and airports. Thus, transportation planners, urban designers, landscape architects, and other official bodies responsible for improving the sustainability of cities can adopt our method and benefit from this study’s findings to improve walking conditions in large parking lots, which continue to occupy considerable land areas in cities, making driving easier and walking more difficult and less rewarding.

In conclusion, this study makes three important contributions to the literature. First, it extends the current walkability assessments for urban environments, particularly large parking lots. Second, its findings extend the body of the literature concerning the development of sustainable university campuses by carrying out assessments of neglected spaces that cover a significant amount of land area. Finally, our study extends the literature on walkability assessment in the Saudi Arabian urban context. This study has one major limitation that needs to be addressed. The developed method excluded the investigation of specific infrastructure for users with disabilities. Thus, future research is required to extend this method’s comprehensiveness by including assessment of infrastructure for people with disabilities. In addition, it may be desirable to create a simplified version of the PWIC that could allow general users to participate in rating their walking experience in large parking lots.