Identifying Early-Stage Risks to High-Speed Rail: A Case Study of the Sydney–Newcastle Corridor, Australia

Abstract

High-Speed Rail (HSR) has long been proposed as a transformative infrastructure project for Australia; yet, despite multiple feasibility studies and significant government expenditure, it remains unrealized. This study investigates the key barriers preventing HSR implementation. To achieve this, a novel mixed-methods approach that triangulates a comprehensive literature review, in-depth expert interviews, and broad stakeholder survey was employed. The Analytic Hierarchy Process (AHP) was used to quantify the relative importance of the identified barriers. Simultaneously, qualitative insights were gathered through interviews with industry leaders, government officials, and infrastructure experts. This dual approach provided a comprehensive understanding of the challenges. The findings highlight the importance of external factors. These include political uncertainty, financial constraints, and systemic logistical challenges, which go beyond technical feasibility. Based on these insights, this research identifies critical early-stage risks and contributes to a re-evaluation of HSR not solely as a transport solution but also as a vital tool for regional development. Refining cost and time estimation methodologies using reference class forecasting, fostering proactive political engagement to secure bipartisan support, enhancing private sector collaboration through early contractor involvement and risk-sharing mechanisms, and developing a national upskilling framework to address workforce shortages were also key findings. The study has garnered industry recognition and support, with experts acknowledging its contribution to the ongoing discourse on HSR implementation in Australia.

1. Introduction

1.1. Introduction to Research Topic and Significance

1.1.1. High Speed Rail (HSR) Status in Australia

Many publications attest that high-speed rail presents a generational opportunity for Australia to boost economic productivity [1,2,3,4]. The project was initially conceptualised by the Commonwealth Scientific and Industrial Research Organisation’s “Very Fast Train” proposal in 1991 [5]. Since 1991, several feasibility studies have been conducted, with the government incurring cumulative expenditures exceeding $100 million [6]. Yet, HSR has not materialised in Australia [7].

Internationally, countries that now lead in HSR also encountered significant challenges in their early development phases. In Japan, a surge in demand along the country’s primary rail corridor during the early 1950s created an urgent need for expansion. However, upgrading the existing tracks was deemed impractical, leading the President of Japanese National Railways to spearhead the development of the Shinkansen—Japan’s first HSR project. The proposal faced strong opposition at the time, particularly as Japan was still recovering from World War II [8].

Similarly, post-war France sought to modernise its railway infrastructure. Japan’s Shinkansen’s success influenced the Train à Grande Vitesse (TGV) development, yet the project faced considerable opposition. The French regional development authority DATAR opposed HSR in favour of the Aérotrain, an air-cushion vehicle developed in France. Despite resistance from regional groups, the strong advocacy of the Prime Minister and President led to the TGV’s inclusion in the national economic plan, ensuring its eventual development [9].

Spain’s HSR system also encountered early setbacks. In the 1970s, an initial feasibility study deemed the project unviable due to high costs and insufficient projected traffic [10]. However, by the late 1970s, a new line was proposed to address capacity issues between Madrid and Seville [11]. Although the original plan did not include an HSR alignment, modifications during construction ultimately led to the development of Spain’s first HSR line, which opened in 1992. Following its success, Spain introduced the 2004 Master Plan, aiming to expand the network to 7200 km by 2020. This initiative sought to enhance accessibility, compete with air travel, and position 90% of the population within 50 km of an HSR station [10].

Despite these international precedents, Australia has yet to overcome the barriers preventing HSR implementation. To address this, the recently established High-Speed Rail Authority (HSRA) was tasked with reinvestigating a Sydney to Newcastle HSR alignment, with the government committing $78.8 million towards this feasibility study [12]. To ensure the feasibility study yields tangible outcomes, it is crucial to identify and address barriers to implementing HSR in Australia.

1.1.2. Research Environment

For a broader context, Australia has four major public infrastructure sectors: social infrastructure, energy, communication, water, and transport. Within the transportation sector, infrastructure projects predominantly fall into the categories of roadways, waterways, aviation, or railways. The HSR project falls within the railway categories and adjunct services, such as suburban/regional rail, freight rail, and metro/light rail, all of which are currently available in New South Wales (NSW). This research focuses on HSR development within the transport sector. The sector drives Australia’s nation-building by connecting major cities and boosting economic productivity. Beyond these financial advantages, the physical and highly visible nature of transport infrastructure, including HSR, engages public interest and generates a demand for regular assessment.

1.2. Research Justification and Objectives

The impact of HSR in Australia is undisputed, and yet it remains a pipeline dream. The reasons for stagnation are believed to be a lack of economic benefit. However, the Australian government has committed to other large-scale projects without meeting all theoretical feasibility requirements, indicating that HSR projects encounter unique, undocumented barriers, particularly, in the post-feasibility, pre-implementation phase. Suburban Rail Loop, for example, has a Benefit Cost Ratio (BCR) of 0.6–0.7 according to The Parliamentary Budget Office’s latest assessment [13], yet it was approved and is currently under delivery. Hence, the specific, prioritised reasons for stagnation in the Australian HSR context are still unknown and under-researched.

This study is motivated by a theoretical and empirical gap in understanding why HSR, despite strong global precedents and technical feasibility demonstrated in various Australian studies, repeatedly fails to transition from concept to delivery. The research proposes that a more structured, multi-dimensional approach is needed to identify, analyse, and prioritise these barriers. Accordingly, this research aims to uncover the key factors hindering HSR progression beyond conceptualisation and to propose actionable recommendations to overcome these obstacles. The study’s novelty lies both in its focus on the Sydney–Newcastle corridor—a priority identified by Infrastructure Australia—and in its methodological contribution. By employing a mixed-methods design that integrates literature review, expert interviews, stakeholder surveys, and the Analytic Hierarchy Process (AHP), the research produces a systematically prioritised framework of barriers. This provides a more rigorous and decision-ready analysis than what is typically achieved through qualitative or non-integrated approaches, offering actionable insights for policymakers, infrastructure agencies, and the High-Speed Rail Authority (HSRA). Specifically, the study seeks to achieve the following aims:

• Identify barriers that specifically prevent the realisation of HSR in Australia;
• Document potential challenges unique to implementing HSR in the Sydney-to-Newcastle corridor;
• Develop industry-ready recommendations to overcome identified barriers and facilitate successful HSR implementation.

1.3. Research Scope

Figure 1 outlines the scope of this research, which focuses on the institutional, political, and implementation-related factors contributing to the stagnation of HSR development in Australia. Rather than re-assessing technical feasibility, the study aims to highlight systemic and context-specific barriers that impede progress—particularly those that arise after initial feasibility studies are completed.

The structure of the main body of this research is outlined in Figure 2 below. The next section provides a literature review, examining secondary data to address the research objectives.

2. Literature Review on the Australian HSR Risks and Barriers

This research aims to synthesise secondary data on the implementation risks associated with HSR in Australia. The literature review leverages peer-reviewed academic journals from repositories such as Google Scholar, the University of Sydney library, and ResearchGate. This study will also incorporate insights from news articles to generate themes and ideas. Only credible information will be extracted from these news sources and validated with academic publications to remove biases. Moreover, scholarly articles and journals authored by corporations with substantial experience delivering HSR projects globally will also be analysed for insights.

2.1. Alluring Potential of High-Speed Rail in Australia

Complex megaprojects, such as HSR, have a profound impact on societal structures. This impact spans technological, economic, political, and aesthetic dimensions [14,15]. As of 2018, 22 countries had established HSR, with an additional 13 countries poised to join [16]. Yet, HSR in Australia only appears in feasibility studies. Recent studies, like the 2013 High-Speed Rail Study, highlight HSR’s potential to reduce travel times, such as the 40 min journey between Sydney and Newcastle [5] compared to over 120 min by road and 180 min by air (including travel to and from airports). These improvements enhance connectivity and offer opportunities to address housing challenges through satellite developments [3]. These are factors that the HSRA must capture in its upcoming feasibility study to ensure success. A Sydney to Newcastle HSR alignment further stimulates business growth along the Eastern corridor, attracting both tourists and business travellers, as highlighted by Catherine King, Minister for Infrastructure [17]. Authors Chen and Hall [18] agree that the UK’s HSR alignment improved accessibility and attractiveness for tourists by reducing travel times and enhancing connectivity between destinations. Hence, similar benefits can be expected for Australia’s Sydney-to-Nastenburg alignment.

