Literature Review

A literature review for research into spatial justice and smaller connected autonomous renewable energy vehicles (CAREV-S) in Sydney

1 Introduction

This literature review[1]is thematically arranged as follows:

1.      Orthodox discourse on vehicles in the city

2.      General research context in relation to AV/CAV/CAREV[2]spatiality

3.      Ergonomic and smaller vehicle typology research

4.      Spatial justice, vehicles and the city

5.      Urban heat island study – increasing active transport or environmental space through CAREV

1.1 Orthodox discourse on vehicles in the city

The orthodox debate about vehicles and the city feels interminable, varied, complex and heated. Central themes include banning vehicles, providing more public transport and active transport provisions to reduce road congestion and improve environmental conditions, and pedestrianisation, to name a few objections. Anti-vehicle[3] movements since the 1930s[4]have advocated for increased living densities in city centres, congestion taxing, and pedestrianisation or shared zones in which vehicles share space equally with active transport users[5] or exclude vehicles completely.

Counterarguments are similarly polemical, including advocacy for the provision of more new road infrastructure, increasing safety, productivity and decongestion. Advantages of new road infrastructure include tolling, decongestion, increased productivity and economic opportunities.[6] The principal economic arguments focus on the use of public funds for improved roads or improvements to public transport systems.[7] The arguments become politically and economically oriented due to the magnitude of the issues and the economics of construction and operations of motorways in urban areas.[8] Governments of various persuasions swing between policies and opportunities, exploiting local issues as is suited to the peculiarities of the location and community.

Some community action groups in Australia are strongly opposed to new motorway projects.[9]These stakeholder groups contribute important dissenting voices. For example, the Public Transport Users Association (Victoria, Australia) wrote an article on 22 February 2022[10] titled ‘Myth: Self-driving cars will cut congestion and make public transport obsolete’.[11] Pressure from local communities for low traffic neighbourhoods[12] suggests that in many cities the amount of car space will be reduced dramatically in coming years, although there are counterarguments to the low traffic environment movement.

Perverse outcomes are also the subject of much debate and discussion among transport journalists and urban planners. Articles such as Wired’s 2014 article by Adam Mann, ‘What's Up With That: Building Bigger Roads Actually Makes Traffic Worse’,[13] note the unreasonable outcome that results from building more infrastructure to resolve congestion. This spatial investigation discusses the perverse outcomes of smaller CAREVs, as there are potential advantages, disadvantages and paradoxes; however, the approach the research takes is that a novel technology and novel spatial investigation have the potential to shift the debate. Presenting new opportunities and discourse does not resolve the issues but perhaps provides opportunities to learn from and improve the current circumstances.

The NSW Government (and both major political parties) generally resists social objections in this field.[14] Major objections tend to be brought to parliament for inquiry through smaller objecting parties. One of the strongest positions in the Environmental Impact Statement (EIS) process utilises a ‘do nothing’ option in infrastructure supply as a contending argument. The ‘do nothing’ option retains the status quo, which is that traffic conditions will worsen..EISs generally avoid publishing forecasts of increased population, consumption patterns and related traffic increases in their assessments, which would distort the planning outcomes. The EIS process has, until recently, also avoided climate change assessments; through court actions, these assessments are now limited to the climate change assessment of a particular project, which avoids the broader assessment process.

Two decades ago, Guy Baeten[15] in The Tragedy of the Highway: Empowerment, Disempowerment and the Politics of Sustainability Discourses and Practices’ commented on similar issues[16] in relation to a Flemish study of a highway in Ipres and Furnes. In this article, he notes the critical reflection regarding the pacifying words ‘sustainable transport’. He argues that the phrase ‘sustainable transport’ is part of the orthodox ‘vision’ that leads to the established empowerment of technocratic principles and elitist groups in society. The pacification aids the delegitimisation of minority social groups, including environmental groups. Not much has changed in this part of the debate. Sustainability is increasingly used in greenwashing discourse. However, the climate crisis has worsened and made the debate poignant.

I agree with many of Baeten’s assertions; however, I argue that CAREV-S and the intelligent city could shift thinking through design by introducing new variables. The disruption of technology and spatial opportunities offer an opportunity to reimagine the debate if developed systemically and through careful, thoughtful design. The research and design spatial investigation of smaller CAREVs (CAREV-S) and the future intelligent city introduces three new variables into the debate, as discussed in the spatial study.

CAVs, according to several studies, such as the OECD report[17]andWadud et al.,[18] identify energy efficiency benefits that range from 15% to 40%, depending on various parameters, with modelling studies based on fossil-fuelled CAVs. There are industry coalitions, such as Partners for Automated Vehicle Education PAVE (2016)[19] and the Australia & New Zealand Driverless Vehicle Initiative (ADVI)[20]amongst others citing multiple benefits for CAV/AVs.To clarify, the spatial investigation assumption is that the study isrelated to renewable energy that is CAREVs[21] manufactured and operating in a circular economy. That is, the manufacturing operates using green power, and the material supply utilises low or negligible extraction principles.

1.2 General research context AV/CAV spatial justice

In this research, spatial justice is both a product and a decision-making process. The contested public realm, and especially road space, references John Rawls, ‘A Theory of Justice’ (1971),[22] regarding the redistribution of geographies. The decision-making justice provision referencesIris Marion Young’s ‘Justice and the Politics of Difference’, in her book on transportation policy and how to set targets and goals that redistribute space justly.[23]The public realm is a highly contested space, and the rights to the space are of interest to all sectors of society. This spatial-investigation focuses on increasing the active transport area and the environmental area of the contested space in the road corridor, thus improving the environmental aspects of the city and the policies that could realise multiple benefits, an approach that is seen throughout the public realm community of urban designers, planners and landscape architects.

