Parking safety begins with the layout and design of the parking structure, and the key is visibility. High visibility within and from outside parking facilities can greatly reduce safety risks.
When laying out a parking facility, it is important to establish lines of sight between exits and parking areas. For example, if a pedestrian walks down an aisle and reaches a point where he or she must turn toward an elevator or stair tower, the person should be able to see both the elevator and his or her vehicle from that point.
By permitting patrons to maintain orientation within the structure, designers can avoid forcing them to wander within the garage, which in turn reduces the risk of people being struck by a vehicle or attacked by an intruder.
Maintaining this line of sight can be difficult, however, depending on the topography. For example, often designers are forced to slope the floor of a garage to compensate for a slope in the exterior landscape. Parking structures are typically constructed of multiple modules, which are placed side by side to create the garage. If the slope were placed in the center module of a three-module garage, it would be impossible to see from one side of the structure to the other across the modules.
When possible, architects should avoid placing the slope in the center module and should instead move it to one of the outermost sections, where one side of the garage is visible from outside the structure. This affords the parker greater safety, because in addition to being seen by passersby, daylight from the outside offers greater visibility and can somewhat compensate for the reduced safety inside the structure.
Elevator lobbies. Lobbies leading to elevators should include as much glass as possible to improve visibility within and from outside the structure. In addition, if possible, some part of the lobbies should face a public area, such as a street, to make them visible from the outside.
Additionally, the elevators themselves should include glass-backed shafts and glass cabs facing public areas. Glass permits others to see who is in the elevator, thus minimizing the risk of attacks.
Stairways. The same need for visibility holds true for stairways. In the past, fire codes required stairways to be entirely enclosed in masonry. Today, however, most codes permit as much glass as possible on the exterior side, away from the building. This code change allows the use of glass to enhance visibility.
Furthermore, many codes now permit completely open stairways on the outside of the building. Finally, the underside of stairways on the ground level should always be sealed off to eliminate a potential hiding place for attackers.
Spaces and aisles. Careful configuration of parking spaces and aisles reduces possible hiding places for criminals and enhances pedestrian space. Wider aisles provide more shared room for parkers, allowing pedestrians to walk down the center of the aisle when there is no traffic rather than directly adjacent to parked cars.
The main factor affecting aisle width is the degree of angle of parking spaces. The most efficient layout for 45 degree angle spaces has the narrowest aisles at approximately 12 feet. While this configuration maximizes space in small areas, it is not ideal for safety.
It is best to put parking spaces at 90 degree angles, because it results in driving aisles that are 24 to 26 feet wide, which allows parkers to walk to and from their vehicles without having to walk too close to parked cars.
Landscaping. While landscaping can enhance the appearance of the facility, care must be taken to ensure that it doesn’t create unsafe areas where people can hide. The safest approach is to avoid bushes, relying instead on low-profile shrubs that are spaced far enough apart from each other that they don’t create a visual blockade.
Lighting. Bright lighting is one of the most effective deterrents to both accidents and attacks. Today, most garages are designed with high lighting levels of at least 10 to 12 foot candles over parked cars and 15 to 20 foot candles in walking and drive aisles.
Public areas, such as lobbies and stairs and elevator towers, should feature even brighter lighting. For example, the lighting within 50 feet of stairs and elevators should be increased to 40 foot candles of light to create a brighter, safer area. This is particularly true in underground garages, where there is no natural supplemental light.
Entrances into parking structures should feature at least 60 foot candles of illumination to ease the transition from a bright exterior into the garage. That also helps to reduce blind spots.
It is also advisable to install high lighting levels to illuminate the exterior of the parking facility, particularly in areas that experience high pedestrian traffic, such as college campuses, hospital campuses, and downtown locations. As a rule, exterior lights should be placed approximately 12 feet above ground, and they should point downward to illuminate wide areas along the ground.
Another method for increasing visibility is to paint the walls of the structure white to reflect light. Lighting fixtures should also be strategically placed to bounce light off the walls and reduce dark corners where criminals could hide.