Vickerman [19] further notes that introducing HSR transforms traditional commuting methods and contributes to the aesthetic sublime, as argued by Flyvberg [14]. Vickerman states that the shift would transform conventional practices like fly-in–fly-out and drive-in–drive-out to a streamlined and comfortable train-in–train-out commuting system [19]. Authors Chen et al. [19,20] further attest to this, where their study conducted in China concluded that the transition to HSR reduced reliance on traditional commuting methods such as car and air travel. Similarly, an Australian government study found that HSR could lead to a “positive transformational effect on how most Australians live, work, and travel” and “has the potential to be an integral part of Australia’s future” [21]. The evidence of HSR’s benefits to commuters is widely argued and accepted in the literature.

The above-improved connectivity also contributed to the wide-reaching economic benefits of HSR, such as increased productivity, labour market expansion, and regional economic growth, argued Vickerman, Chen and Hall [18,19]. The broader economic benefits stemming from these societal impacts are substantial. For instance, Spain’s comprehensive HSR network over 24 years yielded substantial savings of approximately €4.286 billion due to reduced pollution, accidents, and positive climate change impacts [1,22]. In the Australian context, a study by the University of Wollongong emphasised the potential for HSR to generate a “massive boost to the Australian economy that would be difficult to achieve in any other way” [23]. Hence, the literature agrees that the benefits of an HSR alignment are substantial, yet the reasons for the lack of implementation are still unknown.

2.2. Cost Barriers in Implementation and Delivery

The recent HSR study had projected the delivery cost to be $114 billion in 2012, equating to $152 billion in 2024, positioning it as Australia’s most significant infrastructure investment if undertaken [5,21]. This represents a substantial investment even when viewed over a nominal 30-year project span. In a study conducted in the USA, Albalate and Bel [24] discuss how the high capital costs of HSR infrastructure pose a significant barrier, especially in countries with tight budget constraints. The study also examines case studies where financial challenges hindered HSR development. A further study conducted by Campos and de Rus [25] collected information on 166 HSR projects worldwide. They also presented that the high construction and land acquisition costs were frequently cited as major obstacles, particularly in countries without established HSR infrastructure, like Australia [19,24,25,26].

Exacerbating this challenge, the literature notes that cost estimates during the conceptualisation phase tend to be unreliable [27,28], with megaprojects commonly experiencing cost overruns and schedule delays. Examples include the Metro project ($12 billion, 5 years delayed [27]) and Victoria’s big build projects such as the Northeast Link ($10.3 billion [29]). This is a further barrier to HSR approval in Australia. David Cochrane, Senior Vice President at WSP, suggests window and range-based budget estimates, claiming absolutes will always be wrong [2]. Renowned mega projects researcher Bent Flyvberg is also in agreement that range or window-based estimates are most suitable [14,26,30].

A 2017 study analysing public infrastructure megaprojects attributed cost overruns to various factors, including environmental concerns, claims and penalties, procurement challenges, and scope modifications [31], a notion supported by a recent University of Sydney investigation into the causes of the Sydney Metro cost escalation [32]. A Sydney Light Rail project case study confirms that unforeseen claims can particularly threaten cost control. In this project, undocumented utilities led to a substantial payout by the NSW Government [33,34].

2.3. Engaging the Private Sector for Successful Delivery

The HSR scoping study prepared for the Department of Infrastructure and Transport [35] notes significant gaps in domestic expertise, resources, and workforce capability for HSR delivery. This also aligns with Infrastructure Australia’s “Infrastructure Market Capacity Report” [36]. This study, conducted by AECOM (the engineering consultancy that delivered the report), found that the priority success factor in the first year of operation is the “timely delivery” of the HSR project [37]. However, this is only possible if the private sector can design and build an HSR alignment in Australia. Experts support the idea that the private sector’s delivery capability and solvency are important considerations [2,38]. Insights from the High-Speed Rail Advisory Group [21] propose releasing the project to global tenders to potentially reduce costs by 20% and mitigate delivery concerns through international expertise due to a notable lack of domestic workforce expertise.

A similar capability-driven issue was highlighted in the independent review of the Inland Rail project. The board and its subcommittee claimed not to have adequate skills to oversee the conceptualisation of the project [39]. This led to a $15 bn cost blowout. This was substantiated by Bent Flyvbjerg, who mentioned that the lack of accurate information in the conceptualisation phase results in inaccurate estimations and baseline cost overruns. This ultimately results in “reality catching up with optimistic, or manipulated schedules, costs or benefits” [14], as observed in the Inland Rail project.

2.4. System Integration and Feasibility

Many publications call for widespread system integration to realise the benefits of HSR in Australia [2,40]. System integration is divided into two categories: the integration of the HSR network with current and future infrastructure pipelines and the integration with suburban/regional rail. This is difficult in Australia because each state has its own rail network, with different rolling stocks and infrastructure. Glazebrook [40] advocates for integrating HSR with existing rail infrastructure, citing its effectiveness in staging and providing early benefits. Glazebrook concluded that this integration is projected to serve approximately 75% of the Australian population, a similar figure of 69.2% corroborated by Anthony Green [41].

Glazebrook raises concerns about the added topographical challenges in the Sydney to Newcastle route, the “most difficult” in the Eastern Corridor [40]. As the High-Speed Rail Authority proposed, it would possess an unfavourable benefit–cost ratio if it were to be implemented as a stand-alone network in the first phase. The High-Speed Rail Study conducted in 2013 [5] agrees that the Sydney to Melbourne route has a greater economic rate of return. However, it would need to be delivered in 2 phases (Sydney to Canberra and Canberra to Melbourne). This requires greater investment, which would substantiate the decision to opt for the lower-cost Sydney to Newcastle route instead, albeit with greater risk. This coincides with Hirschman’s principle of the “Hiding Hand”, that “nothing would ever get built if people knew the real costs and challenges involved” [14,42]. The decision to investigate the Sydney to Newcastle route is a significant risk, preventing the realisation of HSR in Australia.

3. Materials and Methods

This research includes both a literature review and primary research, guided by the Convergent Parallel Design [43], as illustrated in Figure 3. The research employs a mixed-method approach for collecting and analysing primary data. While studies on the feasibility and implementation of HSR are common in the industry, the literature reveals a gap: the reasons behind the lack of realisation following the completion of feasibility studies in Australia are not well-researched. This gap highlights the need for further exploration, as identified in the literature review.

A central element of this study’s contribution to knowledge is its methodological innovation. This research introduces an innovative approach in combines the Analytic Hierarchy Process (AHP) method with qualitative interviews and a literature review in the context of HSR research. This combination has not been extensively explored in the literature on HSR implementation, particularly for systematically prioritising perceived barriers. The methodological triangulation approach allows for both the quantification of stakeholder concerns and the discovery of novel insights through expert interviews, thus bridging a key gap in the current body of research [44,45,46]. This approach provides a more robust theoretical foundation for understanding and addressing project barriers than singular methods alone.

This research is grounded in a comprehensive review of relevant academic literature. Decile 1, peer-reviewed journals were browsed and cited appropriately. Given the lack of research on the implementation of HSR, particularly in Australia, suitable grey literature, including government reports, conference proceedings, and news articles, has also been reviewed. However, particular care is provided to remove biases and opinions in these data. Themes gathered from grey literature are also cross-referenced with academic literature to ensure validity, as shown in Figure 4 below.

Following the literature review, when notable gaps are identified, a mixed-methods approach is employed to gather primary data through interviews and surveys, aiming to fill these gaps. This mixed-methods integration enables a more comprehensive understanding of barriers by quantifying stakeholder priorities while capturing rich, contextual insights from expert interviews. This methodological triangulation not only strengthens the validity of findings but also bridges theoretical frameworks with empirical evidence, addressing the common gap in HSR literature where studies focus narrowly on technical feasibility or stakeholder opinion in isolation. The research methodology flow chart is shown in Figure 5 below.

3.1. Primary Survey Data

In this research, a survey was conducted to gather the opinions of relevant professionals from the infrastructure and transport industry. As the survey target population was diverse and large, the questions comprehensively covered all aspects of the HSR domain. There were 51 multiple-choice questions based on the Likert scale, Boolean options, or general multiple-choice, comprising the following categories:

• Participant Information—The survey could be undertaken anonymously to reduce the barrier to participation. Hence, tracking the participants’ information was crucial for making informed analysis decisions;
• General Questions—These questions pertained to the HSR domain in general;
• HSR Benefits—These questions aimed to capture the general benefits participants expected to realise following the implementation of HSR. This was also used as a control to capture any biases due to individuals who benefit an extraordinary amount;
• Barriers to Implementation—This section aimed to capture the participants’ perceived barriers to HSR implementation;
• Concept Phase Risks—This section aimed to capture project management-related risks, particularly from participants working in the industry’s management space;
• Contract Structuring—This section aimed to capture the participants’ sentiment towards a PPP and alternative traditional procurement methods;
• Other categories of questions focused on nuanced barriers to the implementation of HSR.