The European Union (EU) is a leading authority on road transport systems internationally, partially due to the high use and manufacturing base of vehicles in Europe and the long history of urbanisation. The EU stands in contrast, notably on questions of social justice, to the American and Asian authorities in their approach to road transport systems.[24] According to the report by Raposo et al. published for the European Union (2018),[25] it appears through various CAV studies that this technology promises to contribute to fewer negative impacts from road transport while also generating new mobility paradigms and transport governance opportunities. The EU report sets out environmental outcomes (cleaner systems, decarbonisation) and equitable/sharing (social justice-related issues), making the comments, ‘It is expected that EU transport activity will continue to grow in the coming decades, with road transport maintaining its dominant role’.[26]

Roposo et al. continue[27]

‘Vehicle automation will act as a transformational technology in the freight transport sector by diminishing operating costs and allowing more efficient logistics. These benefits would justify the idea that this sector becomes one of the early adopters of CAV technologies. The two most costly elements in commercial vehicle operation are fuel and drivers, both of which can be reduced through truck automation.’

The report also states that ‘inequality between low-skilled and high-skilled workers will widen as a result of CAV, this is due to the increases in the technological advancement of the system’[28]Furthermore, economic effects across industries are tabulated[29], various authors make assumptions about the magnitude of the CAV industry in Europe, ranging from US$ 51billion to $1.2 trillion annually, highlighting uncertainty in the field.[30]The report indicates that there is likely to be a significant change in the economy and markets because of CAV. One such disruption is Mobility-as-a-Service[31] (MaaS).[32]

The key concept behind MaaS is to offer travellers mobility solutions based on their travel needs, essentially a vehicle-sharing system. Specialist urban mobility applications are also expanding their offerings to enable MaaS, such as Transit, Uber and Lyft.[33]There is extensive research being undertaken, including that of the Royal College of Art (RCA) in MaaS.[34]It is worth noting that MaaS systems in Sydney had an extraordinarily modest uptake in 2016[35] and that private vehicle ownership remains a dominant force in road vehicle economics. One of the most contentious of all issues in the orthodox debate about vehicles and the city is related to the amount of space private vehicles occupy in comparison to buses. This introduces the contentious issue of space.

Vehicle ownership is a core capitalist and commercial agenda; hence, the importance of addressing its fundamental complexity and conflicts is a core undertaking in my research. MaaS is essentially attractive from a distributive justice point of view; however, it is unlikely to address the issue that individuals in democratic capitalist cultures believe they have ‘rights’ to move around privately. Private vehicle ownership, as complex as it is and as difficult as it is for increasing populations in cities, is likely to remain in some form in the future CAV context. Consumerism and planned obsolescence have a major role in the industry, a subject discussed in detail at the conclusion of the PhD.

Potts et al.’s[36] research ‘Relationship of Lane Width to Safety for Urban and Suburban Arterials’ (2007) ‘investigates the relationship between lane width and safety for roadway segments and intersection approaches on the urban and suburban arterial’, the report also states ‘The research found no general indication that the use of lanes narrower than 3.6 m (12 ft) on urban and suburban arterials increases crash frequencies. This finding suggests that geometric design policies should provide substantial flexibility for use of lane widths narrower than 3.6 m (12 ft). Narrower lanes should be used cautiously in these three specific situations unless local experience indicates otherwise.’[37] The report is associated with human-driven vehicles, which require additional lane width for vehicle ‘driver drift’. According to Lily Elefteriadou, An Introduction to Traffic Flow Theory (2014)‘lane width is a design outcome based on physics, comfort and acceptable safety risks (driver drift) perceived by the community and culturally based attitudes’.[38] CAV and AV vehicles utilise machine intelligence driving and consequently require less vehicle drift space in normative operations. However, CAV metrics are not currently available as the technology is still in trial.

Despite major publications on traffic, such as Peter D. Norton’s‘Fighting Traffic: The Dawn of the Motor Age in the American City’(2011)[39], there is a lack of data on the implications of the size of vehicles in blocking roads[40]. It appears to be accepted engineering and cultural practice that vehicle sizes are rarely called into question. The question that this research asks is are existing vehicles larger than they need to be and why are they getting bigger? Norton,[41]an authority on traffic in the USA, notes ‘traffic engineers’ studies resort to wider roads and flow increases, ITS and other congestion-relieving strategies’.[42] Congestion begins with chokepoints in terms of network performance. Chokepoints are demand areas that are far greater than throughput capacity at any point of a road network. As a result, congestion grows through the network until the chokepoints are removed by reducing demand or increasing capacities in current congestion models.[43]

That vehicles appear to be increasing in size is a subject not frequently discussed.[44] Form Trends,[45] a motor vehicle publication, in one of the few articles available on the subject, notes that historically, smaller vehicles have been less desirable as ‘conspicuous value’, this suggests that society does not value smaller vehicles as much as larger ones! IIHS-HLDI crash testing and highway safety in recent research note the perverse safety outcomes of Sport Utility Vehicles (SUVs)[46], and recent research confirms that SUVs have increased lethal outcomes for pedestrians. Safety advocates, authorities and manufacturers are complicit in not attending to larger high-speed (sport) vehicles such as SUVs worsening pedestrian road fatalities. The consumer of the vehicle is the hegemonic decision maker in consumption and use.

