The Dutch Multi-Year Programme for Infrastructure, Spatial Planning and Transport (MIRT) is the central framework through which major infrastructure investments in the Netherlands are developed and coordinated. Although its phased decision-making structure is intended to progressively reduce uncertainty and guide feasible projects towards realisation, numerous MIRT projects experience delay, pausing or prolonged stagnation. Existing research identifies multiple explanations for infrastructure-project underperformance, including political pressure, optimism bias, multi-actor governance and resource scarcity, but these mechanisms are often studied separately. Less is known about how they interact within a formal phase-gate framework such as MIRT and how the practical operation of that framework shapes project trajectories.

This thesis investigates the factors and mechanisms contributing to delay, pausing and stagnation within MIRT and examines how vulnerabilities in the decision-making process may be reduced. A qualitative explanatory research design was adopted, combining a literature review, document analysis, semi-structured interviews and comparative case analysis. Three contrasting project trajectories were examined: the Lelylijn, Vlietlijn and A2 Deil–Vught.

The findings show that project stagnation cannot be attributed to a single bottleneck. Instead, it emerges from interactions between political pressure, project complexity, multi-actor governance, programme-level scarcity and time. Importantly, the findings do not indicate that the formal MIRT framework is fundamentally flawed. Rather, vulnerabilities arise in its practical application. Relatively easy project entry, weak gatekeeping and difficult no-go decisions can allow unresolved assumptions and political commitments to persist across successive phases.

The study further shows that programme-level scarcity is not solely an external constraint but can become self-reinforcing. Political prioritisation of new ambitions, postponed maintenance and renewal, optimistic project assumptions and the continued retention of projects collectively increase pressure on limited resources. Projects may consequently enter a grey zone in which they remain politically and administratively active without a credible route towards realisation.

The thesis therefore concludes that MIRT does not require fundamental redesign, but stronger institutional discipline. More selective entry, consequential gate reviews, clearer pause and exit conditions, stronger long-term portfolio prioritisation and well-defined governance arrangements can improve the ability of MIRT to guide feasible and strategically important infrastructure projects towards realisation. ... Read more

Generative AI tools such as ChatGPT are increasingly embedded in travel planning, yet how they shape tourist decision-making remains poorly understood. Existing research describes what generative AI recommends but not how travelers respond to it, leaving destination selection, sustainability perception, and transport planning largely unexamined as domains of AI influence.
This study's objective was to determine how interaction with AI-generated information and recommendations in travel-planning influences tourist decision-making. This question was examined across three domains of travel planning: destination preference, sustainability perception and behavioral intention, and transport choice.
To address this objective, the study employed an explanatory sequential mixed-methods design comprising three within-subjects experiments with 41 participants. Phase 1 examined destination preference shifts following open-ended ChatGPT interaction. Phase 2 investigated whether an AI-generated sustainability evaluation shifted travelers' sustainability perceptions and behavioral intentions. Phase 3 examined how AI-generated mobility advice shaped awareness and consideration of transport alternatives, as well as intended transport choice. Pre-post quantitative measures were combined with inductive content analysis of participant interviews to uncover the reasoning behind observed shifts.
Across all three phases, AI-generated advice shifted preferences and perceptions far more readily than it shifted intended behavior. In Phase 1, 88% of participants updated their destination preferences following AI interaction, resulting in choices that were, on average, less sustainable and skewed toward a recurring set of niche destinations. In Phase 2, AI-generated sustainability assessments significantly increased participants' perceived sustainability of a past trip, yet 68% indicated no intention to change their behavior on a repeat trip, with interviews pointing to validation-driven perception change. In Phase 3, only 30% of participants altered their intended transport plan after receiving AI mobility advice, though the majority reported learning new options and increased willingness to consider alternatives for future trips. Across all three phases, stated distrust of AI did not reliably predict resistance to its influence, and willingness and intent to use AI for future travel planning increased regardless of shifts to intended decisions. Participants consistently treated AI as a support tool rather than a final decision-maker, incorporating its output selectively into decisions they retained ownership over.
This study concludes that AI's influence on tourist decision-making is real but uneven across travel planning domains. It reliably reshapes what travelers prefer, perceive, are aware of, and are willing to consider, without requiring trust and without producing a matching shift in intended behavior. Destination preferences shifted most readily, often toward less sustainable and more niche choices; sustainability perceptions improved without motivating corresponding action; and transport choice showed the most limited influence of the three domains, with AI expanding awareness of alternatives more than it changed intended plans. These findings provide the first empirical evidence of how GenAI travel recommendations influence decision outcomes across destination choice, sustainability awareness, and transport behavior, informing both responsible AI design and efforts to steer tourism toward lower-impact patterns.
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The aviation sector is one of the largest sources of greenhouse gas (GHG) emissions, accounting for 2% of global CO2 emissions in 2022, with emissions potentially tripling by 2050 without intervention. In light of these events, the most promising avenue to cut emissions is through the use of Sustainable Aviation Fuels (SAF), although their impact remains limited due to numerous barriers that do not allow SAF blend ratios above 50%. Therefore, the main objective of this research is to systematically investigate the current barriers to blending limits of SAF specified under existing regulations and develop a comprehensive strategy which mobilises stakeholders. While existing literature addresses future uptake of SAF blends, identified barriers and coupled strategies are unclear, underdeveloped and dispersed, with regulatory mechanisms at times inefficacious. Furthermore, although collaboration among stakeholders is encouraged, it is unclear what roles individual stakeholders should take on to approach certain problems.

