Redundancy in Urban Public Infrastructure

Telstra public payphones are a familiar sight on Canberra streets. They offer free standard calls to Australian landlines and mobile phones. With mobile phones now widely used, payphones are no longer an everyday means of communication for most people. Yet Australia retains a substantial network and continues to invest in upgrading it.

In an EFTM interview on 12 May 2026, Telstra's payphones lead said the company had just under 14,000 payphones. Around 8,000 had been migrated to 4G backhaul or, in remote areas without 4G coverage, Starlink satellite backhaul. Telstra's 2025 Annual Report also disclosed that it had invested about A$7.5 million over the preceding few years to upgrade more than 1,000 payphones in disaster-prone areas, providing Wi-Fi and extended battery reserves.

These arrangements address reliability in both power supply and connectivity. A traditional corded telephone on a copper fixed-line network, requiring no separate mains power, can draw power from the telephone exchange. During a local blackout it may continue working, provided the exchange and connecting lines remain operational. That capability cannot simply be assumed for every public payphone today: it depends on the equipment, connection and backup power available.

Satellite communications can bypass some terrestrial infrastructure. A payphone using satellite backhaul may therefore retain a connection when a disaster disrupts the local ground network. Backup power can also reduce the impact of a local electricity outage. A 4G connection still depends on mobile base stations, so its disaster resilience depends on different conditions. Migration to 4G or satellite backhaul does not mean that every payphone retains several alternative connections at once. Each technology needs to be assessed for what it actually provides, but backup power and the use of different communications technologies show how public communications infrastructure takes failures and emergencies into account.

## Coverage in Canberra's bus network

Canberra's bus system offers another example. Its residential neighbourhoods are spread over a large area at relatively low density, and many households own private cars. If routes were determined entirely by passenger numbers, some lower-density neighbourhoods might receive inadequate services. Canberra's transport planning, however, has included explicit requirements for residential coverage.

Past ACT estate development rules used a coverage target of at least 90% of dwellings, with distance standards of 500 metres for local bus services and 800 metres for rapid services. These standards were also referred to in ACT Legislative Assembly proceedings in 2020. They do not mean that every home must be within 500 metres of a bus stop, nor should they be treated as a current mandatory rule applying to every dwelling. They nevertheless show the importance given to residential coverage in planning the network.

A walkability study commissioned by the ACT Government in 2013 found that the median walking distance from residential properties to a bus stop was about 260 metres. The result appears in the government's active travel planning document. It is a historical finding and should not be presented as a current measurement for the whole city.

Bus routes extend into different suburbs and residential neighbourhoods, travelling through a large number of streets. Borrowing a term from computing, this can be understood as a kind of “traversal” of the transport network serving the main residential areas. The analogy concerns reaching different neighbourhoods; it does not mean buses must travel along every road. This arrangement means that services still need to operate to their scheduled routes and timetables even where passenger numbers are relatively low.

Maintaining broad network coverage requires substantial public funding. In the ACT Government's 2024–25 Budget, Transport Canberra Operations had a budgeted annual total cost of about A$308 million and service payments of about A$221 million. The total cost included approximately A$41.06 million in depreciation and amortisation, while the organisation's activities also covered light rail, school buses and special needs transport. These figures therefore cannot all be attributed to suburban bus coverage, and service payments are not the same as an operating loss. They do, however, indicate the extent of public transport's reliance on government funding.

In Assembly proceedings in April 2024, the ACT Government explicitly described the need to balance patronage growth with adequate coverage in areas of lower demand. This approach takes account of the basic transport needs of residents without cars, older people, people unable to drive and others with limited travel options. Even where patronage on a particular route is insufficient to cover its operating costs, the government may retain it to maintain access to public services.

## Two different design principles

Payphones and buses are different kinds of public infrastructure, but both involve allocating resources beyond what everyday utilisation alone would justify. Backup power improves the emergency reliability of payphones, while satellite backhaul at some sites reduces dependence on local terrestrial communications infrastructure. These arrangements primarily address the risk of disruption caused by blackouts, damaged communications lines and other abnormal conditions.

Maintaining routes and stops in lower-density residential areas can, in a broader sense, be understood as redundancy in public service coverage. Its purpose is to ensure that areas and groups generating less demand can still access a basic public service. This differs from engineering redundancy that uses spare components or duplicated paths to cope with failures. It primarily addresses differences in where people live, their ability to travel and their demand for services.

Neither approach means that more infrastructure is always better, or that every lightly used service should be retained. Investment still needs to be assessed against construction costs, operating expenses, actual demand and available alternatives. Alongside efficiency under normal conditions, the allocation of public infrastructure needs to take account of reliability during disruptions and people's ability to access basic public services.