As status symbols, car dimensions, especially in car manufacturing centres such as the USA, have rarely accepted the sensible and necessary smaller vehicles seen in European vehicle manufacturing, with examples such as the Citroen 2CV[47], the Mercedes A1 Smartcar, the UK’s Mini, the Italian Fiat 500 and the Renault Twizy not replicated in American vehicle typologies. Segway and General Motors in 2007 developed the Personal Urban Mobility and Accessibility (PUMA)[48] prototype in New York, a rickshaw-like electric vehicle. MIT held a vehicle seminar and competition in 2006 on personal mobility vehicles.[49]Mausbach[50](2010:178) notes that vehicle two-seater configuration has not had mass adoption, despite the rationality of the proposal.

1.3     Ergonomics and smaller vehicle typology research

Design publications recommending a fleet of smaller vehicles include those of Mitchell[51] and Burns[52], the benefits of which include lower energy use, less embodied energy, improved spatial, parking and environmental benefits and better safety outcomes. Neither of these major studies investigate capacity and spatial benefits in the road space of the city, a research gap that this study fills.

Large vehicle trends include Moving Spaces[53] research. This is also summarised in Plumer et. al. ‘Cars take up way too much space in cities’.[54] These studies include ‘robotaxi’[55](companies such as Uber, Waymo, WeRide, etc), focusing on larger vehicle typologies. There is an attempt to ‘fit more’ into a vehicle, or in speculative design processes, such as those discussed in Forbes by Nargess in an article on Pix[56] modalities, a modular vehicle type. ‘Moving Space’ and current vehicle trends in broad terms investigate larger vehicle formats. Larger vehicle formats are supported by articles by local engineers such as Stephen Taylor, who in a 2021 opinion piece, ‘Time for NSW to get a scoot on e-scooters’, writes, ‘Australians want bigger electric vehicles’.[57]A counter argument is that there is also research into CAVdelivery and freight vehicles, such as that which Aarian Marshall discusses in Wired[58]; however, these are generally not passenger transporting vehicles.

A leading design publication, recommending a fleet of smaller vehicles, is William J. Mitchell et al.’s 2010 book ‘Reinventing the Automobile: Personal Urban Mobility for the 21st Century’.[59] Mitchell, a leading scholar at MIT,[60] presents the benefits of smaller vehicles, but this important research does not investigate the traffic effects on the city. He argues that the smaller vehicle typology requires less embodied energy for manufacturing purposes (embodied energy) and less operational energy to move the vehicles and occupants, thereby reducing overall energy consumption

Mitchell also explores the positive impacts of parking smaller vehicles as spatial benefits. Notably, he does not explore the social justice implications. Importantly, in the publication and supported by other authors such as Burns,[61] visions of smaller vehicles for personal mobility are discussed. Small vehicles provide a redistributed equity of spatial use within the broader public realm. This is a key spatial concept that may partly explain the broad popularity and use of vehicles, alongside comfort, convenience, privacy and cultural practice.[62]Large cars are popular with a wide demographic, including lower-income cohorts, some of whom are dependent on them for access to places of work and recreation and are essentially elitist. This is also true where there is limited public transport or because of location and raises the issue of inequalities. This subject is discussed by Matt Wade in an opinion piece on ‘How our cities work: essential lessons from lockdown’.[63]

Australian census 2017[64], reveals that about 68% of daily private vehicle trips are undertaken by the vehicle driver only. 5% of trips to work include a driver and one passenger.[65]Comparative studies into traffic management through smaller vehicle types or reduced seating configurations are not available, which is a research gap.

1.4     Spatial justice and vehicles in the city

Spatial justice in transportation is an important component of understanding how the public realm is used. Karel Martens has has written authoritatively on transport justice in ‘Transport Justice: Designing Fair Transportation Systems’.[66] He writes, ‘the definition of a fair transportation system as a system that provides a sufficient level of accessibility to all under most circumstances may not seem radical in character, its consequences for transportation planning could not be more radical.’ Following the leading luminary Iris Young’sanalysis in ‘Justice and the Politics of Difference’,[67] it could be argued that transportation planning based on principles of spatial justice that ignores the powerful processes of domination and oppression that systematically disadvantage groups in society, such as ethnic minorities, women, and LGBTQA+ persons, is inherently socially unjust.

Kara Kockelman, a USA authority, argues with her team in their 2017 study, ‘An Assessment of Autonomous Vehicles: Traffic Impacts and Infrastructure Needs’,[68] that CAV under certain conditions would result in major decongestion effects on various road systems with time and demand-based modelling, which included spatial effects. This is an assertion that many CAV authors in this field share[69]. Kockelman’s study undertakes simulated modelling, taking assertions further into a deeper appreciation of impacts. For this reason, it appears to be a unique and significant study.

One study assumption in Kockelman et al., (2017) in an otherwise rigorous model, was that the autonomous vehicle sizes and configurations would remain consistent with existing human-driven vehicle sizes. A critical review of the modelling would immediately question why this assumption was made. It is evident from the ergonomics of a CAV that no driver would be required, and, therefore, the internal layout and ergonomic formation of CAV vehicles should change to assist with CAV congestion modelling. This omission is a central spatial question for my research.[70]

Minority groups[71] interested in autonomous vehicle mobility options will be especially interested in spatial justice issues with respect to equitable access and just movement. Haning, Gazby and Woolmer note in their report, ‘Forum report on persons living with disabilities’, that the disabled persons’[72] cohort preference[73] for road-based transport was associated with improved privacy and accessibility.[74] Furthermore, due to socio-economic constraints,[75] these groups tend to be associated with lower-income urban settings[76] and live on the periphery of major cities. The AV industry has made strong representations to the aged and people living with disability groups regarding the potentialities of the technology to respond to the private and public transport needs of these minority groups.[77] The economic aspects and the cost of travel in the CAV/AV system are, according to Kogelmann (2017)[78], affordable at scale. CAREV will assist with mobility options for people living with disabilities and the aged.[79]This has been identified by the National Highway Traffic Safety Administration (USA) in their policy statement on AV.[80]

Botello et al.[81] (2019), in their research and consultation across a wide interdisciplinary spectrum American on ‘Planning for walking and cycling in an autonomous-vehicle futures’ notes:

‘Several respondents suggested that cities should set strategic priorities for transportation and land use. These priorities should be formulated independently of technology—and focus on the communities' vision is for the future. CA/Vs and other technological innovations should then be integrated in this overall strategic vision. For example, a city could decide to prioritize liveability and active travel. Such a city would then allow deployment of C/AVs as long as they further that goal. In essence, the suggestion is to not allow technology to set the strategic agenda, but to employ technology to achieve strategic goals’.

