What are the current trends regarding urban infrastructure planning that lend themselves to supporting a new urban infrastructure paradigm as a foundation for smart and resilient cities? And, what differentiates an assemblage of technologies as a new paradigm?
The RABID (Roads and Buried Infrastructure Decay, from Part 1) paradigm is generations old (in concept) and it is clear that cities “…have paid insufficient attention to maintaining and expanding their infrastructure assets, creating economic inefficiencies and allowing critical systems to erode.” [1] But there is momentum in infrastructure research and planning that promotes adaptability and consideration of collocation hazards [2, 3, 4]. The current theme of sustainable infrastructure planning is now to “…approach urban infrastructure as a series of systems that should function in synergy and be directly linked with urban planning.” [5]. Note, that a “series of systems” is a larger vision beyond single utility sector planning. This requires a key stakeholder that has a significant stake in promoting this larger vision as a foundation for a resilient and smart city, i.e. city leadership (e.g. city manager, mayor, and senior staff). But for city leadership to be effective as a utilities stakeholder, they should be empowered with city-centric key performance indicators (KPIs) that quantify the negative economic and social impacts that are experienced daily from decaying urban infrastructure.
In the KPMG report – Emerging Trends 2019 – an encouraging trend is that “…gone are the days where infrastructure could be planned in distinct silos…” [6]. While this is a welcomed trend, planning across utilities requires an incentive, or quantified reason to do so, and a vision of an alternative to the confines of the RABID paradigm. The KPMG trend could be better stated as – gone are the days of urban infrastructure inaccessibility as this would help reverse the trend of deferred maintenance and allow flexibility for new infrastructure and changing capacity requirements. Another KPMG predicted trend is that “… infrastructure authorities and planners will move towards a more holistic and evidence-based decision-making processes.” [6]. Again, while ‘evidence-based decision-making’ sounds reasonable, logic will not be victorious when the paradigm places too many restrictions on necessary decisions, and city leadership does not yet have an alternative vision to clearly communicate to the public [7].
Academic research is similarly moving towards changing the language regarding the rigidity of infrastructure planning. Consider the term “lock-in” that defines the constraints that cause rigidity in infrastructure planning and therefore, a call for more flexible approaches to avoid these constraints [3, 8]. Markolf [3] further elaborates on lock-in:
“Lock-in is perpetuated and often exacerbated by the related concept of path dependency, which refers to constraints on a system’s ability to change (e.g., adapt or transform), in that it is often very costly and difficult to alter an existing infrastructure system from its current trajectory.”
Again, referring to Donella Meadows (from Part 1) [9] - “Paradigms are the sources of systems.” The goal of avoiding ‘lock-in’ is not having to “…alter an existing infrastructure system…”, but to create a paradigm where the goals of each individual system are not constrained. This concept is similarly supported by Chester and Allenby’s term “adaptive flexibility” [10] that describes a paradigm where systems can be updated and replaced without disruption. This trend of designing infrastructure to be updated without disruption fits well with cities that have smart/resilient goals. This trend of demanding flexibility for urban infrastructure is also prevalent in smart city standards. For example, ISO 37152 claims new, smart infrastructure should “…maintain its efficiency in adaptive manners against any changes of city’s circumstances including disasters and demographic changes to improve financial and resource efficiency and convenience for people (resiliency / dependability)” [11].
However, despite the chronic urban disruptions from failed infrastructure replacement, repair, and maintenance; the abundance of research is focused on the acute threats from natural disasters. This results in designing new resilient infrastructure assets, or individual projects (e.g. a new water treatment plant), without addressing the much larger decaying system (e.g. hundreds/thousands of miles of decaying main), most of which is located within the inaccessible RABID paradigm. A new urban infrastructure paradigm requires a new environment that allows for adaptive flexibility, avoids lock-in, and counters the threats of natural disasters, capacity changes, and chronic decay.
