The AIR Research Project

Developing multi-disciplinary evidence-based comprehension of the interfaces between metro infrastructure and its environment.


In this section find out about:

  • the AIR research project which will see the development of standardised processes of interface analysis of transport infrastructure and its environment;

  • the context for the research, and why the outputs are important to current and future urban management; and

  • the aims and objectives of the research, to develop and apply cost and time saving processes, which will enable effective asset data management for transport organisations and their stakeholders, internationally. 


The densification of urban environments, globally (United Nations,
undated), requires effective processes for the analysis of the presence, property, and protection interfaces between transport infrastructure and its environment Darroch 2012; 2014; 2020; Darroch et al., 2016; 2018; 2020a; 2020b). Subsequent sharing of that data within transport infrastructure managing organisations and their interfacing urban stakeholders contributes to:

  • organisational cost and time savings;

  • effective implementation of sustainable asset and urban management processes; and

  • the development of effective sustainable transport and urban management policies and planning.

Collectively, these ensure the safe continued presence and operation of that transport infrastructure and its environment.

While the following pages discuss the reasoning for developing and implementing the AIR research project, based on my PhD research (2014-2019), it is hoped that it will be of interest to urban and transport practitioners, and those with an enthusiasm for the history of urban environments and their transport infrastructure, internationally. After all you are all urban stakeholders, in some way form or manner!

Urban underground metro infrastructure as an integral part of urban infrastructure

In 2018, “168 million passengers [used] metros in 182 cities within 56 countries every day”, it is anticipated that an “additional 1400km of metro line will be added every year from 2018-2022” (IUITP, 2018). Where those metro systems “are designed to serve travel corridors where demand is heavy and are particularly suitable for inner urban areas or linking high density population centres to city centres” (Institution of Civil Engineers, 1987, p.11). To achieve this, urban underground metro infrastructure (UUMI) forms an interconnected and interdependent component of the urban environment.


Fig.1: A busy day at Earls Court London Underground station. All of these passengers are urban stakeholders, with an interest in the safe presence and operation of the urban environment for work, leisure, shopping, residence, and travel. Source: REX, undated.


Darroch, 2020, p.51, defined UUMI as:

those physical and meta physical infrastructure designed, constructed, and maintained to enable the creation of a combination of subterranean, below ground, and minimal surface infrastructure to create urban underground space for the operation of and access to, high frequency, high capacity passenger trains.

UUMI consists of, but is not limited to: surface buildings, entrances to urban underground space, underground ticket halls, tunnels, shafts, passageways, and structures forming the space within which trains and passengers can pass and repass.

Whilst the term UUMI is used for these structures, the principles are the same for the creation of any surface or underground space within an urban environment, such as a utilities subway, highway tunnel, underground car park, or underground shopping mall”.


Fig.2: A simplified diagram showing the presence and property interfaces of urban underground metro infrastructure and its environment. The diagram is based on real occurrences of London Underground metro infrastructure and its environment where the sub-surface railway tunnels can be located 0.2-5m below ground level.


The interconnected and interdependent nature of UUMI within urban environments therefore creates presence, property, and protection interfaces, with other forms of urban infrastructure (Fig.2). These interfaces are affected and affect one another for the whole lifecycle of infrastructure presence (Darroch, 2012; 2014).

This results in the need to comprehend that where something is present, many and various urban stakeholders will have an interest in the safe continued presence and operation of that environment and its related infrastructure (Darroch et al., 2016; 2018; 2020a).

Darroch 2020, defined the terms:

  • interfaces as “’a situation, way, or place where’ metro infrastructure and its environment come together and affect each other. Thus, enabling effective, sustainable, management of those interfaces, during periods of urban change or urban management” (p.36); and

  • urban stakeholders as “all those present within, or with an interest in, the safe presence and operation of the urban environment. This includes, but is not limited to: infrastructure owners, maintainers, and users, such as a Metro organisation, local highway authority; land or building owners/lessees; business owners; shopper; commuters; tourists. If the urban environment is not effectively changed and managed, it may not function well thus having adverse impacts on the activities of those stakeholders, above” (p.50).

The occurrences of the presence, property, and protection interfaces are not just contemporary (now), but have been created over decades, and will continue to occur over future decades, for the whole lifecycle of metro and urban infrastructure presence (Figs.3 and 4). For example, the oldest UUMI, in the world (the Metropolitan line, in London, between Paddington and Farringdon), is rapidly approaching 160 years old and is still in daily use today (Figs.3 and 4).