The principle of society determining the vision, and the technology designed to suit the principle is discussed in the findings of this research. Notwithstanding this insightful article’s assertions, it does not question the size of vehicles or their impacts on the contested public realm spatiality.

Hua Sha’s doctoral thesis, ‘Investigating the System-level Performance of Connected and Autonomous Vehicles Against Transport and Broader Societal Impacts’, evaluates and quantifies the potential impacts and benefits of CVs, AVs and CAVs based on the various traffic conditions in urban and suburban environments.[82]He demonstrates that standard-size CAVs ‘improve the efficiency of the road network, reduce emissions and conflicts’, suggesting ‘that policymakers will need to make some tough decisions in future as to how these new technologies will be implemented’. This technical study assumes standard vehicle sizes and has a cause–effect approach to environmental outcomes and does not set environmental targets or principles. The deep investigation does not pursue smaller vehicle spatial outcomes to benefit the environment. It does not take a systemic environmental approach to vehicles and the city, accepting standard vehicle sizes a priori.

1.5     Urban Heat Island effects of a CAREV-S system

One aspect of CAREV-S and evolving urban research that will become increasingly important in urban climate change studies is understanding how to reduce urban heat island effects. Arnfield[83] notes in his ‘Two Decades of Urban Climate Research that ‘a characteristic feature of work during the period of this review is the emergence of the idea that there are many UHIs, displaying different characteristics and controlled by different assemblages of energy exchange processes.’ Arnfield notes the characteristics of modelling street temperatures on nocturnal and daytime situations are not exact and to some extent depend on the software and hardware input.

In relation to this research output, the development of a UHI study is an important component of understanding the broader and specific detailed environmental and spatial implications of CAREV-S. As this UHI study is a simplified data output and modelling sample, it should be regarded as an initial step in understanding the implications of CAREV-S on the urban form.

One way to measure the cumulative effect of vehicles and the city is through UHI studies.[84] The environmental impacts of CAREV (and CAREV-S) using an urban heat island study are not available. There is no data contained in the RCA’s contribution to the GATEway[85] publication on the subject. GATEway identifies additional trees in the streetscape as an aesthetic outcome, which is an obvious conclusion and one I support. Hua Sha’s doctoral thesis did not use UHI to measure the environmental effects. The UHI impacts of additional space being reassigned from road space to environmental space as a result of CAREV-S are also not published. This is a research gap. For this UHI research, I utilised the Universal Thermal Climate Index (UTCI) as a baseline measurement system.[86]

Multiple landscape design practices and UK and Australian governments documents[87] and policies have identified that the additional planting of trees in the public realm can reduce urban heat island impacts and provide environmental benefits. The link between vehicle typology and urban environmental outcomes is not established in these articles, but it is an obvious link to me.

UHI data for CAREV-S were not available, and it was not possible to argue for the transformation of the urban environment through CAREV-S without the necessary data. I undertook a limited UHI module of research to provide modelled urban heat island data for CAREV-S as a specific speculative vehicle typology. The research finding is that CAREV-S has multiple environmental benefits, including UHI reductions. The study is located in a typical densely populated urban context in Sydney. Modelling showed UHI reductions of 3–4°C. The UHI study related to CAREV-S is part of a provocative discussion to clarify transdisciplinary thinking about CAREV-S. It shifts the dominant academic debate from a focus on shared-use vehicles to an environmental response to private-use vehicles. The implications of the private use of AV in the city as an environmental approach are part of this contribution.

The research argues that in the change of fleet from human-driven to autonomous vehicles, there is a need and opportunity for a more spatially just outcome in the use of the public realm through vehicle redesign. Increasing active transport networks[88] and individual mobility options (e.g. electric bikes and e-scooters) creates a more flexible system that is resilient. Increasing the flexibility of the vehicle typology system by focusing on individual transport requirements to reduce environmental impacts requires a systemic approach that is substantially different from the current operational systems.

Taking the widely accepted urban approach to increase active transport modality, a change in the fleet to narrower, smaller vehicles should also reduce the current hard surfaces and increase environmental space by rebalancing or redistributing the current standard vehicle lane width. The benefits of manufacturing smaller vehicles multiply the environmental benefits. Such an approach requires a systemic environmental framework to set the principles for all the stakeholders in the transport and urban sector to respond appropriately and systemically. The approach includes the community.

[1] This literature review highlights researchers and their findings from leading publications. It discusses current debates and thinking in the field, relevant spatial justice policy frameworks and current research trends in the industry, academia and society.

[2]Definitions of Autonomous Vehicles (AV), Connected Autonomous Vehicles (CAV) and Connected Autonomous Renewable Energy Vehicles (CAREV) are provided.

[3]For example, CosminPopan. ‘Car-Free Initiatives from Around the World: Concepts for Moving to Future Sustainable Mobility.’ Accessed February 8, 2022.

[4] Jane Jacobs, The Death and Life of Great American Cities. Reissue edition. (New York: Vintage, 1992).