Utility Tunnels and Introduction to Disruption Free Corridors
From an urban planning perspective, there are critical economic, traffic, residential, and industrial corridors in a city where disruption would have an immediate economic and social impact. As mentioned in Part 2, there are daily disruptions from road cuts to access infrastructure ranging from multiple per day (Arvada, Co) to hundreds per day (NYC). While only a few of these disruptions occur in critical corridors in a city, the geographic location and costs that the city must bear are not quantified [2]. As a starting point for building the foundation of smart and resilient city status, these critical corridors must be defined and a new infrastructure paradigm is required to end these disruptions.
The idea of placing infrastructure systems inside an accessible tunnel (trading the soil matrix of RABID, and associated horizontal separations - discussed further in Part 5, for an air matrix) below busy streets is not a new concept. The first accessible utility tunnels were installed in the 19th Century in London (1869) and Hamburg. In fact, utility tunnels are currently fairly prevalent in the developed nations. A typical example is shown in Figure 1.
Many universities, colleges, and large institutional campuses have a network of utility tunnels [12]. Utility tunnels can also be found in cold weather climates where excavating through permafrost, ice, or rock is impractical [13]. Utility tunnels, also known as ‘utilidors’ and Multi-Utility Tunnels (MUTs) [14], have long been praised as the solution for addressing routine maintenance, replacement, or upgrade of buried urban infrastructure [15].
“The requirement of easy maintenance is realized for all lines so that damage or malfunctions of individual systems also from outside can be recognized in good time and future high resulting costs can be saved. These costs concern not only those for repair of the damage but also especially for the inspection that in the past has often been neglected and now will have a much higher priority.”
But it is the motivations for the Walt Disney World “utilidor” that best matches a city’s interests and perception as a smart city – avoiding disruption to the economic engine. The Disney utilidor consists of 15-ft walkways for maintenance facilities and utilities, including a vacuum trash system for garbage [12] that has successfully led to a disruption free enterprise.
Globally, many European and Chinese cities are pursuing utility tunnels to address a broader view of why a city should consider investing in the associated higher upfront capital costs – safety, continuity of urban life, and reducing deferred maintenance [16]. Mao & Zhang [17] provided a more holistic city centric perspective of the modern utility tunnel as:
“…a public tunnel for centralized laying of municipal [utilities] which can effectively solve the problem of repeated excavation of pavement, overhead network and frequent accidents, promote urban… development, improve the urban synthetic carrying capacity and the quality of urbanization development, stimulate social capital investment, create a new impetus to economic development and so on.”
While utility tunnels have long been known and accepted for utility placement, they are not discussed as a paradigm to serve as a foundation for the smart/resilient city. For the city to adopt a new urban infrastructure paradigm, long-term economic justification is required, as is the need for adaptive flexibility to accommodate more utility assets; e.g. non-potable water networks, Pneumatic Waste Collection, Combined Heat and Power pipelines, and district heating/cooling, hydrogen [14].
Given the near full build-out of many cities, and the time required to change a paradigm, another approach may at least consider starting a redundant system by boring under the RABID paradigm without replacing it, immediately. For example, where geologically possible, could tunnels be bored below the city cost effectively to accommodate utilities and additional modes of transit? While addressing around 3,800 mayors and city officials from across the United States at the National League of Cities’ 2018 City Summit, Elon Musk stated that “The Boring Co. is also going to do tunneling for, like, water transport, sewage, electrical. This would allow cities to address utility issues without much hassle.” [18] Again, this series of blogs is technology agnostic and is emphasizing quantifying the inefficiencies of the existing RABID paradigm to justify a new paradigm. Simply moving utilities into a tunnel (precast or bored) does not create a new paradigm. A paradigm, being a framework containing basic assumptions, must be based on sound reasons for implementing change.
The previous and next parts to this blog include:
Footnotes
[1] Woetzel, J., N. Garemo, J. Mischke, M. Hjerpe, and R. Palter. 2016. Bridging Global Infrastructure Gaps. McKinsey Global Institute. June 2016, p.1
[2] Reiner, M., Fisher, S., Fang, A. Total Economic Disruption of Failed Infrastructure as an Urban Key Performance Indicator. Sustain. Resilient Infrastruct. 2019 Pending.