Note that, due to the nature of the survey, the expertise of the survey participants cannot be validated; therefore, control questions were embedded. These control questions prompt a response that is already answered through a literature review. A comparison of these control questions ensures that participants are suitable candidates for the survey. Following Bruner’s Marketing Scales Handbook [47], the questions were formulated to avoid further unintentional biases.

The survey was designed using the University of Sydney’s Qualtrics platform to comply with the relevant privacy policy. Qualtrics is also easy to use and presents a professional appearance to participants. QR codes and shortened URLs were obtained and shared with the author’s professional network. This was notable in engineering consulting, construction, and academia.

The rigid survey structure, developed using the Marketing Scales Handbook, ensures a prominent level of repeatability should this research be reinvestigated. The survey data can only be used to compare and validate existing literature. In a research domain such as HSR, primary research is required to address the existing literature gap rather than merely validating it. This is a notable limitation of the survey. Hence, interviews were also employed in this research.

3.2. Primary Interview Data

Interviews were employed to collect primary data in this research, aiming to generate new ideas and bridge the existing literature gap [48]. The pool of interviewees, expanded through referrals, formed a well-rounded set of primary data. These individuals were contacted directly for an interview.

The interviews were semi-structured in format. This is when a skeleton of questions follows a rough structure, but the interviewees are not mandated to stick to the questions being asked alone. This allowed the research to explore topics in more depth while covering a consistent set of questions [49]. Jamshed’s [49] findings concluded that this format allows the exploration of complex topics such as HSR and enables rich data collection. These interviews can also help discover ideas that can be explored in future research.

• The interviews consisted of 21 questions developed using the Marketing Scales Handbook by Bruner [47] to avoid further unintentional biases. To further mitigate bias, questions were piloted and reviewed for neutrality, recognising that the research team’s engineering background could influence framing or interpretation. They comprise the following consistent question framework with all participants asked the same set of core questions across three themes: General Questions—These were preliminary questions surrounding the HSR domain in Australia;
• Concept Phase Risk Questions—These questions were to capture the notable management risks and concerns associated with a mega project of this nature;
• Other categories of questions focused on nuanced barriers to HSR implementation.

The interviews conducted as part of this research ranged from 60 to 90 min and were conducted either in-person or remotely via Teams or Zoom. The interviews were recorded so that the transcripts could be reviewed afterwards. Note that the repeatability of the interviews is limited due to their semi-structured nature. However, future researchers will benefit from a more diverse perspective, thanks to a larger sample size that will significantly supplement the data collected in this research.

3.3. Implementation Limitations and Risks

Conducting primary research for this research required obtaining ethics approval from a designated academic body. Implementing a survey in addition to interviews, as initially planned, helped gather quantitative primary data efficiently. One key limitation of the survey was its length, which took approximately 10 min to complete. This resulted in a risk of participants losing interest, which led to a high percentage of incomplete responses on the Qualtrics platform.

The research aimed to interview nine well-established industry experts in the transport and economic development sectors. The small sample size also introduced the possibility of skewed data, as the experts shared similar interests and expertise. A limitation of this study is the presence of self-selection bias in the interview process. The self-selection bias, where individuals who have a particular interest or expertise in the topic are more likely to participate, could skew the findings towards certain viewpoints, as opposed to a more random sampling of industry professionals [50]. This limitation was mitigated by the inclusion of diverse participants across the fields of rail, project management, and infrastructure advisory; future research could expand the participant pool to include a wider array of stakeholders to reduce bias.

3.4. Ensuring Validity of Primary Data

To ensure the reliability and impartiality of the primary data collected, specific controls will be implemented in both the selection of participants and the data analysis process. Interviewees will primarily be infrastructure experts from NSW, selected for their experience in delivering large-scale projects, particularly within the rail sector. The interview questions will be carefully crafted in accordance with the Marketing Scales Handbook by Bruner [47], minimising the potential for bias in responses.

Reliability and validity were further maintained by asking each interviewee the same core set of questions. This approach facilitated a consistent comparison and analysis of the data and encouraged open conversation [51].

Interviews are conducted individually, following ethics approval from the University of Sydney, using a semi-structured “controlled conversation” format. In instances where biases are detected during discussions, follow-up questions will be used to seek factual or experiential clarification, thus safeguarding the integrity of the data.

3.5. Data Analysis

A deductive approach will be used to analyse the interview data, meaning that key themes will be identified before the conversations take place [52]. After the interviews, the key points will be revisited and explored further through a comprehensive literature review. The findings will then be presented as recommendations on actions to take—or avoid—to support the implementation of HSR in Australia. NVivo software, version 14, is used to code the interview transcripts into themes established in the literature review. While efforts were made to ensure consistent coding, this study did not include an intercoder reliability test, which limits the ability to formally assess the objectivity and reproducibility of the thematic analysis. This is acknowledged as a methodological limitation and an opportunity for improvement in future research.

Survey data will also be used to support this analysis. The themes of the survey questions align with those in the interviews, allowing the survey results to reflect broader industry sentiment and reinforce the key themes identified in the interviews. The survey data are analysed using the AHP method.

AHP provides a systematic framework to quantify subjective judgments, which is essential for identifying key barriers to implementing HSR in Australia. This method allows survey participants to express their perceptions regarding several factors through pairwise comparisons.

• Pairwise Comparison: Used to evaluate the relative importance of different barriers, such as “funding challenges” and “regulatory hurdles”, using a scale from 1 to 9. This process captures nuanced opinions and facilitates a comprehensive understanding of each barrier’s significance [53];
• Numerical Representation: The pairwise comparisons are converted into priority weights, providing a clear quantitative measure of how each barrier is perceived relative to the others. For example, a higher weight for funding issues indicates greater concern among stakeholders;
• Synthesis of Results: AHP synthesises the results to generate a ranked list of barriers, enabling decision-makers to prioritise actions and strategies that address the most critical challenges to HSR implementation [54].

The above process is further explained in detail in the Results section. Control questions from the survey will be cross-referenced with existing literature to ensure the reliability of the data. This approach reflects the triangulation method, which strengthens the validity of the research by combining multiple data sources.

4. Results on Australian HSR Risks

4.1. Survey Results

4.1.1. Survey Overview

Fowler [55] notes that surveys should be open long enough to reach the target audience. However, they should not be left open for too long, as it introduces time-related biases in the research. Fowler’s publication found that the appropriate survey duration ranges from 3 to 8 weeks [55], thus supporting this research’s 7-week period.

Rapid changes characterise the Australian HSR domain due to continuous advancements in technology, evolving policies, and shifting public opinions. New information frequently comes to light, influencing stakeholder perspectives and the feasibility of such projects. Given this dynamic environment, a 3- to 8-week period proposed in Fowler’s research for conducting surveys is considered reasonable, further substantiated by a 7-week survey period requiring minimal resources.

While 44 responses may seem limited given the broad societal implications of high-speed rail (HSR), this study specifically targets professionals within the infrastructure and construction industry, as they are directly involved in the planning, design, and delivery of such projects. The aim was not to capture the views of all stakeholder groups, but to explore industry perspectives on barriers to HSR implementation. From a statistical standpoint, the sample size exceeds the threshold at which the Central Limit Theorem (CLT) applies, supporting the reliability of observed trends within this group [56]. However, the findings should be interpreted within this scope, and future research could expand to include perspectives from policymakers, economists, and the general public to enrich the analysis.

The demographic of the survey participants is shown in Figure 6 below. Nearly 40% of the respondents had over 21 years of industry experience, providing confidence in the insights gathered, reflecting the perspectives of seasoned professionals with extensive knowledge and expertise in the field. Most respondents had 0–5 years of industry experience, ensuring that the survey captures the mean sentiment from both ends and offers a well-rounded view of industry perspectives.

The participants in this survey have worked on megaprojects across various industry sectors, as shown in Figure 6. Notably, 33% of respondents have experience specifically in rail sector megaprojects. Given the relevance of their expertise in HSR projects, this lends further validity to the survey results.

4.1.2. Analysing Survey Data Using the AHP Method

The AHP method used in this research begins by assigning weightings to survey respondent attributes. The background questions include years of experience, field of work, and major project sector in which the participant has experience. Trivially, prioritisation is given to input from more experienced participants, particularly those involved in relevant project management of rail projects. However, this is also a notable limitation of the AHP method as those who are not as experienced could also provide valuable input. Nevertheless, the weightings given to responses from individuals with certain industry and work experience characteristics ensure that these subsets of individuals hold greater significance. Additional details on industry sectors and work experience roles are provided in

Table 1. Survey respondent characteristic multipliers.