[5]This book provides information on a variety of approaches on anti-car movements in the USA. Peter D. Norton, Fighting Traffic: The Dawn of the Motor Age in the American City. (Cambridge, Massachusetts: MIT Press, 2011).

[6]This is a recent example of the typical newspaper debate on road tolling systems: Dwyer, Adrian. ‘The Journey towards a Fairer Road Toll System.’Sydney Morning Herald, November 25, 2021, Roads edition. https://www.smh.com.au/national/the-journey-towards-a-fairer-road-toll-system-20211124-p59bso.html.

[7] GiulioMattioli, Cameron Roberts, Julia K. Steinberger, and Andrew Brown. ‘The Political Economy of Car Dependence: A Systems of Provision Approach’,Energy Research & Social Science, 66 (August 2020) https://doi.org/10.1016/j.erss.2020.101486.

[8] Australia, and Australia, Department of Transport and Regional Services.Bureau of Transport and Regional Economics, David Cosgrove, David Gargett, Estimating Urban Traffic and Congestion Cost Trends for Australian Cities. Canberra, ACT: Bureau of Transport and Regional Economics, 2007.

[9]Our Transport, https://ourtransport.org.au/community-action-groups/[March 21, 2022].

[10] Public Transport Users Association, Victoria, Australia, ‘Myth: Self-driving cars will cut congestion and make public transport obsolete’,https://www.ptua.org.au/myths/robotcar/[February 22, 2022].

[11] Summarising PTUA Victoria’s position: ‘It’s almost certainly untrue that robot cars will have any positive effect on urban traffic congestion. Nor will they exert any magical effect on urban travel that obviates the need to develop public transport networks as a congestion-free and environmentally friendly alternative for moving large numbers of people.’

[12] Low traffic neighbourhoods are evidenced in debates in the UK and to a lesser extent in Australia. The vast distances and low scale cities seen in Australia have their own specific transportation needs. There are also counter movement to the low traffic neighbourhood that form part of the orthodox debate. See also https://en.wikipedia.org/wiki/Low_Traffic_Neighbourhood/

[13]Adam Mann, ‘What’s Up With That: Building Bigger Roads Actually Makes Traffic Worse’, Wired, June 17, 2014,https://www.wired.com/2014/06/wuwt-traffic-induced-demand/

[14]Patrick Sisson, ‘Would You Pay Money to Make Traffic Worse? The U.S. Has Been Doing That for Decades’, Curbed, March 6, 2020. https://archive.curbed.com/2020/3/6/21166655/highway-traffic-congestion-induced-demand

[15]GuyBaeten, ‘The Tragedy of the Highway: Empowerment, Disempowerment and the Politics of Sustainability Discourses and Practices’, European Planning Studies, 8, no. 1, (February 2000), 69–86. https://doi.org/10.1080/096543100110938. [accessed 19 January 2023]

[16]Baetern (2000: 70) ‘There are, so to speak, as many definitions of “sustainability” as there are authors publishing on the topic (see, for instance, Franks, 1996; Basiago, 1995; Naess, 1995). Moreover, in spite of the vast sustainability literature, the main academic disciplines which contribute to the theorization of “sustainable transport” actually fall back upon pre-existing conceptual frameworks which, in general, do not require transport analyses to be revisited. Neo-classical economists, spatial planners and ecologists alike struggle to insert updated versions of their respective established doctrines into the hegemonic sustainability discourse in the hope that, by putting their doctrines high on the sustainability agenda, they will finally gain wide acceptance in the transport field under the politically and scientifically safe umbrella of “sustainability”. Neo-classical economists (see, for example, Proost& De Borger, 1997) insist on the sustainable character of implementing “correct” pricing policies which truly reflect demand and supply in a free transport market, unhindered by State interference. Spatial planners (for instance, Breheny, 1992) stress the necessity of “compact” spatial development so as to reduce transport demand and to facilitate supply. Ecologists (see, for instance, Royal Commission on Environmental Pollution, 1994) maintain that current motorized traffic volumes have to be brought down in order not to exceed “environmental thresholds”’.

[17] International Transport Forum, Urban Mobility System Upgrade: How shared self-driving cars could change city traffic, OECD Corporate Partnership Board, 2015 <https://doi.org/10.1787/5jlwvzdk29g5-en> OECD (2015:28) [accessed 19 January 2023]. Philippe Crist and Sharon Masterson, coordinators of the related OECD autonomous vehicle publication, provide modelling for two traffic data sets and a summary acknowledging policy choices will change outcomes. The value of this research is that it provides data on modelling (of TaxiBot/AutoVot fleets) with clear assumptions and scenario-based inputs for the models. The models are essentially crude; the data is useful to leverage further analysis and development in spatial terms. They state (2015:5), ‘In all cases examined, self-driving fleets completely remove the need for on-street parking’, while the model ignores social needs and desires, which may include the convenience of parking outside of residences.For example, it makes the point AV will result in spatial changes to the city.

[18]ZiaWadud, Don MacKenzie and Paul Leiby,‘Help or Hindrance? The Travel, Energy and Carbon Impacts of Highly Automated Vehicles’, Transportation Research Part A: Policy and Practice, 86 (April 2016), 1–18. https://doi.org/10.1016/j.tra.2015.12.001. They state (2016:1) ‘We explore the net effects of automation on emissions through several illustrative scenarios, finding that automation might plausibly reduce road transport GHG emissions and energy use by nearly half – or nearly double them – depending on which effects come to dominate.’

[19]Partners for Automated Vehicle Education (PAVE),(2016)https://pavecampaign.org/[accessed 19 January 2023]

[20] Australasian Driverless Vehicle Institute,https://advi.org.au/[accessed 19 January 2023]

[21] CAREV energy supply is the subject of a separate chapter of the PhD. Suffice to say renewable energy sources reduce (preferably eliminate) pollution associated with fossil fuels that effect the entire ecological chain, air, water, soil and biota.