The research was conducted using a qualitative approach. The sample was composed of 14 specialists ranging from different key stakeholder groups. These key stakeholder groups were largely located in the higher rungs of the participation continuum, a model used in the stakeholder analysis which placed stakeholders along the continuum based on their level of participation in the SAF ecosystem. Semi-structured interviews then collected data, which were translated into codes. Using the Technological Innovation System (TIS) and its seven building blocks as a framework, all identified codes were grouped under one of the TIS building blocks. Based on this, three analyses were performed in parallel: barriers of SAF blending were identified, SAF production methods were compared against one another based on method-specific barriers, and strategic measures were formulated to overcome identified barriers alongside the actors who are responsible for enacting them. This, however, deviated from the TIS framework in the sense that it formulated a strategy for an entire industry and how stakeholders can collaborate as opposed to the formulation of a strategy for a single firm.

SAF blending above 50% is found to hold little to no priority among the SAF industry, which rather prioritizes upscaling of available capacity. This is because there is currently too little blend component available to achieve high blend percentages, regulatory limits do not instil an urgency to increase blends due to being small in number, and SAF supply methodologies are configured such that all SAF is blended to the bare minimum mandated. Only when such barriers are removed, and more blend component becomes available in the future, an increase in blend ratios and removal of the blend wall will be necessitated to achieve a higher sustainability impact of SAF in flight.

For SAF itself, it is found that the majority of TIS building blocks remain incompatible or partly incompatible. Product performance and quality are sufficient to some degree given that SAF can already be used in existing aircraft, but remain limited to blends of 50%. Product price is largely incompatible, the most cost-efficient SAF still being at least twice as expensive as conventional fuel due to energy-intensive processes and lack of technological maturity. The production system is similarly incompatible, projected to produce insufficient quantities of bio-SAF and e-SAF by 2030 due to long construction times and limited financial resources. Institutions and regulations are partly incompatible as they are widely in place but remain scattered and unclear. Network formation and coordination also remain partly incompatible, with limited participation and coordination concerning sustainability transitions. Uptake among customers remains limited due to their lack of knowledge and trust in SAF combined with the limited means by airlines to communicate. Only complementary infrastructure and services are fully compatible.

In terms of comparison between production methods, hydro-processed esters and fatty acids (HEFA) performs the best concerning product price and production system because it is a more mature technology. On the other hand, alcohol-to-jet (ATJ), catalytic hydrothermolysis jet (CHJ), and Fischer-Tropsch (FT) are still underdeveloped and more expensive, yet fall under the same mandated share of bio-SAF as HEFA, which causes them to be minimally stimulated. However, given HEFA’s limited impact due to its feedstock constraints, FT, ATJ, and CHJ technologies show future promise because they hold more potential with respect to unlocking the blend limit and have a larger pool of feedstock available. The same holds for synthetic SAF (e-SAF), although its energy-intensive processes remain a large bottleneck for future upscaling.

Paired with each identified key challenge comes an array of measures and actors that enables the industry to overcome these challenges. Mandates and regulations alongside incentives and subsidies most commonly contribute to bridging challenges concerning price, production system, and regulations. Meanwhile, product quality, performance, and infrastructure require further developments in technology and designated infrastructure. For network formation, stakeholder coordination, and customers, emphasis is more often placed on knowledge building and sharing, networking, and raising awareness. Depending on the context of the challenges and coupled measures, different levels of participation are required among stakeholders.