Criteria	Options	Multiplier
Years of Experience (Y)	21+	0.558
	11–20	0.263
	6–10	0.122
	0–5	0.057
Field of Work (F)	Project Management	0.633
	Infrastructure Advisory	0.260
	Other	0.106
Major Projects Sector (P)	Rail	0.418
	Water	0.212
	Energy	0.110
	Commercial Buildings	0.067
	Industrial	0.110
	Other	0.067
	Empty	0.018

.

These weightings were then used to construct pairwise comparison matrices of respondent attributes, where the relative importance of different experience levels (e.g., 21+ years vs. 11–20 years) was compared. The comparisons were guided by expert judgement and structured using the standard AHP 9-point scale, where higher scores reflect greater relative importance. For example, participants with over 21 years of experience were considered significantly more influential than those with 11–20 years and were assigned a score of 7. Similarly, those with 11–20 years were rated 5 compared to respondents with 6–10 years, and so on. While these judgments were somewhat subjective, they followed a consistent logic based on perceived expertise and relevance. This process was repeated for each attribute: Years of Experience, Field of Work, and Major Projects Sector. The resulting matrices were used to calculate priority vectors (or multipliers) using the eigenvector method.

To calculate the final respondent weightings, each pairwise comparison matrix was normalised by dividing each element by the sum of its respective column. The average of each row in the normalised matrix was then computed to produce a priority weight for each respondent category, representing its relative importance. These weights were subsequently used to adjust the influence of each participant’s input in the broader analysis. Although the specific values were based on researcher discretion and are not empirically validated, the primary aim was to establish relative importance across groups. Table 1 presents the final respondent multipliers used to weight responses according to participant attributes.

The current weighting system introduces some mathematical inconsistencies. For instance, the weighting for participants with 6–10 years of experience is three times higher than those with 0–5 years. Similarly, the weighting for 11–20 years is three times higher than that for 6–10 years. However, the difference between 11 and 20 years and 0–5 years is fivefold, which creates an imbalance in proportional increases. This reflects the limitations of using expert-driven pairwise comparisons, which can be subjective. A more refined and consistent weighting approach is recommended for future research.

Survey responses were collected on a 1–5 Likert scale (1 = low sentiment, 5 = high sentiment). The raw data were exported into Excel for further processing. Each participant’s rating for a given question was multiplied by their respondent characteristic multiplier, as shown in Table 1. Then, a combined average was found. The process for answering any given question per respondent is illustrated in

Table 2. Sample survey response weighting example.

Item	Rating/Weighting
Respondent A Rating (Q)	4 (out of 5)
Years of Experience of Respondent A (Y) = 21+ years	0.558
Field of Work of Respondent A (F) = Project Management	0.633
Major Projects Sector of Respondent A (P) = Rail	0.418
$\mathrm{Weighted} \mathrm{Rating}=Q\times Y\times F\times P$	0.591

below.

This process ensured that responses were weighted according to expertise. After multiplying the raw ratings by the participant weightings, an overall average rating was calculated for each survey question.

The above questions were also organised into a pairwise comparison matrix to evaluate their relative importance. The matrix was normalised, and priority weights were again calculated by averaging the rows of the normalised matrix. A finalised list of weighted questions was obtained and ranked from highest (most important) to lowest (least important).

Table 3. Average weighted Likert scale rating for 5 random survey questions.

Survey Question	Average Rating
How likely is it that the construction of the HSR project will be delayed?	0.223
HSR projects require a greater-than-average risk contingency.	0.215
The high HSR development and construction cost is a barrier to its implementation in Australia.	0.213
How likely will the HSR project be delivered over budget (cost overrun)?	0.222
The implementation of HSR will benefit Australia by increasing land coverage.	0.174

presents the average weighted ratings for five randomly selected questions.

In AHP, pairwise comparisons are used to assess the relative importance of different criteria or alternatives. These comparisons are subjective, meaning there is a risk of judgement inconsistency. The Consistency Ratio (CR) is a measure used to check the logical consistency of these judgments and ensure that the overall decision-making process is reliable [53]. A CR of less than 10% indicates that the inconsistencies are tolerable [56], and in this research, it was well below this threshold.

Figure 7 presents the final list of barriers ranked on a scale from 0 to 1, where 0 represents the least essential barriers and 1 indicates the most important. To interpret the chart, focus on the rankings: for instance, “Transport Shift” received a weighting of 0.92, while “Carbon Reduction” received a weighting of 0.91. This means that the AHP analysis found that survey participants considered the impact of HSR on reducing car and plane trips (Transport Shift) to be slightly more important, placing it in the top 8th percentile, whereas carbon reduction ranked lower in the top 9th percentile. Although the difference in numerical weighting is minor, it suggests a subtle prioritisation of practical, mode-shifting outcomes over broader environmental benefits. This may reflect a view among stakeholders that encouraging behavioural change in transport usage is a more direct or actionable goal, whereas carbon reduction is perceived as a downstream effect rather than a primary driver in HSR decision-making.

The questions in the chart were given shorter labels for clarity. This analysis will be further discussed in the Discussion Section.

4.1.3. Limitations of the AHP Data Analysis Method

• Limited Criteria for Weightings: Only three experience-based criteria were used as weightings: experience, position, and sector. However, these may not necessarily correlate to the most meaningful insights, as higher experience or position does not always result in more relevant responses. For instance, someone with nine years of experience may offer more insightful responses than someone with eleven years, but the weighting will automatically favour the latter due to the multiplier;
• Subjectivity and Repeatability: Given the subjective nature of participants’ responses, AHP results are not fully repeatable [57]. While the overall findings would likely be similar, slight variations in individual judgments could alter the final rankings;
• Condorcet’s Paradox: Condorcet’s paradox can arise when aggregating group data in AHP, where individual preferences, even if rational, result in a cyclical or contradictory group preference. This paradox complicates identifying a majority preference and can obscure the prioritisation of criteria, creating challenges in forming a clear consensus on key barriers [58].

4.2. Interview Results

4.2.1. Interview Overview

In this research, nine interviews were conducted. This was supported by research published by Guest et al. This publication found that basic themes begin in as few as six interviews, and saturation of key themes occurs in as early as 12 interviews [59]. This suggests that 6–12 interviews are the most efficient in obtaining key themes. Hence, the nine interviews conducted in this research are deemed sufficient.

The interviewees were high-profile industry experts, as shown in

Table 4. List of interviewees.

Interviewee	Title
P1	C-Suite Executive, Rail Authority
P2	Executive, Rail Authority
P3	Infrastructure Financing Specialist
P4	Project Management Specialist, PhD in Project Management
P5	Politician, Transport Portfolio
P6	Former C-Suite Executive, Rail Authority
P7	Infrastructure Advisor
P8	Infrastructure Advisor
P9	Politician, Transport Portfolio

below. This list consists of an executive from every major railway agency in New South Wales.

4.2.2. Analysing Interview Data

The interviews were transcribed using AI with audio MP3 recordings from Zoom or voice memos. The transcript was uploaded into NVivo (version 14). This computer-assisted qualitative data analysis software (CAQDAS) is used to organise qualitative data into data themes, as realised in the literature review. Flick discusses various qualitative research methodologies and highlights how CAQDAS can enhance the rigour and efficiency of qualitative analysis, particularly in handling large volumes of interview data [60]. Quotes from interviews were gathered and coded into these themes using NVivo 14. The key data collected from all interviews are shown in Figure 8 below.

5. Discussion of the Australian HSR Risks

This section highlights the paper’s contributions to the theoretical understanding and practical advancement of HSR development in Australia, based on a review of relevant publications and lessons learnt from a case study investigation. The study’s primary research contribution is the systematic identification, qualitative exploration, and quantitative prioritisation of key barriers hindering HSR implementation within the Australian context, employing a mixed-methodology. This provides multiple distinct insights into why HSR projects have historically stalled post-feasibility.

Another primary contribution lies in identifying and listing reasons why mega-projects may have encountered significant time and cost overruns, and clarifying the severity of these challenges. This paper reveals that many rail and transport initiatives have faced these significant overruns, a finding reinforced by the AHP analysis, which ranked cost and time overruns as the first and second most critical barriers, respectively.

The next notable contribution is the exploration of construction risk transfer, where our study highlights a greater-than-average risk contingency as a top priority. Although this paper does not intend to generalise the findings, it presents some information on risk allocation strategies in the selected infrastructure project.

In addition, this work advances the discussion on the value of private sector expertise. This proposes methods to enhance private sector engagement and foster collaboration in infrastructure development, a critical step toward improving project outcomes. Finally, the paper presents a set of practical recommendations derived from these findings, or lessons learnt from the case study, which are intended to guide future HSR projects in mitigating identified risks and enhancing efficiency.

