By Matt Burdett, 16 May 2018
On this page, we look at urban system growth including infrastructure improvements over time, such as transport, sanitation, water, waste disposal and telecommunications.
- Milano Centrale railway station, Milan, Italy. Urban infrastructure such as railway stations needs periodic upgrading, such as this US$120 million upgrade of Milan’s artistically important railway terminus. Source: By the author.
What is infrastructure?
In the study of geography, infrastructure usually refers to the built environment. This includes buildings and transport, as well as electricity, gas, water and sanitation connections.
Infrastructure is a very wide ranging term. One example of a wide definition is: “The basic structure, the framework, the system which supports the operation of an organization (e.g. the power and water supplies, the transport and communication facilities, the drainage system), which makes economic development possible, the basic capital investment of a country or enterprise” (Clark, 2004).
Hard versus soft infrastructure
There are two main types of infrastructure within an urban area. The first is that described in the definition above: the built environment, meaning the physical connections between places that carry people, materials, information and energy. These ‘fixed’ things include roads, railways, pipes, and cables. They are frequently called hard infrastructure or fixed infrastructure (Gotbaum, 2011).
In a wider sense, an urban area also has a social and economic infrastructure. This refers to the institutions that need to exist for the city to be maintained. For example, we can describe the ‘healthcare infrastructure’ as not only the hospital buildings but also the expertise of medical staff, money to pay for it, the legal system which allows it to happen and the political will to make adequate decisions about healthcare provision. This is known as soft infrastructure and is really about the ability to provide specialised services.
Essential elements of urban infrastructure
Essential infrastructure includes the following:
- Water supplies
- Waste disposal
These infrastructure are almost always run on a network system in urban areas. This means they have inputs, outputs, nodal points and links.
- Inputs: the material or energy coming into the urban system
- Outputs: the waste material leaving the urban system
- Links: pipes, roads and so on that distribute the energy or material through the system
- Nodal points: central locations which connect to each other; there are often many nodal points operating in a hierarchy, and nodes can be connected to more than one part of the system
The diagram below shows the links and nodes for a computer network, but the concept of network development applies to many different areas in geography too including physical infrastructure in urban areas.
- A simplified diagram of links and nodes. Source: Farkas and Raleigh, 2013.
Networks like this have several advantages. They minimise the risk of failure of the entire network by making it possible to isolate individual sections:
- Parts can be turned off and on, allowing for maintenance to happen without interrupting the entire system
- If one part fails, it can be ‘backed up’ by another part of the system that is still working
- Improvements can be made to one part of the system at a time
- Wholescale improvements can be done more efficiently by upgrading central nodes, and these improvements can ‘cascade’ through the system. A good example is the adaptation of telephone lines to high speed internet, as the nodes in the network can be upgraded to process more data, so the link itself doesn’t need to be altered. Another example is a congested road system, where changing the ways that junctions prioritise traffic can avoid having to build a new road.
- Waste outputs can potentially be recycled back into the system more effectively
In High Income Countries, governments and private companies frequently make improvements to networks to ensure sustainability. Yet “in most poor countries such infrastructure is grossly inadequate” (Collier and Venables, 2016) which causes major problems for people living in those cities.
Key concepts in urban infrastructure
There are several ways to look at urban infrastructure beyond simply describing it. Detailed descriptions of different types of urban infrastructure and the importance they hold within the city system are lower down this page, but first we discuss the key issues that planners have to consider when deciding what infrastructure is needed in an urban area.
Capacity refers to the amount of inputs, flows and outputs that a system can cope with. To be ‘below capacity’ is usually described as having unused parts of the network, or parts that are not used to their full extent, and therefore capacity is reached when all parts of the network are being used to their full extent.
Urban areas that have capacity in their networks are capable of meeting the needs of the population. If the capacity is reached or exceeded, the urban area struggles to meet the needs of people and will suffer social, economic and possibly environmental problems. For example, if the public transport system reaches capacity, there will not be enough space on the buses and trains to transport all the people who need to move around as part of their daily lives, which will cost businesses money in lost revenue, and prevent people from accessing the services they need.
A major concern for modern urban development is to make the infrastructure of a city as sustainable as possible. Sustainability in this context means that the infrastructure will be capable of supporting the environmental, social and economic needs of the city both today and in the future, assuming that it is maintained properly.
Sustainable issues include:
- Sustainable transport infrastructure, such as mass transit systems (subways / metros / underground systems)
- Appropriate energy sources
- Safe and secure housing e.g. that can withstand hazards such as fire and earthquakes
- ‘Future proofing’, such as by ensuring that infrastructure can be easily adapted to unknown future needs. This includes having a system capacity beyond what is currently needed. For example, if there is a new road being planned, it should be capable of carrying more cars than is currently needed so that as the city grows, it doesn’t need to be rebuilt.
In any city, some infrastructure is essential while some is optional. For example, a bridge across a river might be essential while a large sports stadium is not. Examples of essential infrastructure are power stations and electricity supplies, sewage systems, clean drinking water systems, major transport systems (metro systems and railways) and telecommunications networks.
