Bridging the Security Gap

Protecting the nation’s iconic bridges


It is crucial that engineers resist the temptation to implement the highest technology solutions where they are not appropriate based on perceived need vs. real need. Whenever the net effectiveness of expanded detection zones around a bridge asset are suspect or costs associated with the specific application are prohibitive, then other technology and physical measures should be considered. For example, in areas where one technology may not be suitable, do not forget about other technologies that might work together to accomplish the same goal.

Combining different traditional detection technologies with video analytics through programming or a software management platform can help overcome the limitations that any one of these technologies might have on their own. Remember that some important benefits security technology can offer include pre-incident intelligence gathering and after-incident mitigation. Alerts associated with repeated suspicious activities by the same person or vehicle can focus law enforcement on prevention. Advanced information analysis of post-event activities can help direct authorities to suspects sooner and potentially prevent future attacks.

How terrorists may attempt to attack an iconic bridge cannot be predicted with certainty; therefore, it is appropriate to rely on layers of security technology rather than on any single device.

Theme 2 — Validate, Validate, Validate: Wireless video systems are all the rage and offer great appeal where the cost and impact of wired infrastructure are significant — like that of a historical bridge structure. Network IP megapixel cameras can provide excellent video, but bandwidth limitations may cap the number of cameras, their resolution, refresh rate or a variation of all these functions. How much bandwidth needed for effective video can vary even between models of the same manufacturer.

Video analytics is becoming a more mature technology and can do fancy things under controlled conditions. Many manufacturers are moving analytics functions toward the camera edge, relieving the network of the associated usage. Specialty video cameras offer the ability to monitor through any weather condition with megapixel clarity and deliver broadcast-quality detail.

The best way to address these design issues is to repeatedly field test these systems in the deployed environment. Major metropolitan iconic bridges offer some of the most challenging and varying field conditions faced by designers. These structures function as living entities in perpetual motion subject to the best and worst Mother Nature has to offer, depending on the time of year. Careful planning, repeated proof testing during the design of these systems and thorough systems commissioning during implementation are critical to validate that the systems and devices will perform as expected.

Theme 3 — Responsibility to Stakeholders (the whole must be greater then the sum of its parts): Advanced technology deployment is a significant responsibility that affects a great number of stakeholders indefinitely. How many of us hear a car alarm in a parking lot and do not pay any attention to it? We have grown so accustomed to these frequent technology failures that most of us don’t even bother to look. Studies of security system operators have shown that response to repeated nuisance alarms will compound and deteriorate significantly over time and increase the likelihood that these systems will be intentionally disabled or patently ignored.

Individual technologies like advanced presence detection, high-end specialty cameras and video analytics all offer excellent potential benefits to the security program; however, the primary importance of any security technology deployment still centers on the fact that responders must be presented with valid actionable information at all times. Every high-technology system has an anticipated percentage of “false” (invalid alarms) or “nuisance” alarms (undesired valid alarms). Multiple systems and hundreds of individual devices deployed in challenging environments amplify the undesired event likelihood significantly.

The greater the capabilities possessed by the high-tech solutions, the greater the possibility these technologies (either individually or in concert) will generate unwanted alarms. Increasing integration between systems (alarm triggers video and audio for example) amplify the unwanted results even further.