Conclusions and Recommendations
Ensuring the security of the U.S. air travel system and of American and foreign air carriers traveling to and from the United States is a monumental task. Currently, in the United States, this involves screening over 1.5 million passengers and their carry-on baggage every day for the presence of metallic weapons or dangerous materials. The FAA is investigating and considering the implementation of new technologies that improve the effectiveness of current screening procedures by tailoring them to address and comply with current security requirements. At the same time, the FAA is looking into technologies that address anticipated changes in security requirements by expanding on the ability to detect the presence of dangerous materials on a person. After reviewing and assessing these efforts, the Panel on Passenger Screening reached the following conclusions.
ASSESSMENT OF SYSTEM ENHANCEMENTS
People relate the level of inconvenience and the invasion of privacy they are willing to tolerate to their perception of the severity of the threat being averted and the effectiveness of the screening efforts at averting that threat. For example, air carriers and passengers accept more intensive security procedures for international flights because they perceive a higher likelihood of terrorists targeting international flights. Passengers would probably resent intense screening measures for domestic U.S. travel unless they had proof that the severity of the threat was higher than usual. If the threat is high, more invasive technologies that may inconvenience passengers are likely to be more acceptable than when the threat is perceived to be low.
Because of the strong relationship between public acceptance of security-screening processes and the perception of risk, the panel believes the FAA should make this link explicit in a strategy for implementing new passenger screening technologies. Because it is impossible to predict the course that terrorists will take in the coming years, the FAA plan should include specific technologies that can be implemented in response to specific threats. The FAA should also examine how new technologies will be implemented over time in the absence of specific threats against U.S. air carriers or airports.
By openly addressing the link between the perceived level of threat and public acceptance of more intrusive security-screening processes, the FAA will help air carriers react more effectively to specific threats. Air carriers will also be able to plan the purchase of equipment based on new technologies as part of their regular efforts to upgrade security-screening equipment.
Although the panel can formulate some general conclusions and recommendations about new technologies for passenger screening, further efforts to assess public acceptance and to incorporate the resulting information into screening procedures will be needed to ensure the effective performance of individual technologies. Besides considering various public acceptance reactions to new screening technologies, the FAA will also have to determine an acceptable level of opposition. As discussed in chapter 1, a certain proportion of the public will oppose the implementation of any new technology. Therefore, the FAA will have to weigh the need for more effective airport security systems against the known opposition before mandating implementation of a new technology.
Assessing public acceptance of new screening systems and procedures is a relatively complex and difficult task. The degree to which people will accept the inconvenience, discomfort, delays, embarrassment, real or perceived health risks, and real or perceived invasion of privacy associated with passenger screening depends on the interaction of several variables. The most important variable is the perceived level of threat. The reactions of passengers, air carriers, and airport operators to any new screening technology will be strongly influenced by the perceived level of threat, and efforts to assess those reactions must take this effect into account.
Courts have generally interpreted current screening processes and technologies as a reasonable search under the administrative search exception to the Fourth Amendment, even though the search reveals personal information, in addition to the presence or absence of dangerous materials. New technologies probably will be considered in the same light, taking into account the degree of intrusiveness of the search procedure, the magnitude or frequency of the threat, and the sufficiency of alternatives. The courts will also consider the effectiveness of the search in reducing the threat and will determine whether sufficient care has been taken to limit the scope of the search as much as possible, without compromising effectiveness. Concerns will be
raised about the legality of security screening or searches conducted without particularized probable cause, and new screening technologies are not likely to allay concerns about government surveillance of innocent people boarding an airplane.
The panel makes the following specific recommendations for using new technologies to improve passenger screening:
Recommendation: Indicate how new passenger screening technologies are integrated into long-range implementation plans for upgrading airport security.
Recommendation: Use a variety of means to assess public reaction to new passenger screening technologies:
· Identify important public acceptance issues by identifying similar or analogous circumstances from the past and by studying available information on public reaction to, and acceptance of, these circumstances.
· Assess public perception as early as possible in the development cycle.
· Assess public reactions to prototype systems.
· From earlier assessments, develop and maintain educational programs to inform the public about the advantages and perceived disadvantages of screening technologies.
Recommendation: Emphasize the importance of providing operators with information about the specific type and location of a threat item:
· Convenience. Screeners can more quickly determine whether or not the item that caused alarm is a threat, and passengers will experience less delay.
· Privacy. By allowing the screener to search only the area known to contain a suspect item, the screener is less likely to encounter external medical devices or other nonthreat objects that passengers consider personal.
· Legality. Limiting the search area will minimize the amount of information about nonthreat items passengers carry in their pockets and lessen the need for a policy on the discovery of illegal but nonthreat items. Current airport passenger screening techniques are open to charges that screeners may go beyond the limited right to search for threat objects. Technologies that allow only the identification of items considered a threat to the safety of the airport and the aircraft will eliminate this subtle element of doubt in the airport screening process. Air carriers and contract security companies must also ensure that their equipment is not designed or modified to detect materials that are not considered threat items.