[3] Markolf, S.A., Chester, M.V., Eisenberg, D.A., Iwaniec, D.M., Davidson, C.I., Zimmerman, R., Miller, T.R., Ruddell, B.L., and Chang, H. (2018). Interdependent Infrastructure as Linked Social, Ecological, and Technological Systems (SETS) to Address Lock-In and Enhance Resilience. Earth’s Future, 6(12). https://doi.org/10.1029/2018EF000926
[4] Markolf, S.A., Hoehne, C., Fraser, A., Chester, M.V., and Underwood, B.S. (2019). Transportation resilience to climate change and extreme weather events – Beyond risk and robustness. Transport Policy, 74(2). https://doi.org/10.1016/j.tranpol.2018.11.003
[5] Pollalis, Spiro N. Planning Sustainable Cities: An infrastructure-based approach, 1st Edition
2018 Routledge, 20160520. VitalBook file.
[6] KPMG. (2019). Emerging Trends in Infrastructure 2019. Retrieved from https://home.kpmg/xx/en/home/insights/2019/01/emerging-trends-in-infrastructure.html
[7] Reiner, M, and Cross, J., Addressing the Infrastructure Decay Rate in US Cities: the case for a Paradigm Shift in Information and Communication, in Gardoni, P. (2018). Routledge handbook of sustainable and resilient infrastructure. 1st ed. London and New York: Routledge, pp.791-807.
[8] Corvellec, H., Campos, M. J. Z., & Zapata, P. (2013). Infrastructures, lock-in, and sustainable urban development: The case of waste incineration in the Göteborg Metropolitan Area. Journal of Cleaner Production, 50, 32–39. https://doi.org/10.1016/j.jclepro.2012.12.009
[9] Meadows, Thinking in Systems, a Primer, 2008 ISBN-13: 978-1603580557
[10] Chester, M. V., & Allenby, B. (2017). Towards Adaptive Infrastructure: Flexibility and Agility in a Non-Stationarity Age. Sustainable and Resilient Infrastructure. https://doi.org/10.1080/23789689.2017.1416846
[11] ISO/TR 37152 First edition 2016-08-01 Reference number ISO/TR 37152:2016(E) Smart community infrastructures — Common framework for development and operation
[12] Texas Transportation Institute; The Texas A&M University System. (2002). UTILITY CORRIDOR STRUCTURES AND OTHER UTILITY ACCOMMODATION ALTERNATIVES IN TXDOT RIGHT OF WAY. College Station, TX: Texas Transportation Institute. Retrieved from https://static.tti.tamu.edu/tti.tamu.edu/documents/4149-1.pdf
[13] Examples of cold weather utility tunnels are: Barrows, Alaska; Nome, Alaska; Fort McPherson, Alaska; Norman Wells in the Northwest Territory, Canada; University of Alaska at Fairbanks; and McMurdo field station, Antarctica
[14] Hunt, D., Nash, D., & Rogers, C. (2014). Sustainable utility placement via Multi-Utility Tunnels. Tunneling And Underground Space Technology, 39, 15-26. doi: 10.1016/j.tust.2012.02.001
[15] Abschnitt, Retrieved from: http://www.unitracc.com/know-how/fachbuecher/rehabilitation-and-maintenance-of-drains-and-sewers/rehabilitation/replacement-en/utility-tunnel-en
[16] Yang, C., & Peng, F. (2016). Discussion on the Development of Underground Utility Tunnels in China. Procedia Engineering, 165, 540-548. doi: 10.1016/j.proeng.2016.11.698
[17] Mao, Y., & Zhang, Y. (2017). Risk identification and allocation of the utility tunnel PPP project. AIP Conference Proceedings, 839(020132). doi: 10.1063/1.4982497
[18] Retrieved from: https://www.teslarati.com/the-boring-company-building-tunnels-sewer-lines-elon-musk/