From these findings, the research reveals a comprehensive overview of barriers to large-scale SAF adoption. The application of the TIS framework in a multi-actor system broadens the perspective on barriers and strategies beyond the level of individual firms, illustrating that the strategies to help overcome the barriers are not enacted by a single stakeholder. Instead, to achieve the successful introduction of SAF, dynamic collaboration and coordination within the industry are required, with each stakeholder fulfilling different roles when faced with different challenges.
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Decarbonising heavy-duty road freight requires freight transport operators to invest in alternative drivetrains under rapidly changing technological, economic and policy conditions. Although existing research provides substantial insight into the techno-economic and system-level feasibility of hydrogen trucks, less is known about how operators evaluate hydrogen as an actual fleet investment. This study examines how freight transport operators assess hydrogen trucks in heavy-duty road freight. A qualitative research design combined literature and desk research with 24 semi-structured interviews, including 18 freight transport operators and six secondary stakeholders, followed by a descriptive questionnaire among all 18 operators. The operator sample covered small, medium-sized and large firms across a range of freight activities and levels of zero-emission engagement. The findings show that hydrogen is evaluated as a potential but currently conditional zero-emission option. Economic viability forms the dominant barrier, particularly because of high vehicle costs, high and uncertain hydrogen prices, low transport margins and limited customer willingness to pay. Battery-electric trucks are currently perceived as the more concrete zero-emission alternative, while hydrogen is mainly considered for operations where battery-electric deployment may face limitations related to distance, payload, charging time, grid capacity, utilisation or operational flexibility. Infrastructure, long-term policy confidence, firm capacity and uncertainty further shape investment decisions. Overall, hydrogen is evaluated as a relative and use-case-dependent investment option rather than as a mainstream zero-emission solution. ... Read more

Safety-critical organisations must remain almost perfectly reliable while adapting to labour shortages and sustainability demands. Employee-driven innovation can help, but how it can be organised without reducing reliability is poorly understood. This thesis studies KLM Engineering & Maintenance and its MRO Lab through a DMADV-based case study combining ten interviews, document analysis, nine months of observation and two surveys. The findings show that frontline engineers and mechanics have valuable ideas and are willing to contribute, but no clear route exists to move ideas forward; many barriers are deterring, causing employees to withhold ideas before sharing them. Innovation can nonetheless succeed when tied to a genuine operational need, even while constraints remain. Based on employee-prioritised measures, the Hub Feed was designed: a hybrid digital and physical platform where employees post ideas, colleagues respond and vote, and every post receives a visible status with an explanation. Verification indicates the design could close about half the gap towards the organisation's innovation maturity ambition. ... Read more

Airports are under increasing pressure to use existing capacity more efficiently while maintaining operational reliability, safety, and service quality. A critical process in this context is the aircraft turnaround, where multiple time-sensitive activities must be coordinated between airport operators, airlines, ground handlers, air traffic control, and other stakeholders. Digital twins offer potential to support this coordination by improving monitoring, prediction, and decision-making. However, these benefits depend on the maturity of the digital twin. Existing digital twin maturity models provide useful foundations, but they are not specifically designed for the multi-actor, time-critical, and safety-sensitive context of airport turnaround operations.

This thesis addresses the following research question: Which maturity assessment framework can guide the development of digital twins in airport turnaround operations?

To answer this question, this thesis develops a digital twin maturity assessment framework for airport turnaround operations. The research follows a Design Science Research approach, in which the problem is first explicated, requirements are derived from literature, and a framework is developed, refined, demonstrated, and evaluated through expert feedback. The resulting framework combines a baseline category and five maturity levels: Digital Model, Digital Shadow, Monitoring Twin, Predictive Twin, and Optimizing Twin. It assesses internal maturity across six dimensions: Data Infrastructure, System Integration, Predictive and Analytical Capability, Operational Decision Optimisation, Operational Situation Visibility, and Human Interaction and Trust. In addition, the framework distinguishes these internal capabilities from external implementation constraints, including data access, commercial sensitivity, decision rights, workflow integration, accountability, and safety.

The framework was demonstrated in the Schiphol context and evaluated with feedback from Schiphol and Vancouver International Airport. The demonstration showed that the framework can support a structured discussion about current capabilities, limitations, and development priorities. It also showed that maturity can differ across dimensions and may be limited by external implementation conditions. The main contribution of this thesis is therefore a context-specific assessment framework that helps airports move beyond the question of whether they have a digital twin, towards understanding what the digital twin can support, what limits its use in practice, and what should develop next. ... Read more

Women feel less safe than men in public transport environments. In the Netherlands, young women make up the biggest user group, while they also report feeling most unsafe in public transport stations. While research on perceived safety is extensive, the effects of temporal patterns remain underexplored, despite evidence that they directly influence how social and environmental factors shape perceived safety. The multisensory experience of perceived safety has also been overlooked, as most identified factors are visual, yet people experience their surroundings through sight, smell, and hearing.