Public sector infrastructure projects
Often, the national government takes responsibility for major infrastructure projects that are considered so important that they must not be allowed to fail, or are so large that no private company could take the project on. These projects generally have a direct impact on everyone in the city, not just the people who choose to use it. For example, a major ring-road (also called a beltway, perifico, orbital or radial road) will not only help the commuters who use it, but also reduce congestion in the city for everyone else by redirecting traffic away from gridlocked areas.
Private sector infrastructure projects
The private sector, i.e. profit making businesses, is generally responsible for non-essential infrastructure. Examples include building office blocks and housing, and profitable infrastructure such as mobile phone networks. For example, the switch from 4G to 5G mobile networks in the United States is predicted to cost US$104 billion, and will mostly be paid for by private cellular companies (Goovaerts, 2015).
However, the private sector is sometimes involved in major ‘public’ projects too. There are two main reasons why governments may still step in and either pay the private company for the project, or take control itself. Firstly, if the private company goes out of business, the government will be forced to step in. In 2018, the company Carillion went out of business. It was the UK’s second largest construction firm with 20,000 workers and even more contractors who relied on it for their income (BBC News, 2018). It was building projects such as the Midland Metropolitan Hospital, the Aberdeen Bypass and the HS2 which is a high speed rail line between London and the middle of the country (BBC News, 2018a). The UK government had to pay to continue these projects which were too important to not be continued.
Secondly, rural areas are even more expensive to connect (because of the larger land to cover, and the lower population to sell network access to) so the government will often subsidise a part of the cost. Since the 1980s there has been a gradual move towards using private companies to build more essential infrastructure too, but in almost every case the government is paying a large share of the bill.
BBC News, 2018. Carillion collapse: What next? http://www.bbc.com/news/business-42680590 Accessed 16 May 2018.
BBC News, 2018a. Mapping Carillion’s biggest construction projects. http://www.bbc.com/news/business-42717735 Accessed 16 May 2018.
Clark, 2004. The Penguin Dictionary of Geography (3rd edition). Penguin. London.
Collier and Venables, 2016. Urban infrastructure for development. https://urbanisation.econ.ox.ac.uk/materials/papers/110/oxf-rev-econ-policy-2016-collier-391-409.pdf Accessed 16 May 2018.
Farkes and Rayleigh, 2013. Designing Documents for Selective Reading, in Information Design Journal 20(1), January 2013. https://www.researchgate.net/publication/263192546_Designing_Documents_for_Selective_Reading?_sg=uIWvXLae0aSNSi8cxS-d76PM_LgTcuKKFFRvRJnR27MUbvTFH3FT5My0j1ERxQ8AsFgNHChJwkU7GVnXfl0EGKGS2vR5haQTFA Accessed 16 May 2018.
Goovaerts, 2015. iGR Study Forecasts $104B Cost to Upgrade LTE Networks, Build Out 5G Network. https://www.wirelessweek.com/news/2015/12/igr-study-forecasts-104b-cost-upgrade-lte-networks-build-out-5g-network Accessed 16 May 2018.
Gotbaum, 2011. The Difference Between Soft And Hard Infrastructure, And Why It Matters. https://stateimpact.npr.org/new-hampshire/2011/10/26/infrustructure-soft-and-hard/ Accessed 16 May 2018.
KPMG, 2012. Cities Infrastructure: a report on sustainability. https://home.kpmg.com/content/dam/kpmg/pdf/2012/05/Cities-Infrastructure-a-report-on-sustainability.pdf Accessed 16 May 2018.
Li, 2016. Infrastructure and Urbanization in the People’s Republic of China. https://www.adb.org/sites/default/files/publication/221431/adbi-wp632.pdf Accessed 16 May 2018.
TheONEbrief, n.d. Urban Infrastructure: Keeping Economies and People Healthy. http://theonebrief.com/urban-infrastructure-keeping-economies-and-people-healthy/ Accessed 16 May 2018.
Urban infrastructure: Learning activities
- Define ‘infrastructure’. 
- Distinguish between hard and soft infrastructure. 
- What is ‘essential infrastructure’? 
- What is a ‘nodal point’? 
- Explain why many urban infrastructure on a network system. 
- For an urban area you know well, can you identify any ‘critical points’ in the infrastructure that, if they fail or need updating, affect the entire urban area? Outline the possible impacts and explain their severity. (If you are struggling, consider the road system: is there anywhere that suffers traffic congestion? If not, explain how the urban infrastructure in this area is networked to prevent this from happening.) 
- Define ‘capacity’ in relation to urban infrastructure. 
- Suggest and explain three problems that an urban area may face if three different infrastructure networks exceed capacity. 
- What is meant by ‘sustainability’ in the context of urban infrastructure? 
- Explain how and why governments are often directly involved with large infrastructure projects. 
In a small group, design an urban area. You can decide whether to build a new area or improve an existing one. This is not a real simulation of urban planning, but an opportunity for ‘blue sky thinking’ which means to think without any constraints. What infrastructure would your design include? When you have finished, annotate your design to explain the choices you made, and check that you have included all the different types of infrastructure discussed on this page (e.g. did you remember to include cellular phone networks?). If there are several groups working simultaneously, hold a discussion and have a vote about which is the best city and why. One consideration you may think about is: what are the socio-economic and demographic characteristics of this city’s population, and does it meet their needs? Another is: does your city resemble any of the urban models such as Burgess’s Concentric Zone Model, and why?