Planting in Parking Lots to Improve Perceived Attractiveness and Security

Method

We collected 180 color slides of commercial and multifamily residential parking lots in Atlanta and Athens, Georgia. The lots varied in size, in the amount of vegetation present, in the number of cars parked in them, in property value, and in the level of maintenance of pavement, structures, and vegetation in and around the lots.

We showed the slides to 200 college students and groups. The students independently rated the scenes either for attractiveness or for their perception of how secure from criminal and antisocial conduct they would feel if they were using the parking lot shown in the slide.

We also rated 31 physical features of the slide scenes (Table 1). Some of the features were estimates of the amount of space occupied by cars, buildings, pavement, sky, and vegetation. We also rated the prominence of particular components such as billboards, overhead wires, and flowers. We used a rating of “prominence of landscape design” to distinguish between sites where plantings had been made according to an apparent plan and sites where trees, shrubs, and vines appeared to have sprung up naturally. We also assessed several features related to potential views of the lot from nearby structures and roads, including prominence of windows, visibility of streets, view distance (how far one could see into the site), and proximity of entrances. Other variables addressed the quality of the site more generally, such as the degree of maintenance of pavement, structures, and vegetation. A rating of the apparent rental value of the property was assigned, based partly on the site’s location within the metropolitan Atlanta area.

We used both correlation and regression statistics to determine the relationships among the physical features and the evaluations of attractiveness and safety. We used factor analysis to determine how the 31 features tended to cluster together; Table 1 shows the nine clusters that emerged in that analysis.

Results

Attractiveness and security were related to a number of the physical features as shown in Table 1. Translated into more practical terms, our results indicate that the perceived security of the parking lots was greater when:

• Premises were landscaped with plant materials that were originally part of an overall landscape design, even a simple plan, and which continued to be maintained (shrubs pruned, weeds controlled, lawns mowed, dead material removed). Very high levels of unmanaged vegetation of the site tended to detract from security.

• The structures appeared to be easily accessible, whether commercial or residential; that is, the view of the front or street side of the structure, the structure was nearby, and entrances to the structure were highly visible.

• Surrounding property appeared to have high rental value, whether for commercial or residential purposes. Of course, high-quality landscaping and good maintenance practices contribute to the apparent property value of a site.

  The attractiveness of parking lots was enhanced when:

• The scene contained a large amount of well- maintained vegetation, and structures and pavements were less visible. In contrast to the security results, high levels of vegetation, whether managed or not, tended to increase attractiveness.

• The scene was of residential as opposed to commercial property.

• Surrounding property appeared to have high rental value, either for commercial or residential purposes.

One of our findings was that residential property in general fared better than commercial property. Residential lots tended to be smaller and to have more landscaping, whereas commercial lots were usually larger and often completely lacked vegetation. Commercial lots with some vegetation tended to have individual trees widely spaced in small planting areas across the lot, or to have a line of trees on the perimeter. More generous planting, especially garden areas around the structure, had proportionately greater power to enhance visual quality for commercial property.

Recommendations

Managers of urban commercial and multifamily residential properties range from small business people to real estate consultants advising corporations about their next franchise location, and from city foresters and arborists to planning and zoning commissioners. All these people as well as landscape architects have a common desire to provide settings that are safe and attractive for customers, potential residents, and visitors. The results of this study suggest several recommendations for using vegetation to improve both the attractiveness and perceived safety of urban parking areas.

1. Plant landscape materials according to a design, even a simple one, to enhance attractiveness yet not detract from perceived security. Select thin natural vegetation on a site to give the area a designed and maintained appearance (see Figure 1). Wholesale removal of vegetation is not required to promote the perception of safety.

2. On commercial properties, especially those with large parking lots, use foundation plantings or gardens immediately around the buildings to enhance the appearance of the entire parking lot. For greatest effect, use plantings on the lots as well. But see Recommendation 3 below.

3. To assure visibility of entrances, design plantings that define and emphasize the entrance, rather than reduce its visibility of and from the lot (see Figure 2).

4. Maintain pavement, structures, and vegetation. Provide for litter collection. When the site is undergoing development, maintenance requirements and costs should be considered in the design stage, to assure the upkeep of the premises.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1.

In and near parking lots, unmanaged vegetation reduces perceptions of security. Thinning the trees and clearing out undergrowth would enhance security while preserving the esthetic value of natural vegetation.

• Download figure
• Open in new tab
• Download powerpoint

Figure 2.

Highly visible entrances to buildings are reassuring to parking lot users. Vegetation can help define and locate the doors, but it should not interfere with the view from the lot to doorway or from the doorway into the lot.

Implementing these basic recommendations will promote both the attractiveness and security of urban parking lots.