This research aimed to deepen the understanding of temporal factors and sensory experiences at railway stations. Women aged 18 to 35 were the target group, as they are both the largest user group of Dutch public transport and the group that feels most unsafe there, making them experts in their own experiences. Larger railway stations were selected as the research setting because multiple modes of transport and facilities converge there. Preliminary observations provided a strong understanding of temporalities and sensory factors, while interviews with seventeen young women generated rich insights. Through thematic analysis, the temporal and sensory factors were investigated.

Day-night cycles are considered the most influential temporal pattern, especially when people are absent and social incivilities are perceived as present, such as loud talking or screaming, and the smell of alcohol or weed. The smell of urine also evokes unsafe feelings. Construction periods affect both social and environmental factors by reducing visibility, lighting, and the presence of people. Rush hours and shop opening hours determine how many people are at a station, adding to the lively sounds of railway stations, while weather and seasonal shifts mostly influence people’s mood rather than their perceived safety directly. Social factors appear most influenced by temporal patterns, with environmental factors playing a supporting role. This study highlights the influence of temporal patterns on perceived safety and its multisensory experience, with sight most notable, followed by sound and smell. These findings informed practical recommendations for designing railway stations that better accommodate the
temporal and sensory experiences of young women. ... Read more

Small railway stations serve as essential nodes in the daily mobility of travelers in the Dutch mobility system, yet they are overrepresented among the lowest-scoring stations in research on travelers’ experiences over the last five years. Building on the Capabilities Approach, this research considers perceived safety as a condition that influences whether the presence of small railway stations ensures equal accessibility for all travelers. Therefore, this research examines how travelers experience safety at small Dutch railway stations and explores how these insights can inform the design and development of these stations. By using an exploratory and descriptive qualitative research design, interviews were conducted with travelers at four small stations associated with the lowest scores in the Station Experience Monitor of NS in 2024. Additionally, in-depth interviews with experts in station design, safety, and public transport were held to gain insight into governance structures, design principles, and safety interventions.

The findings reveal how perceived safety is shaped by multidimensional and overlapping dynamics between temporal, spatial, social, and personal factors. Temporal conditions, particularly evening and nighttime travel, as well as gender identity, act as an amplifying lens through which the other factors are interpreted and experienced. Moreover, travelers identifying as women frequently adopted coping behaviors, such as arranging pick-ups or calling someone, thereby relying on their social networks. Travelers identifying as men often described their gender as a protective factor. Furthermore, the interviews with experts indicated that institutional dynamics, including fragmented responsibilities and difficulties regarding data sharing, further complicate the specific contexts of small railway stations that influence perceived safety.

At the same time, current monitoring tools do not include the complex nature of experienced safety and the related dynamics between the different factors influencing it. This study suggests that small railway stations deserve more attention in governance and monitoring frameworks. Creating station environments where travelers feel comfortable contributes to positive travel experiences and highlights perceived safety as a crucial condition for realizing equal mobility and accessibility. ... Read more

Structural changes in the travel behaviour of rail passengers following the COVID-19 pandemic have led to a strong weekday asymmetry in passenger demand. Demand is becoming more concentrated on the Tuesdays and Thursdays while Monday, Wednesday and Friday have seen a decline in passenger demand. In response a new policy was introduced at the Netherlands Railways (NS) called weekday differentiation. This policy reallocates unplanned servicing activities to low-demand weekdays allowing a higher availability of rolling stock on Tuesday and Thursday. Its implementation is however troubled with low operational performance. Meaning that due to operational constrains only part of the plan is successfully performed. This thesis researches how the robustness of weekday differentiation can be improved by optimising the allocation of rolling stock types to weekday differentiation over a week. The robustness is measured by the ability of the model to fill the weekday differentiation moments, also improving buffers at the weekday differentiation locations and minimizing deadheading. A MILP model is developed to represent the rolling stock flows. The model is an assignment model that assigns rolling stock to one of several states including passenger service and weekday differentiation opportunities. The model captures the trade-off between the passenger service that is rigid and the limited operating room to assign rolling stock units that are not active to the proper tasks. Some computational experiments are conducted in this thesis to analyse the model workings and the outcome of different variants of the model. The results demonstrate that targeted policy interventions can increase the number of successfully allocated rolling stock units while always maintaining careful consideration for the timetable. The findings provide support for refining the current weekday differentiation policy and offer insights for the NS to improve weekday differentiation productivity. ... Read more

