Contributions” focuses on key challenges associated with the effective development and use of indicators to assess sustainability in the transport sector. With the expectation that learnings from the indicator
frameworks literature can also serve to inform other types of decision-support processes and transport assessment tools, I analyse first the state-of-the-art with regard to the design and use of STIFs. One
implication from the findings of article I is that the three metaframework functions also served to inspire the analytical framework – the three challenges - presented earlier. I refer to these below to further qualify the contribution of each of the remaining articles.
Purpose
52 The purpose of article I is first to clarify the key functions of indicator frameworks, and second to develop a metaframework for what should inform the analysis and eventually the design of STIFs (independently of whether they are intended for application in ex-ante, monitoring, or ex-post measurement).
53 Many sets of indicators have been proposed to assess sustainable transport, and the literature points to specific weaknesses, but it does not provide a broad or systematic approach for assessing STIFs. Context also matters: despite the overarching concern for sustainability, different contexts have different goals, different needs, and access to different data. The premise is therefore that it is preferable to develop guidance – a list of criteria - for analysing or designing indicator framework rather than attempt to provide a single, universally applicable indicator framework. There is therefore a need for a type of overarching frame – a metaframework32 - to assess STIFs.
Method and findings
54 By analysing the research results from seminal literature on STIFs, the three functions of conceptualization, operationalization and utilization were found to provide a logical structure for analysing existing or
emerging indicator frameworks, and therefore to produce a set of metacriteria to fulfil that purpose. Starting from an initial list of seven ‘characteristics for robust indicator frameworks’ by Pei et al. (2010), the article identifies and describes a total of 21 ‘metacriteria’ that are grouped based on the framework function they are (most) contributing to.
55 Conceptual criteria include for example “Adopting an explicit, comprehensive, and holistic view on sustainability”, “Allowing a long time horizon” and “Ranking of sustainability impacts” – all essential characteristics of a robust STIF. The research emphasises the need for embedding STIFs in a strategic sustainability planning process that would incorporate dimensions and aspects of sustainability from the start, rather than trying to adapt already existing indicator frameworks (e.g. for system optimization or government performance) to assess ‘sustainable transport’.
56 Operationalization criteria used to inform the design and selection of indicators in general is a
well-researched field. For assessing sustainable transport, long list of impact indicators are readily available (Hall 2006; Litman 2015; Marsden et al. 2005) and conditions for their selection has been covered elsewhere (Gudmundsson et al. 2016). The criteria raised here are applicable to indicator frameworks in a more general
32 As De Neufville (1978) points out, there is a risk of ‘infinite regress’ in creating a framework to validate another framework. Yet this is needed because there are no commonly agreed set of criteria for how to measure and report on transportation sustainability.
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sense (e.g. “Ensuring cost-effectiveness or monitoring”) rather than specifically addressing sustainable transport indicator frameworks. These are nevertheless important as a type of sanity check, and they informed the methodological decisions in the later articles.
57 Utilization criteria examine the use and influence of tools in the context of transport planning and decision-making. For example the criterion “Engaging with stakeholders and context” is found to be particularly relevant in a wider process of sustainability appraisal. This also becomes a key concern in the following two articles of this thesis.
Selected research paths
58 The metaframework also opened up wider issues relevant for other assessment and decision-support tools33. This led me to focus on examining primarily issues related to the conceptualization of sustainability in STA, namely: prioritising sustainability impacts (articles II and III); adopting a comprehensive view on
sustainability (article III); identifying and capturing trade-offs between impacts in the long term (article IV);
and informing strategic sustainable transport choices (article V). In other words, the metacriteria found in this research opened up new research avenues, both for indicator research but also beyond it.
59 One avenue for further investigation is the actual application of the metaframework to assess existing frameworks e.g as used by transport agencies, to review how well they reflect and support different aspects of sustainability. More operational criteria for such a task were not developed in the thesis, but could be a topic for future research. This work can for example consist of examining empirically existing, state-of-the-art STIFs (such as CEEQUAL in the UK or INVEST in the US) in order to further develop the theory and the applicability of each metacriterion.
