Step 4 - Countermeasures to protect the critical assets from the threats

Countermeasures are developed as a result of the general- and specific-design strategies. They commonly take the form of site-work, building/structure, detection, and procedural elements:

• Site-work elements include the area surrounding a facility or an asset. They can include perimeter barriers, landforms, and standoff distances.
• Building and structure elements are protective measures directly associated with facilities and structures. These elements include walls, doors, windows, and roofs.
• Detection elements detect such things as intruders, weapons, or explosives. They include closed-circuit television, motion detectors, alarms, and weapon and explosive detectors, including chemical and biological weapon detection technologies. These elements can also include the guards used to support this equipment or to perform similar functions.
• Procedural elements are the protective measures required by regulations, policies or plans. These elements provide the foundation for developing the other three elements.

Following is a collection of countermeasures considered applicable to protecting transportation assets, as well as the functionality these countermeasures provide in terms of deterrence, detection, and defense. The terms defined below are consistent with Army Field Manual 3-19.30 – Physical Security. The implementation of certain countermeasures such as the surveillance systems has to be incorporated into the operation of Intelligent Transportation Systems (ITS) in the DOTs.

• Deterrence – A potential aggressor who perceives a risk of being caught may be deterred from attacking an asset. The effectiveness of deterrence varies with the aggressor’s sophistication, the asset’s attractiveness, and the aggressor’s objective.
• Detection – Detection senses an act of aggression, assesses the validity of the detection, and communicates the appropriate information to a response force. A detection system must provide all three of these capabilities to be effective.
• Defense – Defensive measures protect an asset from aggression by delaying or preventing an aggressor’s movement toward the asset or by shielding the asset from weapons and explosives. Defensive measures: (1) delay aggressors from gaining access by using tools in a forced entry, (2) prevent an aggressor’s movement toward an asset, and (3) protect the asset from the effects of tools, weapons, and explosives.

Next the countermeasures are mapped to the high-priority critical assets from Step 3

The effectiveness of countermeasures is measured subjectively by assessing how well its application reduces either the potential for or consequences of attacks on assets given specific threats and vulnerabilities.