Collectively, these contributions provide both empirical evidence and actionable insights, making this study a valuable resource for stakeholders seeking to address persistent challenges in HSR projects. The empirical evidence is grounded in extensive secondary research and expert interviews. P1 emphasised the originality and significance of the research, describing it as “quite original” and “absolutely important”, and expressing his interest in reading it. P9 acknowledged the research as an “important project”, and P6 stated it “adds to [the] debate” around HSR and “enhances the credibility of [the] mega project”.

Section 5.1, Section 5.2, Section 5.3, Section 5.4 and Section 5.5 provide in-depth discussions on the identified barriers and recommendations, backed by interviews, AHP survey results, and extensive literature. These sections present discussions to support further discourse on HSR and enhance the research’s visibility in the field, fostering a more robust discussion on realising HSR in Australia. These contributions are discussed as follows:

Barriers to HSR Implementation in Australia

This section outlines the key barriers hindering HSR implementation in Australia. There is limited prior research summarising these barriers, so this analysis is crucial in addressing the research objectives. These themes align with the barriers identified in the literature review and are further validated through the data collected in this research.

5.1. The Benefits of Implementing HSR in Australia

There are arguments that Australia does not need an HSR network, primarily due to its population distribution and the potential limited impact. Many academic studies point to Australia’s relatively low population density along the proposed HSR routes, suggesting that only a few people will benefit from its implementation. However, P1 highlights that approximately 60% of Australia’s population lives on the East Coast. Over the next 25 years, Australia is set to grow in population by circa 30% [61]. P1 notes that while other regions, such as the UK, parts of Europe, and the US, are experiencing moderate population growth, and Japan is declining, Australia is on track for significant expansion. Given this trajectory, P1 emphasises that investing in HSR is ultimately a matter of strategic choice, as the country will inevitably need to accommodate a growing population and increasing urban congestion. This aligns with forecasts from the Australian Bureau of Statistics, which project continued population growth, reinforcing the potential value of HSR in easing pressure on major cities.

The interviews found that a choice to invest in HSR is believed to make Australia’s future prosperous. The survey results analysed by AHP also ranked a prosperous Australian future in the top 10 percentile, compared to the other themes in the survey. P9 Minister for Transport also agrees with this. In a letter directed towards this research, she mentioned HSR will be “delivering more job and lifestyle choices, greater housing options and new economic opportunities”. These benefits are also supported by P1 and the literature review conducted in [3].

In the context of the Sydney to Newcastle corridor, several interviewees, including P3, P1, P4, and P2, support the concept of “Newcastle 2.0”. They argue that HSR could transform Newcastle into a hub by enhancing connectivity and unlocking land value along the corridor. P2 further emphasised that the primary beneficiaries of HSR would not necessarily be those living in Sydney or Newcastle but rather surrounding area residents. Those in regions such as Gosford, Goulburn, and Albury-Wodonga would gain improved access to economic opportunities and essential services through enhanced transport connections, making HSR a catalyst for regional development.

Interestingly, the survey ranked both personal and community impacts low, around 0.6, indicating only a 60% significance compared to other key ideas. This suggests that participants, many of whom reside in metropolitan Sydney, do not perceive significant personal benefits from HSR, aligning with P2’s statement that the broader region can gain more.

Sydney trains are widely described at an unreliable mode of transport due to the frequent signalling and union issues. P1 attests and describes our current Sydney train systems as “slow” and “unreliable”. He claimed that patrons would, as a result, experience a big and noticeable difference. These would come in the form of reliability and time-saving. A notion was also attested by authors Gu and Li [62], who noted China’s extensive HSR network as reliable through an evaluation index and a great influence on the local community. This has also been widely accepted by other authors, particularly Nash, who wrote about HSR’s dependable operational reliability compared to air and road travel [24,63]. Authors like Givoni [64] also commend HSR’s reliability compared to even regional rail, as attested in this research’s interviews. P8 reinforced this notion, emphasising that reliability and time savings are among the most tangible benefits of HSR.

Sustainability is another critical factor. Australia’s East Coast is primarily serviced by air travel [65]. HSR could significantly reduce emissions by providing a greener alternative, as noted by P2, P8, and P1. This shift would contribute to reducing Scope 1 and Scope 2 emissions. P2 emphasised that such a transition would have a substantial impact, potentially making one of Australia’s most significant reductions in carbon emissions from the airline industry.

Hence, the benefits of HSR in Australia are significant. The primary data aligns with the theory established in the literature review. This shift would transform conventional practices like fly-in–fly-out and drive-in–drive-out to a streamlined and comfortable train-in-train-out commuting system. This transition could significantly impact workforce mobility and regional development.

The literature review found that the Sydney to Newcastle HSR alignment would have a worse BCR than the Sydney to Melbourne alignment. It found this to be a significant risk. However, the interviews showed that this held true only if HSR were to be considered a transport project. P1, P2, P4, and P3, all of whom positioned HSR as a Regional Economic Development (RED) project rather than just a transportation initiative. P1 mentioned that in this feasibility report, the HSRA is pivoting from thinking about travel time and comparisons with airlines and “think about what it actually does for the regional economy”. P4 further attested to that saying, think of “it being an economic development project”. This important benefit needs to be captured in HSRA’s upcoming feasibility study to ensure approval, as this would capture the RED benefits. Ensuring HSRA’s feasibility study positions this alignment as a viable option for HSR in Australia is important. P2 further supported this approach, stressing that positioning HSR as an economic development initiative is essential to its success.

The word cloud analysis, as shown in Figure 9, presents interviewees discussing the benefits of high-speed rail and reveals key themes and priorities emphasised by the interviewees. The most frequently mentioned words, displayed in larger font sizes, such as “people”, “high”, “speed”, “rail”, “land”, “Sydney”, and “Newcastle” stand out. However, these were expected as the interviews specifically focused on the Sydney to Newcastle alignment. Additionally, words like “construct”, “corridor”, “cities”, “connect”, “plan”, “opportunities”, and “emissions” reflect the broader considerations of infrastructure development, economic opportunities, and environmental benefits. They highlight the significance of connectivity, speed, and impact on people and land, and the importance of linking major cities and regions. This visualisation offers a clear and immediate understanding of the main themes and priorities identified by the interviewees regarding high-speed rail.

5.2. Concept Phase Risks Preventing Realisation

The literature review identified many risks preventing the realisation of HSR in general. Most of these risks presented were those in the concept phase of the project life cycle. This is before the project is being delivered, and risks that prevent the project’s approval. This section of the research presents an array of these concept phase risks that prevent the realisation of HSR in the Australian context, with the predominant risk being the risk of cost and time blowouts.

The word cloud analysis of the interviews, shown in Figure 10, highlights several key themes and concerns related to high-speed rail projects. Prominent terms such as “people”, “government”, “project”, “cost”, “risk”, “place”, and “challenging” stand out, indicating the central issues discussed by the interviewees. This visualisation underscores the importance of addressing costs and time management, construction risks, political risks, and market readiness. The insights gained from this analysis serve as a foundation for a deeper exploration of these critical subtopics.

5.2.1. Cost and Time Estimates

The literature review presented a list of Australian mega projects that experienced time and cost blowouts. This highlights the severity of this issue, with many rail and transport projects experiencing severe cost and time blowouts in the magnitude of billions. The AHP analysis in this research also confirmed this, with cost and time overruns ranking 1st and 2nd, respectively. Further, the survey participants also ranked the inflated cost of HSR development and construction in the top 4th percentile. This makes it an important barrier to its implementation.

The first step towards ensuring no cost and time blowouts is to ensure that the initial budget and time estimates are accurate. P4 agreed and argued the most significant risk is having an accurate budget forecast. P4 raises the initial error project leaders make is creating a project that fits into a predetermined budget—“Well, I can only approve $3 billion, right? Well, that’s how much it’s gonna cost”. This happens partly because of external or political factors discussed in Section 5.2.3. Fitting a project into a predetermined budget might help get it approved. However, due to a lack of budget confidence, treasuries are growingly challenging to commit to new mega projects. This may justify why it is important to model the budget appropriately. P2, P1, and P4 all reference the author Bent Flyvberg [14,26,30], who was deemed an expert in the mega project governance domain and was referenced multiple times in the literature review. They refer to the Theory of Reference Class Forecasting (RCF) [30,66], which says to check what the budget has been for similar past projects to reduce optimism bias and strategic misrepresentation in estimates. As identified in the literature review, range-based estimates were suggested by many authors [2,14,67]. P1 is very much in agreement with this idea for his upcoming Sydney to Newcastle HSR business case.