1.6.2 Article II - Operationalising a sustainability viewpoint in STA
60 Based on one of the research gaps found from the review in article I, in article II “Applying Sustainability Theory to Transport Infrastructure Assessment Using a Multiplicative AHP Decision Support Model” we investigate the prioritisation of impact indicators by the use of Multi-Criteria Analysis (MCA) methods.
Purpose
61 There is yet limited literature on the issue of prioritising impacts from a strong sustainability perspective in integrated assessment of transport projects. Holden et al. (2013) offer one such recent contribution based on principles from the Brundtland report. Jourmard and Nicolas (2010) suggest an approach based on the nested model that avoids substitution between the three traditional pillars of sustainability, where they also single out irreversible impacts on biodiversity and the climate. Robèrt et al. (2016) develop a stakeholder
engagement approach based on the Natural Step sustainability principles (see Chapter II for more details on these foundational sustainability theories). Article II contributes to this topic by developing a method to integrate explicitly strong principles of sustainability as a means to inform the weighing of transport effects in a real appraisal context.
33 The idea that metacriteria relevant for STIFs could also be relevant for decision-support processes and assessment tools in STA in general emerged at the Transportation Research Board general conference in January 2015. The Sustainability Research Subcommittee suggested we present the metaframework as a basis for framing future research on knowledge tools, guidance or even standards for how to incorporate sustainability in transport governance.
http://www.trbsustainability.org/wp-content/uploads/2012/11/ADD40_Sustainability_Research_Subcommittee-_MinutesFinal.pdf
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62 This research examines a specific transport infrastructure project (a bridge in Denmark) using an existing set of eight assessment criteria drawn from this specific case. In this article, we operationalise sustainability by providing a simplified model of strong sustainability where each of the three conventional dimensions (economic, social and environmental) are nested. We compare this model to the principles set by the
Brundtland report to clarify the strengths and weaknesses of this approach. We then devise and apply a MCA procedure to make explicit a sustainability viewpoint using both the nested model and input from a green think-tank to use as comparison. Part of the procedure involves the assessment of complex impacts using a pairwise comparison technique to assess the relative performance of various options to the main scheme proposed.
Findings
63 The nested model is found to be a useful approximation of strong sustainability when used as guidance for prioritising impacts (at the condition that the impacts assessed are all relevant, as is the case here). The outcome is however not intended to be used ‘as is’, but instead to provide a type of benchmark for comparing preferred project options between ‘virtual sustainability advocates’ and the perspective
represented by the interests of decision-makers in this particular context. Two more practical conclusions are of particular relevance for the research that follows in article III. First this case raised the need for a wider (and perhaps standard) set of assessment criteria to be used in sustainable transport appraisal. Second, because of the need to involve experts, decision-makers and stakeholders as part of the assessment process, the approach showed the potential for the communicative role of MCA-based tools in a process of appraisal.
1.6.3 Article III – Expanding the sustainability viewpoint in STA
64 Article III “Incorporating a sustainability viewpoint into multi-actor MCA – the case of HS2”, is motivated by the conclusion from article II for the need to expand the assessment criteria to a wider and more
comprehensive set of impacts. We develop this research path by examining a different type of transport infrastructure project (high-speed rail).
Purpose
65 The main focus and contribution of this article is to develop and test a STA process on a large transport project. This article is a core part of this thesis both in terms of breath and depth: by developing a full STA method, we seek to incorporate sustainability by: 1) developing a comprehensive list of sustainability assessment criteria; 2) adapting and applying the multi-actor MCA (MAMCA) procedure; and 3) making explicit a sustainability viewpoint in three different ways34. One main objective of the research is to expand the instrumental rationality of assessment tools by integrating various stakeholder perspectives in a
systematic manner. Therefore the article is mainly concerned with exploring the various methodological trade-offs that have to be made while still addressing conceptual challenges (validity of the data both from a scientific and a sustainability perspective), operational challenges (transparency, ease of use and cost-effectiveness), and procedural challenges (potential for reflexivity and influencing decision-making)35.
34 This paper is longer than a single journal article. It describes a substantial research project that represents a major portion of my doctoral research which, we think, has the potential to contribute to several publications. A shorter version of this paper is currently in the review process.