Urban public transport networks are increasingly recognised as essential instruments for achieving sustainable, accessible, and inclusive cities. In the context of growing environmental pressures and policy ambitions, such as the transition toward “autoluw” cities, understanding how these networks are planned and developed has become critical. While existing literature extensively addresses individual technical, economic, and environmental factors, limited attention has been given to how social factors interact with these dimensions within planning and development processes. This research aims to address this gap by examining the influence of social factors and considerations on the design and implementation of urban public transport networks, using Amsterdam as a case study. A qualitative case study methodology was employed, centred on semi-structured, in-depth interviews with two groups: domain experts and civil servants involved in the Amsterdam context. These insights were complemented by a spatial (GIS) analysis of the current transport network and a document analysis of municipal strategies and future plans. The research specifically focused on the districts of Amsterdam Noord and Zuidoost, selected for their contrasting spatial and socio-economic conditions. The study distinguishes between long-term planning (strategic visions) and development phases (implementation), enabling a comparative assessment of how different factors influence each stage. The findings reveal that, although social factors, such as accessibility, equity, and socio-economic inclusion, are increasingly acknowledged in planning discourse, their actual influence differs from project to project. In long-term visions, social objectives are often prominently articulated. However, during the development and implementation phase, these considerations are frequently deprioritised due to financial constraints and other factors. Furthermore, the research highlights that factors are often indirectly incorporated through other categories, rather than being explicitly assessed. In the Amsterdam case, spatial disparities between districts persist, with Noord facing technical integration challenges and Zuidoost reflecting socio-economic inequalities, causing a reliance on public transit in a network less robust than other parts of the network. While planned interventions aim to address these issues, the translation of socially driven goals into concrete network improvements remains difficult. Overall, this study concludes that the role of social factors is hard to determine in practice, despite the stated importance of social factors to actors in the different processes. Strengthening their explicit integration, particularly in the transition from planning to implementation, is essential for developing more equitable and effective public transport networks. ... Read more

This thesis examines how the Dutch legislative and institutional framework determines the opportunities and limitations for non-pharmaceutical fulfilment providers in the B2C fulfilment of medicines. It explores the legal, organisational and market conditions that would allow a non-pharmaceutical company to offer an e-commerce fulfilment service that complies with Good Distribution Practice (GDP), with using PostNL Fulfilment as a case study. An exploratory mixed-methods research design is employed, combining literature and desk research on the Dutch pharmaceutical supply chain and legislative context, a stakeholder analysis, semi-structured interviews with pharmacists and other stakeholders, and the development of eight fulfilment scenarios. These scenarios are analysed using a framework of legal requirements and market-oriented design criteria. An actor-level implication analysis then assesses the institutional and administrative consequences.

The results show that pharmaceutical logistics in the Netherlands are regulated by a pharmacy-focused licensing system based on roles and locations, in which pharmacists remain responsible for dispensing medicines and ensuring patient safety. Non-pharmaceutical participation is therefore only possible through carefully regulated hybrid arrangements that ensure compliance with GDP, verifiable separation of responsibilities and robust contractual oversight. While none of the examined scenarios are explicitly on legal basis, the feasibility decreases as the executing party's role becomes more similar to that of a full logistics back office, comparable to the operational structure typically observed in conventional non-pharmaceutical fulfilment services. This is due to interpretative grey areas at the interface between dispensing and logistics, as well as the centralisation of multiple pharmacies and the associated distribution of roles and medication flows. Market feasibility is greatest in predictable segments with large volumes (e.g. repeat prescriptions), although it remains structurally constrained by the highly regulated nature of the pharmaceutical supply chain, which is characterised by a limited number of dominant actors who largely shape market access and operational conditions. In general, scalable implementation requires step-by-step expansion and clarification of regulations/legislation and governance designs that can be monitored and audited.
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Temporary railway timetables are implemented during periods of disrupted operations, such as planned track closures, and operate under constrained conditions. Temporary timetables lack quantitative methods to assess their overall performance and systematic comparison. This paper introduces an approach to quantify the effectiveness of temporary railway timetables. Timetable effectiveness is defined as the ability of a temporary timetable operating under constrained conditions to maintain operable, stable, and robust train operations under deterministic and stochastic variability. Based on this definition, a multi-criteria evaluation framework is proposed that integrates four performance indices: capacity utilization, stability, robustness, and operability. Existing timetable attributes are reformulated to reflect constrained operating conditions. In addition, a new timetable attribute, operability, is introduced to capture the executability of infeasible timetables. The framework aggregates the indices into a single Temporary Timetable Effectiveness (𝑇𝑇𝐸) indicator. The proposed methodology is demonstrated through a real-world case study of a planned track closure on the Dutch railway network. Multiple temporary timetables are quantified and compared using microscopic simulation. The results show that the framework is capable of distinguishing both marginal and substantial differences between alternative timetable designs and making trade-offs between performance indices explicit. The proposed framework provides a systematic quantitative assessment and comparison of temporary railway timetables.
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Designing railway stations is complex due to the diverse interests that must be brought together in an integrated design. One way to address this is by involving people in the design process. ProRail has plans to build four new stations along the Oude Lijn (the railway line between Leiden and Dordrecht): Schiedam Kethel, Rijswijk Buiten, Dordrecht Leerpark and Rotterdam van Nelle. ProRail was looking for a digital, upscalable method to determine the design preferences of a representative group. In this research, the focus was therefore on the following main research question: How can design choices for small railway stations along the Oude Lijn be aligned with user preferences through an appropriate digital participation approach? Scientific literature, Spoorbeeld documents and interviews are used to determine relevant design factors to choose from when creating attractive stations. The resulting set of factors was large and existing participation methods were unable to handle this level of complexity. Therefore, a new survey method was developed that uses conditional randomization. In this survey, (future) users were asked to indicate their design preferences by assigning points. The set of factors has been divided into two groups with conditional randomization to make the selection task manageable for respondents. The results showed that social safety, accessibility, and greenery were the most important groups of factors. The survey attracted many respondents and ProRail is advised to use the developed survey in the future. This method can also be applied to other complex design projects. Distributing a survey among future travelers should be combined with interviews with other important stakeholders. Residents' evenings already organized by ProRail can be used to discuss the factors from the survey further. ... Read more