[22]John Rawls, A Theory of Justice (Harvard University Press, 1971), https://doi.org/10.2307/j.ctvjf9z6v

[23]Iris Marion Young, Justice and the Politics of Difference(Princeton, N.J: Princeton University Press, 1990)

[24]European Commission, The Future Development of the Common Transport Policy: A Global Approach to the Construction of Community Framework for Sustainable Mobility (European Commission, 1993) https://op.europa.eu/en/publication-detail/-/publication/67d2cd43-9740-42b0-8ba8-e759d36f3109 [accessed 18 October 2021] (1993: 15) ‘Settlements have very diverse demographic structures, requiring mobility systems that can be adapted to become more inclusive and accessible to everyone.’

[25]Maria Alonso Raposo and others, An analysis of possible socio-economic effects of a Cooperative, Connected and Automated Mobility (CCAM) in Europe - Effects of automated driving on the economy, employment and skills.(Publications Office of the European Union, Luxembourg, 2018:150).http://dx.doi.org/10.2760/777

[26]Ibid. (2018:42).

[27]Ibid (2018:107).

[28] Ibid (2018:146).

[29] Ibid 2018:34–35) tabulation of economic industries.

[30]Ibid. (2018:38).

[31]Miloš NMladenović, ‘Mobility as a Service’, in International Encyclopedia of Transportation, ed. by Roger Vickerman (Oxford: Elsevier, 2021), pp. 12–18 https://doi.org/10.1016/B978-0-08-102671-7.10607-4 AV users are expected to receive an information book and pay for a choice of different mobility services by accessing a ‘one-stop-shop’ or ‘mobility platform’ via digital interfaces. Although highly uncertain, Mobility as a Service (MaaS) has significant potential to exert a considerable impact on the socio-technical domains in and beyond mobility.

[32]GöranSmith, ‘Making Mobility-as-a-Service: Towards Governance Principles and Pathways’ (Chalmers University of Technology, 2020) https://research.chalmers.se/en/publication/516812 [accessed 18 August 2021]

[33]Wikipedia, Mobility as a Service, https://en.wikipedia.org/w/index.php?title=Mobility_as_a_service&oldid=1073409292[February 22, 2022].

[34] The RCA IMDC Mobility Metamorphosis symposium comprised three themes for the day-long symposium; one-third of the day was assigned to MaaS and related share mobility. MaaS is a significant research field throughout the world, and specifically in the AV CAV field.

[35]In 2016 Deloitte estimated that Uber ride share comprised 6% of the overall taxi market in Sydney. Deloitte, ‘Economic Effects of Ridesharing in Australia’ (Deloitte, 2016) <https://www2.deloitte.com/content/dam/Deloitte/au/Documents/Economics/deloitte-au-economics-economic-effects-of-ridesharing-australia-150216.pdf> [accessed 20 January 2022]

[36]Ingrid BPotts, , Douglas W Harwood, and Karen R Richard, ‘Relationship of Lane Width to Safety for Urban and Suburban Arterials’, (2007:27)

[37]Ibid (2007: i).

[38]LilyElefteriadou, An Introduction to Traffic Flow Theory, (New York, NY: Springer, 2014),61–91. https://doi.org/10.1007/978-1-4614-8435-6_3.

[39] Peter D Norton, Fighting Traffic: The Dawn of the Motor Age in the American City (Cambridge, Massachusetts: MIT Press, 2011)

[40]To be clear, I could find no research on this matter. To suggest that smaller vehicles will intuitively reduce or alter congestion is not to my knowledge a field with any established research.

[41]Peter D Norton, Fighting Traffic: The Dawn of the Motor Age in the American City (Cambridge, Massachusetts: MIT Press, 2011:x)

[42]Anecdotally, I asked local engineers in the traffic and infrastructure space if they knew of studies on congestion that included smaller vehicles. The typical response is that vehicles are getting bigger not smaller and that there are no published studies on smaller vehicle impacts on congestion. This review of literature supports this lack of knowledge.

[43]Braess Paradox is a reminder that new roads can increase congestion and closing existing roads can decrease congestion. Changing the fleet to a smaller vehicle might bring about a new paradox of its own worsening congestion conditions. Wikipedia, Braess’sParadox, Wikipedia, 2022 <https://en.wikipedia.org/w/index.php?title=Braess%27s_paradox&oldid=1075509227> [accessed 21 March 2022]

[44] Recent unpublished RCA IMDC vehicle taxonomy research suggests that personal mobility vehicles are perhaps less significant from a research point of view than shared vehicle types. Universally, smaller vehicle publications focus on parking benefits and ease of movement but do not have specific congestion-related research supporting them.

[45]Form Trends,Less Is More – The Biggest Drivers for Smaller, Simpler Cars, (September 1, 2020)https://www.formtrends.com/less-is-more-biggest-drivers-for-smaller-simpler-cars/[Accessed 20 January 2023]

[46] IIHS-HLDI, New Study Suggests Today’s SUVs Are More Lethal to Pedestrians than Cars (June 16, 2020) https://www.iihs.org/news/detail/new-study-suggests-todays-suvs-are-more-lethal-to-pedestrians-than-cars[Accessed 20 January 2023]

[47] Wikipedia,Citroën 2CV,(March 6, 2022). https://en.wikipedia.org/w/index.php?title=Citro%C3%ABn_2CV&oldid=1075487050. And also www.carsales.com.au,Seven Tiny Cars to Easily Navigate City Car Parking,https://www.carsales.com.au/editorial/details/seven-tiny-cars-to-easily-navigate-city-car-parking-125107/. [Accessed March 21, 2022].