35 These criteria are a subset of those developed in article I, adapted and simplified for this case.
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66 The first phase of the HS2 project (between London and the West Midlands) is selected as a case study for a number of reasons. A high-speed rail project of the scale of HS2 has potential to alter the space-time
geography of the UK significantly, which brings a number of wider environmental, social and economic impacts that are difficult to assess with standard assessment methods. For this reason HS2 is an opportunity to examine sustainability in the context of transport appraisal in more detail. In this case, the existing state-of-the-art appraisal guidance of the UK was stretched and substantially discredited, leaving the actual decision-making of HS2 to a more arbitrary political process (Dudley and Banister 2015). On the other hand, a vast amount of data and documentation is readily available from the actual appraisal that took place, making it easier to reproduce and test, ex-post, an alternative appraisal process.
67 The method we develop draws from the MAMCA approach, a MCA method that gives an explicit concern to various stakeholder perspectives (Macharis, Turcksin, and Lebeau 2012). We follow and adapt standard MCA appraisal steps, which are summarised here:
1) The definition of the project objectives and options are predetermined based on the case study itself;
2) The list of criteria (impacts) was developed iteratively and interactively in the first phase of the research with interviews and by the research team;
3) The research team developed criteria for grouping stakeholders by interest; all stakeholders interviewed are transport professionals familiar with HS2, and a future generations viewpoint is obtained by eliciting the views of sustainability experts;
4) The selection, prioritisation and assessment of the criteria is done by conducting structured interviews based on an online questionnaire. The choice to carry out the response elicitation in person is motivated by the need to address known biases with this type of methodology (e.g.
motivational bias);
5) The data analysis is conducted by the research team based on the multiplicative analytical hierarchy process (AHP) technique;
6) Robustness of the results is tested by varying consistency thresholds and the minimum number of assessments per criterion to be considered valid;
7) Project preferences are computed for all stakeholder groups, but they are not aggregated. For purpose of comparison, ‘virtual’ sustainability viewpoints are computed by applying weights for weak and strong sustainability (as was done in article II).
Findings
68 The key contribution of this paper is the incorporation of a ‘future generations’ stakeholder into the
MAMCA process. In this case, neither the ‘bottom-up’ sustainability expertise viewpoint nor the ‘top-down’
virtual sustainability viewpoint comes out in favour of HS2 when compared with the option of upgrading the existing network. At a methodological level, the research demonstrates the usefulness of conducting semi-structured interviews in conjunction with an online questionnaire for the process of assessing and weighting a long list of sustainability impacts. The approach also provides a means of quantifying wider impacts relevant for STA, thereby making them visible and comparable.
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69 The research also led to a number of more detailed findings with regard to the adaptation of MAMCA to this complex case, which can be summarised as follows. Validity for sustainable transport appraisal requires comprehensiveness in the long list of relevant impacts, and therefore criteria and their descriptions are cornerstones of the method (the considerations that led to the final list we used are explained in more detail in the paper’s second appendix). While most respondents felt comfortable with the approach, some
respondents expressed the need for exploring further how to decouple normative importance from contextual relevance in the assessment of the alternatives. Another important finding is the need for clear rules for grouping stakeholders into homogeneous groups, and therefore particular attention needs to be given to obtaining sufficient information on respondent traits. As MCA methods depend more directly on human judgment, validating who and how the questionnaire is answered is crucial to mitigate biases.
70 A final important finding is the potential for this approach to play a significant role in communicative forms of planning and decision-making. The process allowed the research team to experience reflexivity and learning on the part of respondents. Respondents realised the implications of their choices, which in some cases challenged their preconceived ideas on this specific case. This could be relevant in an actual STA process for reaching a greater consensus in decision-making, and therefore addressing the issue of
“unstructured stakeholder involvement and inefficient public participation” raised by Soria-Lara et al (2016).
1.6.4 Article IV – Biodiversity loss and climate in STA
71 Continuing with the case of high-speed rail, in article IV “High Speed Rail: A Mandate for Future
Generations?”, we turn to analysing in more detail the challenges and trade-offs associated with assessing two interrelated environmental impacts for large transport projects, namely the two core planetary
boundaries of climate change and biosphere integrity.