IMPROVEMENTS TO CURRENT SCREENING SYSTEMS
Improvements to current metal-detector portal technology are expected to be transparent to passengers and the security-screening personnel. However, these improvements may increase screening efficiency by decreasing the number of false alarms and by allowing the screening personnel to resolve these alarms more quickly by providing information about the specific type and location of the object that triggered the alarm. Although no epidemiological studies have been conducted to evaluate the health effects of portal metal detectors and other passenger screening devices, data from epidemiological studies involving comparable radiation and field exposures from other sources suggest that there are no measurable health risks from these devices.
Although these technologies are mature and ubiquitous, the panel believes that improvements can be made to make them more effective for aviation security. The panel urges the FAA to continue to study technical ways to improve the metal-detection portals. Examples of areas where improvements can enhance the overall performance of current metal-detection portals are: (1) parallel algorithms for the simultaneous detection of different metals, alloys, and structures, and (2) detector arrays to localize contraband items within the portal.
TECHNOLOGIES TO MEET FUTURE PASSENGER SCREENING REQUIREMENTS
Technologies being developed can be broadly characterized as imaging technologies or trace-detection technologies.
It is not necessary that imaging technologies produce true-to-life images of the person being screened. Images produced using a variety of methods, both passive and active, can be effectively interpreted by well trained screeners with sufficient experience. In the current state of technology development, operators are required to interpret the images because humans are familiar with the human form and its many variations. Several public acceptance issues regarding the display of true-to-life images are likely to make these technologies difficult to deploy as primary screening technologies in airports. The panel recommends some strategies to encourage the traveling public to accept the use of imaging technologies in their current state of development:
· Make sure the images are viewed by a person the same sex as the passenger.
· The displayed images should not be visible to anyone but screening personnel.
· Offer alternative screening procedures for people who object to imaging.
· Mask portions of the displayed image.
· Guarantee that the images will not be preserved beyond the brief screening procedure, except when questionable objects are detected.
The first three strategies will require large investments from air carriers and airports. These increases in costs have led the panel to conclude that these imaging technologies, as they exist today, are not suitable as primary screening procedures, that is, screening procedures to which every passenger must be subjected. There may be a place in the system for these technologies, as second or third screening alternatives; for example, after a passenger has been identified as posing a high risk, either through passenger profiling or through another screening technology. Specific recommendations to enhance the feasibility of implementing imaging technologies are as follows:
Recommendation: Determine how much distortion can be introduced into a human image before screeners lose the ability to detect threat objects.
Recommendation: Develop image-analysis routines to remove the screener from the primary inspection process.
Recommendation: Determine the time required for passenger screening under realistic airport screening conditions.
Recommendation: Develop an appropriate public education campaign on the levels of radiation exposure from imaging technologies, including specific information on comparative levels of radiation, and address specific concerns, such as the effects of radiation doses on pregnant women and on medical devices.
Recommendation: Quantify the threat level at which these imaging technologies would be acceptable for general screening.
Trace-detection technologies rely on the collection of samples of explosive materials to identify the presence of a threat material. Collection can entail sampling the air around a person or touching a person to remove particles of explosive materials from their person, clothing, or belongings.
Technologies that require touching a person to collect a sample raise the concern that people may not want to be touched, either by inanimate objects such as fronds or by people wielding hand-wand devices. This concern is difficult to address because the desire to maintain distance from strangers is a deeply ingrained response that is often influenced by basic cultural and religious beliefs. The optimum distance people maintain between themselves and other people varies greatly from person to person and from culture to culture and is not likely to be swayed by public information campaigns. Privacy concerns about initiating physical contact may prove to be a significant hurdle to implementation. Noncontact methods of sample collection, such as using an air shower or a vacuum, are likely to be more acceptable to passengers, but they are also likely to be less effective than contact sampling. Screening personnel may already feel intimidated by the people they are required to screen. Technologies that require even closer interaction between them and the passengers are likely to exacerbate this problem. A specific recommendation regarding new trace-detection technologies is:
Recommendation: For contact methods of sample collection, emphasize techniques that collect secondary samples from something a person has touched or techniques that involve collecting samples from a less personal area of the body, such as the hands.
Nonimaging Electromagnetic Technologies
The dielectric portal technology uses microwave energy to interrogate a passenger to detect the presence of metallic or nonmetallic objects. Like active imaging technologies, dielectric portal technology is likely to raise concerns about the use of radiation. However, if this technology can be made specific to threat objects, then it may improve the detection of nonmetallic objects without raising concerns about image projection and without requiring that an operator interpret the image.
After investigating new technologies for screening passengers in airports, the panel determined that the systems presently used nationwide could be more effective by integrating the human operator more fully into the security system. The inability to maintain a high level of operator performance is a principal weakness of existing passenger screening systems and a potential weakness of future systems. Improving operator performance is as critical as technical improvements for enhancing current systems and ensuring the success of new passenger screening systems. Improving current technologies and developing new technologies both require balancing technological development and human operators in the overall security system.
Specific recommendations for improving operator performance in security-screening systems follow:
Recommendation: Develop techniques to measure operator performance for operators of current screening systems.
Recommendation: Study operator ergonomics, selection, training, and motivation for operators of current screening systems.
Recommendation: Determine the optimal balance between the automated system and the human operator in new systems.