P1 mentioned that in the case of the HSRA business case for the Sydney to Newcastle alignment, they planned to “get cost planners to build up a bottom-up estimate… based on a 10% design”. P1 also briefly visited the idea of RCF theory by taking the cost estimate and deducing “how much is it per kilometre? And how does that compare to the industry benchmark”? The RCF theory backs the triangulation method highlighted, and it compares the Australian HSR project with other HSR projects around the globe, as shown in Figure 11 below. P1 hoped the Australian HSR project would appear next to Spain in the chart shown in Figure 11 below.

P1 emphasised the importance of “working through and getting the scope” right, explaining that “the more defined the scope is, the more likely you are to estimate the price” accurately. During the interview, P2 shared a relevant example from the UK’s Crossrail project: “Three years into Crossrail, they started facing budget challenges, and the team immediately considered cutting scope instead of looking at how to mitigate risks more aggressively”. This highlights the need to prioritise risk mitigation rather than reducing project scope when costs escalate. As P2 put it, “the key is, first, getting the scope right”. The literature review highlighted how changes in project scope can lead to cost increases, a finding further confirmed by interview insights.

Another important way to ensure that the project stays within the budget and time estimates is to really focus on supply chain management. Particular focus on important materials like concrete and steel needed for construction is key, as highlighted by P1 and P2. This was another key learning in the literature [14] which emphasises the importance of managing the supply chain effectively to avoid delays and cost overruns in megaprojects. P1 points out that a well-coordinated supply chain can mitigate risks related to procurement, logistics, and price fluctuations. P2 attests and recounts an anecdote from his rail project where he said the following:

“strategic supply chain management… we’re doing a lot, but as you know, we’re not the only game in town. We have basically locked up the entire market on concrete”.

P1 also agrees, denoting that

“if you have too much work at one time, then resources get down, prices go up, and your project goes up”.

This will drive the prices up for the HSR project and restrict the trade of other businesses, which ultimately affects the HSR project as well because of the sheer volume of downstream contracts required to deliver a megaproject of this calibre. So, good supply chain management is an important consideration, as poor supply chain coordination often leads to cost escalations and delays, according to Merrow [69].

P3 emphasised the importance of factoring in the statutory land acquisition process, which typically lasts 18 months.

“At least an 18-month statutory period to try and go through it. So, by the time you’re awarding contracts, you’ve bought all the properties you can, and you’re generally in the Land and Environment Court with the larger landowners—the ones who will hire armies of lawyers to challenge your valuations”, noted by P2.

This process can be highly unpredictable, with P1 adding, “These are quite volatile things”.

To support this, academic literature highlights the complexities of land acquisition timelines in large infrastructure projects. Studies have documented significant delays due to legal challenges and negotiations, underscoring the unpredictability of this phase. This was further exacerbated in the Infrastructure Priority List [70], where Infrastructure Australia noted that land acquisition is one of the major sources of cost blowouts and delays in megaprojects. They emphasise that securing land is often subject to lengthy negotiations, legal disputes, and rising property values, which makes it both expensive and time-consuming [70].

5.2.2. Construction Risks Transfer

Mega projects are also mega in risk, so planning to manage and mitigate risks from the inception of the project is vital to its success. “These mega projects have huge, huge risks” says P5.

As noted in the literature review, risk allocation is one of the most critical factors for managing large-scale projects. This is also seconded by this P2, who recommends “find out what risk allocation is viable”. Flyvbjerg, the leading scholar on megaprojects, recommends a 50–60% risk contingency to cover potential cost blowouts. This is echoed by P2, who anecdotally shared,

“I had a conversation with a counterpart in Victoria several years ago now, and his assessment was whatever the cost estimate is, you need 60% of that in contingency. That’s an ungodly number that no treasury would ever invest in. But you have a look historically and a lot of like Flyvberg’s insights, and yes, 60% is probably not bad”.

The survey participants in this research also identified a greater-than-average risk contingency as a top priority, a conclusion supported by the AHP analysis. This ranked in the top 3 percentile amongst the other questions. P4 agrees, adding, “In the UK now, they’ve realised that typically the contingencies are 50%, not 5%”. This highlights the widespread understanding of needing larger contingencies for complex projects [71]. P1, however opposes this idea, stating, “I don’t think 60% is the right answer”, claiming that you would never build anything otherwise.

P2 further explains that the challenge is that no project would move forward with a 60% risk contingency, as it is far too large for approval. Instead of a fixed percentage, P1 advocates for a probabilistic approach to risk estimation. A lower contingency is appropriate for more predictable greenfield projects, whereas brownfield projects—especially tunnelling—may require up to 100% contingency due to their “surprise package” nature.

“If we look at New South Wales rail projects in general, and Victorian ones and Queensland ones, they consume, anecdotally, I would say, at least a third of their contingency by the time they get through tunnelling”, P2 observes.

The issue of risk allocation between the government and contractors is further exacerbated by the onerous contracts imposed on contractors.

“The government’s passing a significant amount of risk to the contractors, and the contractors are having to swallow that risk”, says P4.

“Contracts are too onerous”. Furthermore, as P2 points out, “Government by de facto takes on, takes back risk it has contracted out”, because “it’s not like government can sue itself”.

An example of this dynamic is the Sydney Light Rail project, where Acciona sued the NSW government for $1.1 billion due to misleading or deceptive conduct related to unmapped utilities under George Street. The contract did not account for such unknown risks, and the government ultimately bore the responsibility [33].

“Oftentimes, in a lot of cases like [utilities], they don’t have sophisticated BIM models for their entire network. And so inevitably, you start on a bit of a back foot because you go to market for your tunnelling packages and government, the client, ends up on risk for so much because the tunnelling contracts, like, you give us a guarantee that this is all the utilities and you can’t“, explains P2.

He further notes the additional complications surrounding heritage and archaeological concerns. “For heritage, for archaeological, we’ve got really wonderful but stringent rules around heritage finds, both European and Indigenous. And so, tunnelling contractors are just like, you’ve given me the crappiest, you know, bit of Geotech investigations. We’ve got no idea where the utilities are. Government, you’re 100% on risk”.

These examples highlight the complexity of managing risk in Australian megaprojects, especially when it comes to the unknown factors that arise during construction.

5.2.3. Political Risk

Flyvbjerg highlights how political agendas often influence megaprojects, resulting in cost overruns and delays due to shifting priorities and scope adjustments driven by political interests [14]. In the Australian context, the development of HSR is no exception. P8 mentions the pressure of political timelines, noting that “we’re never more than a year or so away from an election, state or federal, somewhere along the line. And so there’s always going to be somebody who doesn’t like it”.

This demonstrates how political cycles continuously affect long-term project decision-making. P2 further mentions how a coincidentally large number of projects are aligned with political cycles.

P2 further elaborates, stating, “so there’s this fixation that basically you, for major projects, you give yourself 4, 8, 12 years to do it”.

This political fixation on deadlines often leads to overly ambitious promises, contributing to the frequent issue of projects running over time and over budget due to politically driven agendas rather than realistic planning.

Siemiatycki’s [72] work supports this perspective, highlighting that political pressures frequently result in ambitious timelines and budgets for infrastructure projects, often leading to inflated expectations and eventual overruns.

A report by Infrastructure Australia, Infrastructure Decision-making: Political Influence and Project Outcomes [73], also outlines the strong influence of political decision-making on infrastructure projects. The report explains how political interests often dictate project selection, funding, and timelines, with political cycles frequently causing scope changes and shifting priorities, impacting long-term infrastructure planning.

P6 noted that, whilst a “good project management process is about an excellent benefit–cost ratio”, the political process is vastly different and relies on marginal seat analysis. Marginal seat analysis plays a key role in approving or rejecting HSR in Australia due to the political influence on infrastructure decisions. Governments prioritise projects that benefit marginal seats, as winning votes in these electorates is crucial for election outcomes. If the HSR route does not significantly impact these seats, there might be less political incentive to approve it. Conversely, politicians may push harder for the project’s approval if it does benefit such areas.

Local interests often outweigh national priorities, with representatives of marginal seats opposing projects that do not directly benefit their constituents. Additionally, since election cycles (every 4 years) drive project timelines, large-scale infrastructure like HSR, which has long-term benefits but few immediate outcomes, might face political resistance due to its lack of short-term visibility. This focus on electoral timing can delay or hinder HSR approval, especially if marginal seat voters perceive more immediate local needs. P6 mentioned that the political process is about marginal seat analysis.

However, P6 also noted that

“relying on the marginal seat analysis of politicians is a very unstable way to plan a project because with 3 and 4 year terms of governments, unless the project’s sustainable in its own right, the marginal seat analysis is very transient and can change very quickly”.