Purpose
72 In this article, we seek to answer the following research questions: 1) what are the difficulties of assessing jointly carbon and biodiversity impacts in the long term?; and 2) to what extent are these impacts given political salience in the decision-making of large infrastructure projects like HS2?
Method
73 Drawing from the concept of environmental planetary boundaries (Steffen et al. 2015), article IV explores in more detail the longer term environmental consequences of major infrastructure decisions that have to be made today. The article is based on the case of high-speed rail in the UK (the HS2 project phase I), which is used to illustrate the various complexities in assessing the two critical boundaries of climate and biodiversity.
We then zoom in on the tunnelling of a protected area in the Chiltern Hills in order to illustrate the inherent difficulties in defining – let alone prioritising – an environmental legacy for future generations.
Findings
74 The actual appraisal of HS2 provides extensive data on both the operation and construction carbon footprint of the project. However we find that the claimed carbon savings of the full HS2 project (phase I+II) over the appraisal period of 60 years are likely to be offset entirely by the embedded footprint from construction.
Much of the construction footprint comes from tunnelling (due to the steel and concrete required). From a biosphere integrity perspective, increased tunnelling reduces the impact of natural habitats, which is particularly relevant when dealing with local ‘irreplaceable’ natural capital such as ancient forests. But this brings global implications due to the significant upfront carbon emissions from tunnel construction
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75 An important issue here is timing. While the actual numbers are sensitive to choices in terms of future scenarios, HS2 is found to be essentially ‘carbon neutral’. However, the construction footprint comes at an upfront ‘cost’, whereas the ‘benefits’ - which come mostly from a forecast of modal shift - will only start accruing once the line is operational. One implication is that HS2 will contribute negatively to the UK carbon budgets reductions until 2050.
76 Faced with such trade-offs - and despite a voluminous environmental impact assessment - we find that considerations for speed and costs take priority, whereas wider environmental questions are given a subsidiary role. In the appraisal process, there were no discussions over the adequate balance between climate and biodiversity impacts
77 This conclusion is relevant as a reflection about the three challenges: precise definitions and ambitions in terms of biodiversity, legally binding goals in terms of climate, and precise qualitative and quantitative assessment data on both carbon and biodiversity impacts do not suffice by themselves to guide a
sustainability transition. This research therefore stresses a weakness of the WebTAG assessment framework:
although individual impacts are assessed thoroughly for the expected lifetime of the project and even beyond (60 years, 120 years for some impacts), the framework lacks a formal way to report the evolving dynamics between impacts, to present explicitly the trade-offs that are involved, and to agree on their appropriate balance.
1.6.5 Article V – The concept of reasonable travel time in STA
78 Finally, in article V, “From Minimum to Reasonable Travel Time”, we revisit the concept of travel time in transport planning and develop the concept of Reasonable Travel Time (RTT).
Purpose
79 The main purpose of the article is to adopt a critical view on the historic emphasis for minimising travel time in transport planning, and to contribute to a better understanding of the value of travel time from a traveller’s perspective. The key assumption behind this approach is the concept of derived demand: transport in this view is seen as a ‘means to an end’. In economic terms, it is the benefits (or the utility) derived from the activities at destination that justify the costs (or disutility) of travel. The main implication is that travel time is considered ‘lost’36. This in turn puts times savings at the centre of transport analysis which drives
development of transport solutions that speed up travel.
80 The aim of the article is to enrich (and to some extent challenge) the current planning paradigm by developing a more holistic conceptualisation of travel time for informing strategic sustainable transport choices in transport appraisal.
Method
81 The article starts by deconstructing the various elements that compose travel time. Journey durations play an important role in travel decisions. But from a traveller’s perspective, it is the total journey time that matters – the door-to-door travel time - which often can involve more than one transport mode. In contrast, the
transport system is typically planned as a set of separate networks. A second important aspect is the need to
36 Or ‘wasted’, or ‘locked’, although time spent travelling could also be seen as time ‘invested’, which has a less negative connotation. The exact terminology to use in future versions of the article was still being discussed at the time of submission of this thesis.
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reconsider to use of time while traveling, particularly so in a technology-enabled age. Some economic tools
reconsider to use of time while traveling, particularly so in a technology-enabled age. Some economic tools