As cities pursue ambitions to become emission-free, low-emission zones (LEZs) for passenger cars are likely to become more restrictive over time and may evolve into zero-emission zones (ZEZs), where fossil-fuel vehicles are no longer permitted. While such restrictive policies aim to accelerate decarbonisation, they simultaneously raise distributive concerns, as access to urban space becomes subject to compliance. This research examines under what conditions a ZEZ for passenger cars can be implemented in a socially equitable manner in Amsterdam, and which groups are most likely to bear the associated burdens. To address this question, a conceptual framework grounded in egalitarian and sufficientarian justice perspectives is combined with empirical survey data. Accessibility is used as the central benchmark for evaluating equity outcomes. The analysis considers car dependence by trip purpose, perceived feasibility of switching to an electric vehicle (EV), willingness to adopt alternative modes, and an empirically constructed adaptation typology. The findings indicate that car dependence is primarily activity-specific and concentrated in social, care-related, and household-related trips rather than commuting. While 74.5\% of car-owning respondents are potentially adaptable to a ZEZ, 11.0\% are highly policy-dependent and 14.5\% are structurally insufficient, facing a tangible risk of accessibility loss. Vulnerability follows clear socio-demographic gradients: lower-income, lower-educated, and older residents are overrepresented among those facing structural constraints, with indications of spatial clustering in districts further from the city centre. The results suggest that a passenger-car ZEZ in Amsterdam may be feasible for many residents, but that its social equity depends on the conditions under which it is implemented. Its legitimacy rests on preserving a minimum level of accessibility and preventing existing accessibility gaps between socio-demographic groups from widening. A gradual and transparent implementation strategy, an initially limited zone, targeted support for groups at risk of accessibility loss, viable alternatives to private car use before enforcement, and continuous monitoring therefore emerge as key conditions. The study demonstrates that restrictive climate policy is not distributionally neutral and that equity outcomes depend fundamentally on policy design and accompanying measures. ... Read more

This research explores the role of mobility hubs as strategic interventions in the transition towards sustainable urban mobility, focusing on their effectiveness in achieving predefined policy goals. Mobility hubs are physical spaces designed to integrate various transportation modes, serving as multimodal transfer points. They are increasingly used by municipalities in the Netherlands to address urban challenges such as an increasing demand for mobility, limited public space, and the environmental impacts of private vehicle use. Despite their growing implementation, systematic ex-post evaluation of mobility hubs in relation to their policy objectives remains scarce. This research seeks to fill this gap by developing an ex-post evaluation framework for assessing the societal impacts of realised mobility hubs.

The study applies different methods, combining a literature review, policy analysis, expert interviews, and a case application. The literature review sets the theoretical foundation by examining sustainable mobility concepts and the role of mobility hubs in transport systems. Policy documents from the municipality of Amsterdam and the province of Noord-Holland were analysed to understand the goals and objectives behind the development of mobility hubs. These policy documents highlight broad ambitions such as enhancing accessibility, promoting modal shifts away from private car use, and improving public space. However, they often lack specific, measurable indicators for assessing effectiveness.

