A utilities subway, Paris, France
Utilities subways can play an essential role in urban environments. In many countries these are predominantly located under public highways, but not exclusively so. Even where they are located under the public highway, the ownership, rights, and responsibilities interfaces must be fully comprehended to enable effective urban management.
Utilities subways enable the locating of cables and pipes within a purpose-built environment, enabling effective inspection, maintenance, repair, and replacement of essential urban infrastructure without digging up the highway surface, which could adversely affect highway traffic flows (www.parliament.co.uk, 2011; Valdenebro and Gimena, 2018; Li, et al., 2019). Fig.1, shows an example of a utilities tunnel in Paris, France, located under a public highway.
Fig.1: Diagram showing the design of a multi-level utilities subway (utilidor), in Paris, France. Source: National Research Council, 2013.

As with any urban infrastructure, however, the presence of utilities tunnels within the urban environment creates interfaces with other urban infrastructure. However, this is arguably more beneficial than leaving utilities within the highway environment, within which there may be UUMI. For example, Fig.2, shows typical occurrences of the interfaces of utilities and UUMI within a highway, identified through the 2014-2019 research.
Fig.2, not only shows the presence of the utilities within the highway, it also presents potential asset ownership for the different utilities. E.g., water mains, sewers, telecoms, electricity cables, gas mains. All of which would be accommodated within the utility’s subway.
Fig.2: Diagram showing the potential interfaces of utilities within a public highway and their interfaces with UUMI.

Fig.3: Diagram showing the design of a multi-level utilities subway (utilidor), in Paris, France, with suggested property interfaces. Source: National Research Council, 2013.
