Transport, Energy, and Equity: Rethinking How We Measure Accessibility

As Aotearoa New Zealand moves towards a lower-carbon transport future, much of the discussion focuses on cleaner vehicle technologies, alternative fuels, and electrification. Yet over the longer term, the scale and pattern of transport energy demand and consumption are also shaped by how cities and regions develop. This raises a broader question: how do land-use and transport systems shape the physical transport energy required for people with certain characteristics in certain locations to achieve accessibility?

That question sits at the centre of Ricky Doddy Sianturi’s PhD research at the University of Otago, with academic supervision from Dr Angela Curl and industry input and support from John Lieswyn and Glen Koorey at ViaStrada.

Titled “Bridging Land Use, Transport, Energy and Equity”, the research examines how urban form, the spatial distribution of opportunities, multimodal transport networks, and people’s individual and temporal constraints shape transport energy requirements. It then considers how those requirements vary across locations and population groups, with accessibility as the central outcome and equity as the lens for evaluating their distribution.

LOOKING BEYOND VEHICLE EFFICIENCY AND EMISSIONS
The transition to electric vehicles can substantially improve vehicle energy efficiency, reduce energy consumption, and reduce operational emissions. These technological improvements are important, but they do not necessarily change how far people need to travel, where everyday opportunities are located, or which transport options are realistically available to them. More accessible urban form may reduce the amount of travel required in the first place.

Ricky’s research therefore looks beyond vehicle efficiency and emissions by asking a different question: how much physical transport energy is required to achieve accessibility? In other words, how much physical transport energy is required for people with different needs and capabilities to reach essential and valued opportunities under different land-use and transport conditions?

Accessibility remains the central outcome, while transport energy is treated as a direct physical resource required to achieve it. This distinction allows technological improvements, such as vehicle electrification, to be evaluated alongside changes in land use, public transport, walking, and cycling on a comparable basis. The research aims to examine how land-use and transport planning can reduce transport energy requirements while maintaining or improving accessibility and people’s wellbeing.

UNDERSTANDING THE DISTRIBUTION OF TRANSPORT ENERGY REQUIREMENTS
Not everyone faces the same transport conditions. People living further from everyday opportunities, or in areas with fewer feasible transport options, may require more physical transport energy to achieve a comparable level of accessibility.

These requirements can also vary between population groups because factors such as age, disability, caring responsibilities, vehicle availability, public transport access, and other individual or temporal constraints can affect which transport options are realistically available.

Ricky’s research examines how transport energy requirements are distributed across locations and population groups, and whether systematic differences in those requirements raise equity concerns. Rather than assuming that every difference is inherently inequitable, the research uses equity as the lens for evaluating who faces higher resource requirements to achieve access, where those patterns occur, and what they may imply for land-use and transport planning.

GREATER CHRISTCHURCH AS A CASE STUDY
The research uses Greater Christchurch as its primary case study, a region characterised by substantial population growth, urban expansion, and changing land-use and transport patterns. It examines how different land-use and transport configurations shape accessibility, transport energy requirements, and their distribution across Christchurch, Selwyn, and Waimakariri.

Using spatial analysis, multimodal transport-network modelling, accessibility analysis, and demographic data, the research explores a range of future scenarios, including changes that bring activities and opportunities closer to where people live, improve public transport provision, expand feasible walking and cycling options, and increase transport energy efficiency through technological change.

SUPPORTING BETTER PLANNING DECISIONS
A key outcome of the research will be the development of accessibility metrics, models, and decision-support tools that can help planners and decision-makers evaluate the impacts of different transport and land-use interventions before they are implemented. 

By bringing together accessibility, transport energy, and equity, the research seeks to provide a more complete picture of how land-use and transport systems shape energy requirements and enable people to reach opportunities, how those requirements are distributed across places and communities, and how future policy can support both climate objectives and community wellbeing. 

For ViaStrada, the project reflects an ongoing commitment to evidence-based research that helps create more sustainable, efficient, and equitable transport systems for New Zealand communities.