Empirical data was gathered through semi-structured expert interviews with municipal representatives, provinces and developers involved in mobility hub development. These interviews provided insights into the current practices, challenges, and expectations for evaluating the effectiveness of mobility hubs. The findings from the interviews informed the creation of the ex-post evaluation framework, which includes indicators for measuring the contribution of mobility hubs to societal goals. Further, it was revealed that current practices aimed for moving from monitoring towards evaluation.

A key aspect of this research was testing the evaluation framework through a case application of the Appeltjesmarkt mobility hub in Amsterdam. This case application examined the feasibility, relevance, and practicality of applying the framework to a real-world example. The findings revealed that quantitative data on usage is readily available, evaluating broader impacts such as changes in travel behaviour and social cohesion remains challenging. The case study also highlighted the importance of contextual factors, such as the urban setting and hub size, in influencing the evaluation process.

The research emphasises the need for adaptive, context-sensitive evaluation frameworks, that can account for the diversity of mobility hubs and their varying roles. The proposed framework provides a practical tool for municipalities and stakeholders to assess the effectiveness of mobility hubs and supports evidence-based decision-making in the development of mobility hubs. This study contributes to bridging the gap between policy ambitions and the actual performance of mobility hubs. ... Read more

Large offshore projects have been relying on effective risk management practices that are initiated during tender phases. These projects are characterized by high technical complexity, involve many project actors, and interface dependencies between them. As projects transition from tender to execution, the focus shifts to evolving operational risks, without seeing the contextual and underlying reasons behind it. Risk information and decision logic are often fragmented that contributes to reduced project performance. The financial influence is significant, as risk contingencies can account for 10-12% of total project value. While successfully exploited opportunities or omitted risks may not produce visible effects, insufficient risk treatment can result in adverse outcomes severe enough to reduce contractor profit margins. This thesis investigates how quality of project risk transfer and continuity can be improved during handover from tender to execution in offshore energy projects. This study has adapted a qualitative research design that combines literature review, two in-depth case studies of offshore energy projects executed by major marine contractor, Boskalis. Additionally, this research presents semi structured interviews with key stakeholders involved in the case study projects as well as actors in general of similar expertise working at the company. This analysis is guided by theoretical perspectives from Knowledge Management and Transition Management, that frames risk knowledge as both strategic organisational asset, and dynamic construct shaped by feedback loops, time delays and organisational interfaces. The findings indicate that risk transfer discontinuity is caused due to weakness in knowledge continuity and failure in bidirectional flow of information across project phases. The company demonstrates strong institutional capabilities and expertise in the field of risk engineering, tender and project management. So, it can also be said that continuity is not due to lack of tools, technical knowledge, or formal procedures. There are critical breakdowns during negotiation stages, planning handovers, and team transitions, where contextual reasoning, assumptions and tacit knowledge are not sufficiently transferred. This thesis concludes that improving risk transfer quality needs a shift in focus from static documentation of risk registers, towards managing transition moments, strengthening feedback mechanisms, and preserving common knowledge across organizational boundaries. Practical recommendations are proposed in the end, including targeted negotiation feedback gates, operational involvement in tendering, and adaptive practices to capture lessons learned. ... Read more

Accessibility has long been used in transportation studies as a way to compare the utility derived by individuals from the transport system. Furthermore, accessibility is also a helpful indicator in studying distributive justice issues in the field of transportation. On the other hand, a vast literature has studied inequalities, in terms of income and employment among other variables, between ‘cités’ neighbourhoods, in France as a whole and in the Paris Urban Area more specifically. In this study we aim to identify how these inequalities could be associated with poor accessibility to jobs and other key services in these areas. GTFS data from the Paris Urban area is used to estimate time travels between census tracts. Using this data as input, accessibility to facilities belonging to different types of key services from an area is then computed using both travel time and fare cost. These accessibility results are then analysed, using a clustering method and a spatial regression model. Results obtained show that in general areas with lower income tend to perform more poorly accessibility-wise, but that a variety of situations exist for areas with average income. ... Read more

The accelerating transition toward electric mobility is a key component of global efforts to decarbonise transport systems and achieve long-term climate goals. As electric vehicle (EV) adoption increases, the demand for accessible, reliable, and efficient public charging station infrastructure (PCSI) grows. Public charging networks enable the practical use of EVs while supporting renewable energy integration, reducing greenhouse gas emissions, and improving equitable access to sustainable transport.