[48] Corey Rueth, ‘New GM/Segway PUMA and Other Personal Mobility Vehicles’, Winding Road Magazine, 7 April 2009 <Bureau of Statistics, “More than Two in Three Drive to Work, Census Reveals.”> [accessed 20 January 2023]

[49]Massachusetts Institute of Technology, InfiniteMIT | Vehicle Design Summit, online video recording, 2006, 2023 <https://infinite.mit.edu/video/vehicle-design-summit> [accessed 10 January 2023]

[50]Artur GrisantiMausbach, ‘Paradigm Shift: The Aesthetic of the Automobile in the Age of Sustainability’ (unpublished thesis, Royal College of Art, 2010) <https://researchonline.rca.ac.uk/1164/> [Accessed 4 August 2021]

[51]William J. Mitchell, Chris E. Borroni-Bird and Lawrence D. Burns. Reinventing the Automobile: Personal Urban Mobility for the 21st Century(Cambridge, MA: MIT Press, 2010).

[52] Lawrence D. Burns, Autonomy: The Quest to Build the Driverless Car – and How It Will Reshape Our World(UK: Williams and Collins, 2018).

[53] SPACE10,Spaces on Wheels: Exploring a Driverless Future(September 17, 2018)https://space10.com/project/spaces-on-wheels-exploring-a-driverless-future/.

[54]Brad Plumer, ‘Cars Take up Way Too Much Space in Cities. New Technology Could Change That. | The New New Economy’, Vox.Com, 2016 <https://www.vox.com/a/new-economy-future/cars-cities-technologies> [accessed 9 August 2021]

[55]Wikipedia, Robotaxi(March 16, 2022)https://en.wikipedia.org/w/index.php?title=Robotaxi&oldid=1077425241.

[56]Forbes, Tech Start-Up Pix Moving Uses Self-Driving Ideas To Make Flexible Citieshttps://www.forbes.com/sites/nargessbanks/2020/02/09/autonomous-drive-pix-moving/.[Accessed March 21, 2022].

[57]StephenTaylor. ‘Time for NSW to Get a Scoot on E-Scooters’. The Sydney Morning Herald, 25 October 2021. https://www.smh.com.au/environment/climate-change/time-for-nsw-to-get-a-scoot-on-e-scooters-20211020-p591lp.html.

[58]Aarian Mitchell,These Small Cars Can Help Drive the Autonomous Future,(October 5, 2018)https://www.wired.com/story/small-cars-help-drive-autonomous-future/.

[59]Mitchell, William J., Chris E. Borroni-Bird, and Lawrence D. Burns, Reinventing the Automobile: Personal Urban Mobility for the 21st Century (Cambridge, MA, USA: MIT Press, 2010)

[60] William J Mitchell. https://en.wikipedia.org/wiki/William_J._Mitchell notes ‘Starting in 2003, he created the Smart Cities program within the MIT Media Lab. Projects that Mitchell developed as part of the Smart Cities program included GreenWheel, a device that would add electric power to a bicycle; RoboScooter, a foldable electric scooter; and the MIT Car (also called the "CityCar", and developed into the Hiriko), which would be propelled by electric motors built into its wheels. The car and scooter projects were envisioned as being made available for public use at locations in cities, with access and scheduling controlled by computer.[1] The MIT Car was designed to fold up into a more compact shape while parked.[4] Following Mitchell's death, the CityCar Project was continued under the direction of Kent Larson in the Changing Places research group at the MIT Media Lab’.

[61] Burns co-authored Reinventing the Automobile for the 20th Century. His later publication, Burns, Autonomy: The Quest to Build the Driverless Car – and How It Will Reshape Our World. did not make a link between the smaller vehicle and autonomous vehicles.

[62]This comment references the cultural research in PeterWollen,Autopia: Cars and Culture,edited by Joe Kerr. UK: London: Reakton Books Ltd., 2002., and; Bayley, Steven. ‘Cars: Freedom, Style, Sex Power Motion, Colour Everything Is Necessary for the Social History Research’. Slp Series. UK: Conran, 2009

[63]MattWade. ‘How Our Cities Work: Essential Lessons from Lockdown’. The Sydney Morning Herald, 9 October 2021, economy section. https://www.smh.com.au/business/the-economy/how-our-cities-work-essential-lessons-from-lockdown-20211109-p597gn.html.

[64]Commonwealth of Australia, Bureau of Statistics, ‘More than Two in Three Drive to Work, Census Reveals’, Australian Bureau of Statistics (c=AU; o=Commonwealth of Australia; ou=Australian Bureau of Statistics, 2017) <https://www.abs.gov.au/ausstats/abs@.nsf/mediareleasesbyreleasedate/7DD5DC715B608612CA2581BF001F8404> [accessed 2 December 2022]

[65] Therefore, logically, a spatial design investigation should include an ergonomic study of one, two and other combination seated vehicles that are directly related to current transportation trends. This, I would argue, is a more rational approach to transportation than perhaps some of the more orthodox and circuitous city transport planning discourses of the past century.

[66]Karel Martens. ‘Transport Justice: Designing Fair Transportation Systems’, ed. by Miloš N. Mladenović, Transport Reviews, 37.2 (2017), 245–46 <https://doi.org/10.1080/01441647.2016.1258599>

[67]Iris Marion Young, Justice and the Politics of Difference. (Princeton, N.J: Princeton University Press, 1990).