These political challenges reflect deeper structural issues. For example, institutional analysis helps contextualise how fragmented governance structures and federal-state misalignment can undermine long-term infrastructure planning and risk allocation. This is reflected in P3’s observation that the federal government may be “exceedingly reluctant to commit $70 billion for a high-speed rail to connect between Sydney and Newcastle”, as it spans only one state. Conversely, P1 counters that HSR should be seen as benefiting the national economy, regardless of geography.

Additionally, elements of path dependency theory help explain the persistent policy inertia and bias toward road and aviation infrastructure. Although this study does not formally adopt a theoretical framework, these perspectives offer useful interpretive lenses. Future research could explore hypotheses such as: “Federal-state misalignment is positively associated with higher contingency allowances in large-scale transport infrastructure projects”.

While this research adopts a qualitative and exploratory approach, the findings suggest a strong potential for modelling policy risk transmission in a more formalised way. For example, election cycle pressures, marginal seat sensitivity, and jurisdictional misalignment could be treated as dynamic inputs affecting project continuity, approval timing, and cost escalation. Future studies may explore this through mathematical modelling techniques, such as differential equations or system dynamics, to quantify how political volatility propagates through infrastructure planning processes. This could enable more predictive insights into the conditions under which HSR projects are delayed or derailed due to policy instability.

In the survey conducted for this research, participants from metropolitan Sydney ranked local community benefits low, placing them in the 30th percentile. This lends credibility to P3’s concerns about the federal government’s hesitance to invest in projects that may only benefit certain regions. Despite these political challenges, P5 offers optimism, stating that, politically, HSR is “a no brainer”. The government must respond to public demand, meaning that strong public support for HSR could drive political will to invest in it. Addressing stakeholder concerns and building public support will be essential in advancing such megaprojects.

5.3. Going to Market

Private sector expertise is vital in the delivery of HSR in Australia. As previously mentioned, the literature lacks a clear framework for effectively engaging the private sector. Much of the decision-making in going to market appears to rely on the experience of individuals with decision-making authority. Hence, it is imperative to identify and present the factors to consider when entering the market. P6 highlighted that when going to market, “market competition is criteria number 1”. The Infrastructure Australia report on “Infrastructure Decision-making Principles” supports this idea and stresses the importance of a competitive marketplace to ensure optimal cost and quality outcomes for public infrastructure projects. It provides insights into how market competition is essential for balancing demand and achieving efficient project delivery, especially in large-scale public works such as HSR [73]. P5, however, worryingly highlights the difficulty of securing private industry involvement due to the high costs of the Australian HSR project.

Private sector involvement in Australian infrastructure, particularly in the transport sector, appears to be waning amid heightened economic and operational pressures. This shift is highlighted by declining investor interest in transport assets, as many investors are turning towards renewable energy and other less-risky, higher-yield areas. The 2023 Australian Infrastructure Investment Report found that transport asset classes now face record-low interest from private investors, a marked contrast to the country’s high demand for renewable energy investments [74].

To encourage greater private sector engagement, fostering a collaborative environment between clients and contractors is crucial. For example, in the case of the Australian HSR project, P2 highlights the benefits of an Early Tender Involvement (ETI) approach. The private sector can review, critique, and provide feedback on specifications by sharing draft tender documents before their official release. For instance, P2 recalls implementing this method on their rail project, allowing contractors to pinpoint unclear risk areas and potential reluctance to assume risk. Addressing these issues early enables more effective risk management by either retaining specific risks or creating incentives for private sector involvement. This approach refines tender specifications and increases private sector enthusiasm, aligning interests for smoother project execution. The literature views this idea as shown in Figure 12 below.

P2 discusses the experience with their rail project:

“For each of our stations, we went out with an 800-requirement specification. It was massive, with a 6-star Green Star rating, and it was very extensive. Naturally, the price came back horrifically expensive”.

He notes that the lesson learned from going to market is clear: a lengthy list of requirements will result in a significant price tag.

For the P2’s rail project, they explain,

“What we’re trying to do is say we want a safe, functional, high-frequency railway. Please price that, and then talk to us about a two-story development. Give us an option for a six-station development, and then provide your highest and best use offer”.

By approaching it this way, he believes the private sector can be encouraged to innovate, leading to a minimum viable scope that is the most affordable option. It will also provide the best land use option, which will naturally be more expensive. This aligns with the MoSCoW framework for defining the minimum viable scope.

The MoSCoW framework is a project management method used to prioritise requirements based on their importance. The acronym stands for the following:

• Essential requirements must be met that are non-negotiable for the project’s success;
• Should have: Key features that are not critical; they can be deferred if necessary;
• Could have: Desirable features that can be included if time and resources permit;
• Won’t have: Features that will not be implemented in the current project phase due to constraints or strategic decisions.

This framework helps teams focus on delivering the most critical elements first, effectively managing scope and expectations throughout the project lifecycle [75]. The literature supports P2’s suggestion and supports his idea that presenting these options allows for negotiation with the government.

However, P2 also acknowledges the costs involved for the private sector in the tendering process: “It costs money for the private sector to make bids; I don’t diminish that”. He proposes longer tender periods, allowing the private sector to allocate a team for 24 months, fostering collaboration and minimising losses even if they do not win the tender. He suggests a 75% bid cost reimbursement for the intellectual property developed, regardless of whether they secure the tender. This proposal is a novel idea in Australia and has not yet been widely adopted. Secondary data show reasons for and against this, as shown in Figure 13 below. Ultimately, the idea raised by P2 has merit and reflects ongoing discussions in procurement practices, especially in complex projects. Implementing such changes may require careful consideration of the balance between encouraging participation and maintaining competitive, efficient procurement processes. This approach would lead to a more defined scope, with requirements presented by the private sector, enhancing cost estimate confidence as the scope becomes more developed.

P1 stresses the importance of “working through and getting the scope right” because “the more defined the scope is, the more likely you are to estimate the price correctly”. He advocates involving contractors in the design process, as they are the ones who will execute the construction. “We’ll end up with people who want to build it, designing it”, he states.

In contrast, P4 recalls, “Back in the old days, [the government] used to manage the design. You’d work out what you wanted, get it all designed up, and then get the contractors to price it”. This reflects a design-and-construct (D&C) approach (rather than a build-only model), which can yield efficiencies by integrating design and construction processes. However, P4 highlights a notable limitation: “You’ve got to have four designers for every project—one on the client side and three on the tenderers’ sides”. As P1 and the literature noted, a skills shortage is a high implementation risk. A lack of local talent would necessitate the attraction of international talent, which presents an additional barrier to implementation in Australia. Hence, there is a need to address the long-term skills shortage. A conversation with P1 suggested the following workforce upskilling model, as illustrated in Figure 14 below.

Australia has not yet undertaken a specialised project requiring extensive workforce upskilling. Concerns about a lack of expertise are valid, as the country has no HSR experience. Therefore, this framework is considered novel.

5.4. Risk Matrix

As discussed above, the implementation of HSR faces numerous risks. These are summarised in the risk matrix in

Table 5. Risk matrix.

Risk Category	Risk Description	Likelihood	Impact	Risk Level	Mitigation Strategy
Cost and Time Overruns	Budget blowouts due to inaccurate forecasting, delays in land acquisition, procurement, and approvals.	High	High	Critical	Use Reference Class Forecasting (RCF) to compare similar projects; employ range-based budgeting instead of fixed estimates; ensure early land acquisition before central contracts.
Construction Risks	Unforeseen site conditions, tunnelling challenges, heritage site issues, and supply chain disruptions.	Medium-High	High	Major	Conduct detailed geotechnical investigations before work begins; implement Early Contractor Involvement (ECI) to detect risks early; establish supplier agreements for critical materials.
Political Risks	Change in government priorities leading to funding withdrawal or policy shifts.	High	High	Critical	Secure bipartisan support and frame HSR as a Regional Economic Development (RED) initiative instead of a transport project; ensure public engagement to create political pressure for continuity.
Market Readiness	Lack of private sector interest due to high capital costs and long project timelines.	Medium	High	Major	Break down projects into smaller work packages to reduce financial barriers; offer incentives like risk-sharing models; explore international expertise via global tenders.
Risk Allocation	Contractors refuse to take on excessive risk, leading to disputes and claims.	Medium-High	Medium	Major	Use alliancing contracts or Public–Private Partnerships (PPP) with risk-sharing mechanisms; ensure early risk workshops with contractors.
Feasibility Perception	Public and political scepticism is due to the perceived low benefit–cost ratio (BCR).	High	Medium	Major	Reframe HSR as an economic development initiative rather than a transport project; highlight regional housing benefits and reduced congestion costs in feasibility studies.
Workforce Capacity	Limited domestic expertise in HSR design and construction.	Medium	Medium	Moderate	Develop HSR-specific training programmes in collaboration with universities and TAFEs; implement a staged knowledge transfer from international experts; integrate HSR training into existing rail projects.

