and environments for safe, comfortable, and effective human use” (Chapanis, 1991, p. 1) so that we may “optimize the relationship between technology and the human” (Kantowitz and Sorkin, 1983; Licht et al., 1989, p. 27). The application of Complex Adaptive Systems of Systems engineering as discussed in Chapter 2 would necessarily consider the relationships between humans and underground infrastructure.
The military has long recognized the importance of integrating human and technological system elements to make operations as effective, efficient, safe, and sustainable as possible, and has promulgated these concepts through directives and guidance. For example, a Department of Defense (DOD) directive from 1988 required consideration of manpower, personnel, training, and safety in the defense system acquisition process for the purpose of improving “all aspects of the human-machine interface” (DOD, 1988: p. 1).2 In 2007, the National Research Council published a report at the request of the Army Research Laboratory, the Air Force Research Laboratory, and DOD to address approaches for creating “an integrated, multidisciplinary, generalizable, human-system design methodology” (NRC, 2007, p. 2). That report outlines principles considered critical to human-system development and evolution including those associated with the need for stakeholder consensus on desired outcomes, regular reassessment of plans based on lessons learned, and risk management.
Many applications of human factors engineering are related to human interaction with a single manufactured item or technology. Underground systems as part of total urban environments are more complex, and the need to understand, design, regulate, and operate for human-technology relationships becomes amplified. The impact of failure of key infrastructural components—including human—and or systems can be devastating to sustainable functioning of the urban environment (see discussion of cascading failures in Chapter 2). Human behavior is not always predictable in the face of adverse and extreme events, and regardless of how resilient to hazards underground infrastructure and safety systems may be, infrastructure and system failure could have significant negative consequences. All forms of underground engineering not only must consider what training and safety guidelines are necessary for the smooth functioning of infrastructure in the best of circumstances, but also must anticipate the behavior of underground occupants during both normal and worst-case operation scenarios. Design must be holistic and create an integrated environment that allows people to almost intuitively understand how to remain safe should adverse conditions arise. Sustainability of the urban setting is dependent on optimization of human-technical relationships in ways that provide at least minimum safety while remaining consistent with long-term societal visions.
Industry also addresses safety in underground infrastructure. The International Tunneling Association (ITA), for example, established the Committee on
2 This directive has since been replaced by other directives that also emphasize human factors.