Reimagining post-pandemic roads, at least for any permanent change, requires a 3D perspective that considers the disruptions coming from the world of buried infrastructure below our urban roads. Vehicles are not the only disruptions.
There’s been a plethora of articles regarding “reimagining our urban roads” for the post-pandemic. [1,2,3,4,5,6] Many of the articles show an image of a strangely vacant road to express a type of blank canvass for urban planners. The common theme being the possibilities for social engagement on our roads that enable peaceful protests, artistic expression, socially distanced cafés, and a pedestrian and bike thoroughfare for when our cities fully reopen. Yet, buried underneath this post-pandemic vision, in a corrosive soil matrix, are the sectors  of infrastructure that provide the literal foundation and critical basic services that sustain a city. Even though these sectors are intended to be out-of-sight-out-of-mind, there are daily reminders that, unless we simultaneously reimagine our urban distributive infrastructure , we will never have a blank canvas. We have become inured to the constant reminders of our buried infrastructure, e.g. the ubiquitous spray-painted urban hieroglyphics (i.e. utility locates) and road/lane closures to facilitate ongoing maintenance and repair, as shown on Figure 1.
The juxtaposed scenes in Figure 1 are so common that we do not question if we should have these disruptions – it is simply part of urban life. In fact, the streets of NYC are cut open 550 time a day to facilitate buried infrastructure repairs, replacements, and maintenance. And, despite the omnipresent utility markings (hieroglyphics) on the pavement, accidental damage to infrastructure costs NYC $300 million per year. These disruptions will prevent the reimagining of our urban roads (at least the implementation) and, until cities quantify the associated indirect costs, no one/entity/institution understands the “true cost” of urban infrastructure.
This blog is not intended to ruin a great post-pandemic vision of urban roads, but to enable it with a 3D urbanism perspective that provides for a collaborative workspace space for both engineers and urban planners. While it’s not fair to say that each discipline works in a 2D perspective, as terrain and elevations are important for both, it might be fair to say that, within the urban environment, the ground surface is a physical barrier between these two disciplines. Urban planners occupying the above ground world (AGW) and engineers the below ground world (BGW). The physical nexus of AGW and BGW is the planning/engineering of our urban transit. But for engineers the word “infrastructure” originated from a French engineering term meaning “beneath‐structure” used to describe the construction work below the roads. And, for urban planners, consider the reverence of Allan B. Jacobs’ book Great Streets (1995) that presents a series of 2D views of how streets are laid out in great cities. As an engineer, this blog will not dive into the possibilities of reimagining the social possibilities of the AGW, but rather offer a few suggestions to urban planners for utilizing the 3D perspective to better connect the two worlds.
As with many problems, the difference in perspective and language between the two worlds are barriers. While planners discuss and communicate plenty at their conferences, and engineers at theirs; the intra-siloed communication has not led to a methodology for assessing and quantifying how our decaying  buried urban infrastructure impacts urban planning. Consider a source of confusion for perspective. Engineers typically work within a single sector (e.g. water, sewer, communications, transportation). Yet, the signs of disruption to a city posed by the underlying decaying infrastructure are everywhere in a city. Figure 2 is a typical day in Toronto with over 600 road or lane closures (ranging “major” to “minor”). In addition, the City of Toronto filled in 12,000 potholes in just the month of April (2020). The engineer views each road or lane closure as part of a required process for maintaining that sector of infrastructure. The urban planner (resident, business owner, and everyone else in the city) views each of these hundreds of daily events as disruptions. For such a frequent event in a city, it is amazing that no city is quantifying the economic impact of decaying urban infrastructure.
Of course, there are many other causes of these disruptions, including; poor construction, climate change, capacity requirements, and new technologies. But the images in Figure 1 and the disruptions depicted in Figure 2 are cause and sector agnostic. They are simply indicators that the current paradigm of where we place our urban distributive infrastructure will not facilitate uninterrupted reimagined post-pandemic roads – at least if we don’t reimagine the infrastructure paradigm .
Connecting AGW and BGW with the Utilidor
It is actually up to the urban planners to connect the two worlds – beginning by defining spatial areas of a city that should not be disrupted by decaying infrastructure . The one key criterion that will end disruptions – regardless the cause – is accessibility. If our urban infrastructure can be easily accessed without cutting into urban roads, then a host of disruption causes would cease: including; proactive maintenance; elimination of poor installation and construction damage during repairs; and assets  could easily be replaced for new capacities and technologies. Utility tunnels (aka, utilidors) have been used for decades and are increasingly a major part of the urban infrastructure planning scheme in China, Australia, and much of Europe.  By placing utilidors that are designed for HS-20 live loading, cities could protect critical urban corridors from disruption.  The failure in the US is that we have not viewed utilidors from the urban planning perspective. Rather, we have viewed utilidors as a BGW engineering domain. But it is the disruptions, costs, and indicators that impact the AGW and urban planning.
 ‘sector’ refers to the individual infrastructure systems that delivers an essential service to the city, for example, transportation, energy, water, sewer, solid waste, stormwater, etc. through pipes, cables, vehicles, pavement. An ‘asset’ is a component of an infrastructure sector (e.g. gas main).
 See ‘We Can’t Solve Aging Infrastructure if We Can’t Talk About It’ for more details
 Reiner, M, and Cross, J. (2018). Addressing the Infrastructure Decay Rate in US Cities: the case for a Paradigm Shift in Information and Communication, in Gardoni, P. Routledge handbook of sustainable and resilient infrastructure. 1st ed. London and New York: Routledge, pp.791-807.
 See five-part series starting with ‘From Appian Way to Modern Decaying Infrastructure’
 See four-part series starting with ‘Communication Breakdown – City vs Asset Management’
* cover photo obtained from google search for "pedestrian streets"