[68] Dr Kara Kockelmanand others. An Assessment of Autonomous Vehicles: Traffic Impacts and Infrastructure Needs. (Texas Department of Transportation Center for Transportation Research at The University of Texas at Austin, March 2017)

[69](Carlino et al. 2013, Andersen et al. 2016, Bajpai et al. 2016, Stiogios et al. 2019)

[70]A spatial investigation, one that addresses environmental justice using smaller vehicle formats and advanced technology is therefore a research aim. The gap in the knowledge base, as identified in this literature review, opens research opportunities.By combining variables previously not combined (smaller CAREV) and a spatial investigation sets up the conditions for spatial experimentation. Importantly, it demonstrates that transdisciplinary research is significant in that it looks wider and with new methods into new areas of investigation.

[71] World Health Organisation, Key Facts: Ageing and health(2022)https://www.who.int/news-room/fact-sheets/detail/ageing-and-health [Accessed 20 January 2023]World Health Organisation statistics (Ibid. 2022) of interest with respect to people living with disabilities and age-related issues are:

·        In 2020, 22% of the world’s population is over the age of 60

·        In 2020, 15% of the world’s population, that is ~1 billion people living with a disability and are regarded as the world’s largest minority

In 2005, 26% of the population of Australia are regarded as persons living with disabilities, comprising 3.96 million people

[72]Alice Haning, Cathy Gazey, and Jillian Woolmer, ‘People with Disability: The Forgotten Road User Group’, Australasian Transport Research Forum, 2012 Proceedings (2012), 18

According to Haning, Gazby and Woolmer persons living with disabilities, 96% of this cohort had public transport in their local area and 68% used it at least once per month. In contrast, 92% of respondents were either a passenger or driver of a private vehicle at least once per month. It can be summarised that between 15% and 20% of the population who are aged or people living with disabilities in the study period in Western Australia (2012) use combinations of public and private transport, with the majority (at least 51%–60%) preferring to use private road transport, as a preference to access services.

[73]Haning ibid p5. In 2009, approximately 80% of people with disability reported being either the driver or passenger in a car in the last trip prior to the survey (ABS 2009b).

[74]Haning ibid p5. The reasons given for the use of private transport were mainly convenience and that it is quicker and/or easier to use than other modes of transport.

[75]Haning p14 People with disability are at higher risk of transport disadvantage compared to people without disability, due predominantly to the impact of their disability on the capacity to access a range of transport modes but also low income and age (Disability Rights Commission 2003).

[76]Haningibid. p3 ‘People with disability have lower labour force participation and educational attainment than people without a disability’.

[77] I have attended ADVI summits in Australia since 2017. Each of these congresses have at least one speaker and a session dedicated to minority and special use groups.

[78]Dr Kara Kockelman and others. An Assessment of Autonomous Vehicles: Traffic Impacts and Infrastructure Needs. (Texas Department of Transportation Center for Transportation Research at The University of Texas at Austin, March 2017)

[79]These cohorts will not be reliant on human drivers, and vehicles will be able to be adapted to the requirements of the disabled person.

[80]National Highway Traffic Safety Administration (NHTSA), ‘Automated Vehicles Policy Statement Concerning Automated Vehicles from 2013’, NHTSA, 2013 <https://www.nhtsa.gov/staticfiles/rulemaking/pdf/Automated_Vehicles_Policy.pdf> [accessed 5 August 2021]

[81]BryanBotello, Ralph Buehler, Steve Hankey, Andrew Mondschein, and Zhiqiu Jiang, ‘Planning for Walking and Cycling in an Autonomous-Vehicle Future’, Transportation Research Interdisciplinary Perspectives, 1 (2019), 100012 <https://www.academia.edu/40396389/Planning_for_walking_and_cycling_in_an_autonomous_vehicle_future> [accessed 9 August 2021]

[82]Hua Sha, ‘Investigating the System-Level Performance of Connected and Autonomous Vehicles against Transport and Broader Societal Impacts’ (unpublished School of Design and Creative Arts, Loughbrough University, 2020) <https://repository.lboro.ac.uk/articles/thesis/Investigating_the_system-level_performance_of_connected_and_autonomous_vehicles_against_transport_and_broader_societal_impacts/13342064/1> [accessed 3 August 2021]

[83]Arnfield, “Two Decades of Urban Climate Research.”‘Spatial, material and airflow patterns effects the results of modelling and the results of UHI modelling remain diverse and inconsistent across software and industry platforms. Additionally, urban roughness and materiality parameters further impact the results.One advance that is evident since the 2003 publication is that standardised climatic data for inputs into the software is now readily available this brings about input data stability which in 2003, appeared to be inconsistently applied.’

[84]Mohammad Harmay, Nurul Syahira, Daeun Kim and Minha Choi, ‘Urban Heat Island Associated with Land Use/Land Cover and Climate Variations in Melbourne, Australia’, Sustainable Cities and Society, 69 (1 June 2021), 102861 <https://doi.org/10.1016/j.scs.2021.102861>.

[85]TRL The Future of Transport, ‘GATEway Project’, TRL, 2017 <https://trl.co.uk/projects/gateway-project> [accessed 5 August 2021]

[86]I used a Universal Thermal Climate Index for this study. Please refer:

Zare, Sajad, Naser Hasheminejad, Hossein Elahi Shirvan, Rasoul Hemmatjo, KeyvanSarebanzadeh, and Saeid Ahmadi,‘Comparing Universal Thermal Climate Index (UTCI) with Selected Thermal Indices/Environmental Parameters during 12 Months of the Year’, Weather and Climate Extremes,19 (March 1, 2018), 49–57. https://doi.org/10.1016/j.wace.2018.01.004.

[87](Alexander et al., 2018; Fischetti, 2018; Baston et al., 2019; Endreny, 2019; Hannam, 2021)

[88]     The study looks at the active transport sector as an environmental approach.