.

Risk assessment in this study involves categorising each identified risk based on its likelihood and impact, drawing from the basic concepts of risk management. Likelihood is classified into three categories: ‘high’, indicating an event almost certain to occur; ‘medium’, suggesting a possibility based on the existing control measures; and ‘low’, denoting an unlikely occurrence. Similarly, impact is categorised into three levels: ‘high’, reflecting significant financial loss, project delays, or reputational damage; ‘medium’, indicating manageable disruption that requires intervention; and ‘low’, representing minimal disruption. The overall risk level is then determined by combining likelihood and impact, resulting in three classifications: ‘critical’, necessitating immediate mitigation; ‘major’, requiring proactive management to prevent escalation; and ‘moderate’, warranting regular monitoring to ensure containment.

5.5. Summary of Recommendations

The following recommendations are based on the findings from the previous sections. They are presented using a research-based recommendation structure as outlined by Creswell and Creswell [43]. These objectives are presented in an industry-ready manner, making them easy for professionals delivering nation-shaping projects of this nature to understand.

Recommendation 1: Position the Australian HSR Project as a Regional Economic Development (RED) Opportunity

• Justification: As presented in Section 5.1, previous HSR feasibility studies in Australia have struggled due to a failure to capture the benefits of regional economic development adequately. The analysis presented in this research highlights the significant advantages that a Sydney to Newcastle HSR alignment could bring to the residents of New South Wales and the broader economy;
• Industry Implications: The forthcoming feasibility study by the HSRA should emphasise these RED benefits, framing the project primarily as an economic development initiative rather than merely a transportation project. Clearly communicating these benefits is essential for garnering support and ensuring the study’s success.

Recommendation 2: Estimate Delivery Costs and Timelines Accurately for the HSR Project

• Justification: As presented in Section 5.2.1, mega projects in Australia often experience significant cost and time overruns, resulting in low confidence in budget forecasts. Accurate cost and time estimations are vital barriers to overcoming project realisation;
• Industry Implications: The HSRA should adopt Reference class forecasting to provide more reliable budget and timeline estimates, presenting these as ranges rather than absolutes. Maintaining a fixed scope after project commencement is crucial to avoid unnecessary changes that could inflate costs and extend timelines. Effective supply chain management is also crucial for mitigating cost fluctuations in raw materials.

Recommendation 3: Address Unknown Political Barriers

• Justification: As presented in Section 5.2.3, political factors are crucial in project approval, especially for public sector projects. The findings indicate that securing political buy-in is essential for advancing the HSR project;
• Industry Implications: The project must align with the political timelines of government cycles, typically 4, 8, or 12 years. It is advisable to overestimate required timelines to create a buffer for project execution, increasing the likelihood of success. Engaging with the public to foster support can also enhance governmental commitment, as investing in HSR is driven by national choice.

Recommendation 4: Foster Collaborative Engagement with the Private Sector

• Justification: As presented in Section 5.3, the government lacks the necessary expertise to deliver the HSR project, making private-sector collaboration crucial for its successful implementation. Engaging the private sector can enhance competition and excitement around the project;
• Industry Implications: The HSRA report should consider an Early Tender Involvement (ETI) process, which would allow private sector input in the design requirements for the HSR alignment tender. This collaboration can lead to more competitive bids and better project outcomes. Additionally, a tender reimbursement model could incentivize firms to invest time in detailed tender submissions, fostering innovation and efficiency. Furthermore, a detailed tender will likely provide a more accurate estimate of the actual cost and time.

Recommendation 5: Develop a Framework to Upskill the Australian Workforce

• Justification: As presented in Section 5.3, Australia currently lacks the necessary expertise to design and implement an HSR alignment, with the Sydney to Newcastle route being particularly complex. Upskilling the workforce is essential for successfully delivering this project and future HSR initiatives;
• Industry Implications: The business case must outline a sustainable approach to workforce development, ensuring Australia can competently deliver HSR projects in the long term. This research provides a potential framework for effectively upskilling engineers, as illustrated in Figure 14.

6. Conclusions

This study provided a comprehensive understanding of the early-stage risks to HSR implementation by fulfilling its core research objective: the identification and prioritisation of these risks. This was achieved by employing a rigorous mixed-methods approach, uniquely triangulating findings from the literature, expert insights, and stakeholder perspectives. The study explores the barriers specific to HSR implementation in Australia—an area with limited to no existing publications available publicly. While a wealth of studies examines general challenges faced by mega projects, including those encountered in HSR implementation globally, most Australian mega projects still proceed despite similar challenges. This suggests that unique, undocumented factors may be hindering the progress of HSR in Australia specifically, prompting the hypothesis that barriers beyond typical project challenges exist and must be identified.

The primary aim of this research was to uncover these barriers and propose practical recommendations to facilitate the successful development of HSR in Australia. This publication identified five major risks in the early stages of HSR conception: improper project positioning as a mere transport project, incorrect delivery cost and time estimates, unidentified political barriers, lack of substantial private sector collaboration, and no consideration of national workforce upskilling. These pose barriers to approval.

In fulfilling these objectives, this research makes a significant contribution to the field by identifying and providing industry-applicable recommendations to mitigate these risks. This publication analyses the distinct factors that have prevented the realisation of HSR in Australia thus far, offering a foundational reference for future researchers and policymakers aiming to progress HSR projects in the region.

This paper presents a novel contribution to the HSR implementation by systematically documenting and analysing non-technical political, economic, and risk-based barriers that hinder project approval. This addresses a critical gap in the literature, where technical feasibility is well established globally, but context-specific challenges, considering local conditions that affect project time and cost, remain partially underexplored. Its originality lies in several key advancements: First, it offers a timely analysis, aligning with the impending launch of the HSRA and ongoing HSR discussions, providing current insights into implementation obstacles. Second, it identifies and examines critical barriers, such as risk, financial constraints, and private-sector engagement. Third, it draws on practical insights from high-level interviews with influential figures in transport, government, and infrastructure, which may support theoretical frameworks with real-world perspectives. Fourth, it examines construction risk management, emphasising the importance of addressing higher-than-average risk contingencies and proposing strategies to promote private sector involvement and collaboration in infrastructure projects. Finally, the research delivers actionable recommendations derived from these findings, offering practical guidance to mitigate barriers and enhance the feasibility of future HSR initiatives. These contributions provide a unique blend of empirical evidence and strategic insights, advancing the field and supporting policy and planning efforts for HSR development in Australia. While this study is primarily exploratory and applied, it introduces theoretical lenses to interpret the findings, particularly through institutional analysis and path dependency theory. These frameworks help explain how governance fragmentation, short political cycles, and entrenched infrastructure preferences have uniquely constrained HSR development in Australia. In addition, Flyvbjerg’s concepts of megaproject risk, strategic misrepresentation, and political influence were used as a foundational lens to contextualise decision-making challenges. Any differences highlighted—such as the influence of marginal seat politics or federal-state fragmentation—are intended to reflect the specificities of the Australian policy environment rather than amend or challenge Flyvbjerg’s broader theory. Although a formal mathematical model of policy risk transmission was beyond the scope of this study, future research could explore this by applying system dynamics or differential equations to quantify how political instability, jurisdictional misalignment, or strategic uncertainty affect approval delays and cost contingencies in megaprojects like HSR. This direction could build on the current study’s qualitative insights with predictive capabilities, strengthening planning and evaluation for future high-speed rail initiatives.

This research bridges a significant gap in the literature on HSR implementation, considering the context-based situation in a selected city in Australia through extensive primary research and discussion to yield valuable insights. However, several limitations emerged, accompanied by suggestions for future studies. Like many survey-based studies, the sample size cannot be easily generalised, and it is predominantly from Sydney-based professionals. This may potentially introduce optimism bias; broadening geographic and professional diversity could strengthen future analyses. Optional survey questions led to incomplete datasets, suggesting mandatory responses or structured follow-ups in subsequent work. The AHP relied on subjective weightings based on participant experience, indicating a need to explore alternative methods to assess their impact on results. While interviews included seasoned senior professionals, their uniformity in experience—coupled with P1’s observation that “different ages see things differently”—highlights the value of including younger or less experienced voices for diverse perspectives. The interview sequence, dictated by availability, restricted follow-up across participants, pointing to the potential of a more iterative approach in future studies. Finally, the high-level nature of the collected data, with some insights only briefly addressed or excluded, suggests that narrowing the focus in future research could enable deeper exploration of specific barriers.