Canadian Consulting Engineer

Parking Lots

May 1, 2006
By Mike Fenton

The vulnerability of parking areas to crime is widely recognized. A study by Liability Consultants of Sudbury, Massachusetts, for example, found that they are the leading location where a crime on a p...

The vulnerability of parking areas to crime is widely recognized. A study by Liability Consultants of Sudbury, Massachusetts, for example, found that they are the leading location where a crime on a property can lead to a lawsuit. The International Council for Shopping Centres recommends that mall security teams spend 60% or more of their time patrolling parking structures.

The combination of an environment rich in targets (unsupervised parked cars and isolated pedestrians) and relatively few witnesses attracts criminals to these areas. A parking structure that is poorly designed therefore not only increases the potential for crime but also makes the people who use the facilities feel unsafe.

Security experts rely on three types of measures for preventing situational crime. They are target hardening (e.g. using stronger doors); opportunity reduction; and Crime Prevention Through Environmental Design, or CPTED. The concept of CPTED is based largely on the works of authors Oscar Newman (Defensible Space, 1972), C. Ray Jeffery (Crime Prevention Through Environmental Design, 1971) and Jane Jacobs (The Life and Death of Great American Cities, 1969).

The premise of CPTED is that the built environment can be designed to reduce crime and the fear of crime. Its strategies include non-mechanical access control, boundary definition, clearly defined transition zones and natural surveillance. The most important deterrent according to CPTED is giving potential criminals the impression that they are always under observation.

To enhance this natural surveillance, the parking structure should be designed with few vision barriers. Levels should be as open as possible. Pillars are preferable to supporting walls. If a supporting wall is required between parking spaces, floor-to-ceiling openings will improve sight lines and reduce hiding places.

The parking structure should also be designed so that patrons can see either their destination or their vehicle at all times while walking to and from the building. So-called split levels where patrons have to walk up or down a half-level to reach the elevator or stairs are not advisable because they create vision restrictions.

Hiding places such as alcoves or recesses can be ambush hazards. If these corners cannot be avoided, they should be fenced off with materials such as chain link fencing or bars that patrons can see through.

To enhance surveillance, the stairwell doors, elevator lobby doors, and elevator lobby walls should incorporate as much glass as possible. For above-ground parking decks, designers should consider placing the stairwells on the building exterior and using glass panels for the outer walls.

Criminals like to prey on people who appear lost or confused. For this reason the parking lot design should incorporate large, highly visible wayfinding signage to mark elevators and stairwells.

Lighting No. 1 concern

Focus groups on parking lots routinely identify lighting as their number one security concern. In general, parking structure lighting should conform to the Illuminating Engineers Society of North America (IESNA) Standard RP-20. During the day garage ramp entrances require 500 lux, garage driving lanes measured 20 metres from the ramp (facing inwards) require 20 lux, and garage interiors (stalls and driving lanes) require 10 lux. At night the required light level for all three areas is 10 lux.

If closed-circuit television (CCTV) cameras are part of your security plan the lighting design will have to reflect this. Keep in mind that lighting requirements for colour CCTV cameras are different from those for black and white cameras. For example, low-pressure sodium and to a lesser degree high-pressure sodium luminaries do not provide suitable colour rendition for colour cameras. A white light source such as metal halide or incandescent is preferable.

The objectives of a lighting plan include meeting IESNA RP-20, reducing ambush hazards by eliminating areas of shadow and contrast, and providing even illumination throughout. The need for light from luminaries can be reduced by painting walls and ceilings gloss white and by applying light-reflective sealer to the pavement. It’s important to find the most light-reflective products for your parking structure. Tests can be done by applying small batches to the walls or pavement and using a light meter after the recommended drying time. Other light gains can be realized by specifying reflective white pipes instead of black ones, keeping black splash guards to only 8* tall verses the usual 24*, and by using lighter colours such as yellow rather than purple or brown as section identifiers.

Locks, cameras and other tools

Stairwells are used by criminals to discreetly move between parking levels. They can also use them as an escape route, and as a holding area for stolen property. Worse, a victim can be dragged into a stairwell and assaulted there. Stairwells that are not used on a regular basis should be secured with magnetic locks interfaced to the building fire alarm system. Magnetic locks on remote stairwells will also force intruders to move between levels in areas where they are more likely to be noticed.

Areas requiring CCTV camera coverage include stairwell doors, elevator lobbies, vehicle entrance doors and duress stations. Some general camera coverage will be required on every level, depending on what is practical and financially feasible.

From the perspective of providing forensic records, fixed cameras are preferable to pan tilt and zoom (ptz) cameras. Experience has shown that ptz cameras will most likely be aimed in the wrong direction when something happens (see Mary Lynn Garcia, Ph.D., The Design and Evaluation of Physical Protection Systems (Boston: Butterworth-Heinemann, 2001).

Almost all cameras sold today are solid state construction. These cameras are much less susceptible to image “burn in,” which occurs when a ghost image of a previous shot remains visible after the camera has been re-aimed. Burn-in was a major problem with tube cameras.

The effectiveness of cameras is enhanced with ceiling mount speakers and microphones in the parking levels. They allow staff to question people acting suspiciously. Control room staff can also conduct “sonic” patrols by using the microphones to listen for sounds such as screams or breaking glass.

Duress stations should be located so that patrons are never farther than 25 quick steps away from one. The stations are usually mounted about 4 feet above grade on a pillar or wall, and ideally in the centre of a fluorescent pink or chartreuse wall patch. Many duress stations are blue in colour. When a duress station is triggered a local alarm should sound and an alarm signal should be sent to a control room. They should also include intercoms for non-emergency situations such as when a patron cannot find their vehicle.

In general, parking lot security equipment and technology is much more sophisticated than it was even 10 years ago. Combining the new tools with a balanced, in-depth engineering approach will result in a parking structure that not only is safe, but almost as importantly, one that feels safe as well.

Mike Fenton, CPP, PSP is director of consulting and client support for Paragon Protection in Toronto. He is a Certified Protection Professional and Physical Security Professional with the American Society for Industrial Security. E-mail


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