Fig.3: Drawing showing the site of

Clerkenwell Road Bridge, London, UK, in 1868. Source: British History Online, 2017.


Fig.4: Photograph showing the site of

Clerkenwell Road Bridge in 2016. Source: Bing Maps, 2017.


The interconnected and interdependent presence of that UUMI within the urban environment of London as representative of other international urban environments), has created and been affected by multi-disciplinary factors. Examples of which include but are not limited to: legal (legislation, policies, regulations, and contracts, common law rights and responsibilities), civil engineering, urban and transport planning, asset management, geographical, and historical, indicated in Fig.2 (law and property).

The need for multi-disciplinary analysis and comprehension of the interfaces

To maintain the safe presence and operation of the urban environment and its interconnected and interdependent infrastructure, these multi-disciplinary considerations must be comprehended and incorporated within stakeholder organisational (metro, utilities, highway, railway, transport, and urban planning) urban change and urban management strategies and polices. The data generated and shared within urban infrastructure owning/maintaining organisations and with their interfacing stakeholders, can subsequently be employed in developing effective Building Information Modelling processes (BSI, 2020; ICE, 2020).

Where Darroch, 2020, described:

  • Urban change as “the act of altering temporarily or permanently urban infrastructure in a proposed, planned, designed, and agreed way between interfacing urban stakeholders. This should not adversely affect the safe presence and operation of those interfacing stakeholders, other urban infrastructure, or the use of the urban environment through the actions of the urban stakeholders undertaking urban change” (p.49); and

  • Urban management as “the act of maintaining and repairing urban infrastructure in a proposed, planned, designed, and agreed way between interfacing urban stakeholders. This should not adversely affect the safe presence and operation of those interfacing stakeholders, other urban infrastructure, or the use of the urban environment, through the actions of the urban stakeholders undertaking urban management” (p.50).


Fig.5: Diagram showing how evidence-based data, from analysis of the interfaces of transport infrastructure and its environment, should form part of organisational data sharing. Note the feed data in/feed data out nature of the wheel, to ensure effective data sharing within an organisation and with its stakeholders. The two workflows within the wheel form the core of the AIR research project. Source: Darroch et al., 2020b.


To assist the safe presence and operation of metro infrastructure, within its contextual environment, effective, accurate, evidence-based (Darroch, 2020) “data is essential to transportation asset management decision making", Li, 2019, p.19 (Fig.5). Where that asset management decision making is not just applicable to UMMI, but also to its contextual environment.

Holding information within one organisation, or one department within an organisation, is, however, not sufficient, nor efficient. This is because of the interconnected and interdependent nature of UUMI and urban infrastructure forming the urban environment, where they affect one another for their whole lifecycles.

Truly sustainable urban management can therefore only occur through effective sharing of evidence-based data and reasoning for the occurrences of interfaces between stakeholders. Where that sharing of data enables the development and maintenance of a common shared comprehension, of how, when, where and why, metro infrastructure interfaces with its contextual environment (RAIB, 2014; Darroch, 2020).

The AIR research project

The purpose of the AIR research project, is to develop and apply, within participating metro infrastructure owning/maintaining organisations, and in collaboration with their interfacing stakeholders, an internationally applicable standardised Asset Interface Register (AIR).

The register will be created through:

  • the application of a conceptual framework representing the interfaces of UUMI and its environment;

  • application to the conceptual framework of supporting processes for undertaking the multi-disciplinary analysis of existing and proposed occurrences of the interfaces;

  • gathering evidence-based data, providing reasoning for the occurrence of the interfaces;

  • development and application of processes for reaching collaborative agreement of the gathered evidence-based data; 

  • publication of the key findings from the analysis, using a GIS interface to increase evidence-based data within asset portfolios;

  • develop internal and external comprehension of asset interfaces;

  • provide standardised approaches to asset/interface analysis, documentation of key findings, and sharing of data, to enable effective asset and urban management;

  • enable enhanced multi-disciplinary application of Building Information Management and Cadastre (property register) development;

  • thus saving time and money on asset data management for existing and future infrastructure interfaces, within UUMI owning/maintaining organisations, and their interfacing stakeholders; and

  • ensuring the enhanced safe continued presence and operation of their interfacing infrastructure and its environment.

Do you want to find out how, when and why the AIR research project was developed?

Why not continue to the Context of the AIR research project page.

If not, why not have a look at the Examples of the interfaces page.



London, UK

©2018 by Nathan Darroch