In the Netherlands, early policy support and public–private cooperation have resulted in one of the most advanced EV charging ecosystems worldwide. However, as the market matures, local authorities face increasingly complex decisions regarding how to plan and manage charging infrastructure. PCSI deployment involves trade-offs between accessibility, economic viability, and system efficiency, while stakeholders operate under different governance models and local conditions. Despite the availability of planning tools and growing experience, uncertainty remains about how different roll-out strategies perform across diverse urban contexts.

This research evaluates how different PCSI roll-out strategies perform across varying urban-infrastructural contexts in the Netherlands. The objective is not to identify a single optimal strategy but to provide empirical insight into how strategy effectiveness depends on local conditions. The central research question is:

How do different roll-out strategies for public EV charging station infrastructure perform across varying urban-infrastructural profiles, as measured by key performance indicators?

To address this question, the study combines spatial, socio-economic, and operational data in a quantitative multiple-case study framework. Local authorities are first classified into urban profiles using a two-step clustering method based on neighbourhood-level data from Statistics Netherlands (CBS), including income, address density, and land area. Next, real-world roll-out strategies are identified from policy documents and categorised according to governance model (concession-based or open market) and planning style (reactive, strategic, or data-driven). Infrastructure performance is then evaluated using three key indicators derived from the NDW LINDA dataset: charging station utilisation rate, energy throughput, and number of unique users. These indicators are combined into a composite performance index and statistically analysed using ANOVA and Tukey tests.

The results show that the effectiveness of roll-out strategies varies significantly across urban-infrastructural contexts. Data-driven and strategic planning approaches consistently outperform purely reactive request-based models in terms of utilisation and delivered energy. In dense urban environments, open-market governance models perform competitively due to increased innovation and network expansion by multiple charging point operators. In suburban and rural contexts, concession-based models provide greater stability and more equitable spatial coverage through coordinated planning.

Overall, the findings demonstrate that there is no universally optimal roll-out strategy. Instead, infrastructure performance depends on the alignment between governance structure, planning approach, and the spatial and socio-economic characteristics of local authorities. These results provide empirical evidence to support more context-sensitive planning of public EV charging infrastructure and contribute to improved decision-making for policymakers and infrastructure operators. ... Read more

Decarbonizing island energy systems is challenging due to isolation, high reliance on imported fossil fuels and variable renewable generation. Tilos, a small Greek island, has become a model for sustainable island development through the EU-funded TILOS project, which combined wind, solar and sodium–nickel chloride (NaNiCl₂) batteries. While successful, the system’s limited flexibility for long-duration storage motivates exploring alternative solutions.

This thesis evaluates whether a hybrid system combining vanadium flow batteries (VFBs) with hydrogen storage (H-BESS) could deliver greater societal value than the existing NaNiCl₂ configuration. The analysis applies a Social Cost–Benefit Analysis (SCBA) framework, extending beyond techno-economic comparisons to include environmental and social impacts. Net Social Benefit (NSB) and Levelized Cost of Storage (LCOS) serve as the main decision metrics.

A MATLAB-based computational model simulated Tilos’ annual demand (3,108 MWh) and renewable supply (2,553 MWh) under three scenarios: pessimistic, balanced, and optimistic. Results show the hybrid system increases renewable utilization (90.1% vs. 85.4%), reduces curtailment (–118 MWh/year), and modestly improves energy autonomy. Economically, the hybrid system achieves lower LCOS in balanced (€510/MWh) and optimistic (€263/MWh) scenarios compared to NaNiCl₂ (€656–555/MWh). NSB outcomes range from –€156k (pessimistic) to +€990k (optimistic), with sensitivity analysis identifying VFB capital cost as the most critical factor.

Beyond economics, the hybrid system delivers additional societal value through CO₂ reductions (21.2 t/year), potential hydrogen use in other sectors and near-complete recyclability of vanadium electrolytes.

The study concludes that hybrid VFB–H₂ systems can provide superior societal benefits under favorable cost trajectories. Policymakers should consider phased deployment on Tilos and support measures for VFB cost reduction and hydrogen market development, with potential replication across other Greek islands. ... Read more

Peripheral regions in Europe face persistent demographic and economic challenges. Population decline, ageing, and limited job opportunities reduce the vitality of these regions, while shrinking public transport services further undermine accessibility and quality of life. In this context, public transport interventions, such as the development of new railways, are often presented as a strategic solution to enhance regional connectivity, improve economic prospects, and maintain the attractiveness of peripheral areas. Railways are seen not only as technical infrastructure but as catalysts for broader socio-economic renewal.

Yet, despite these high expectations, it remains difficult to determine whether such projects truly achieve their intended effects. A complication is the limited availability of ex-post evaluations. Large-scale infrastructure projects are typically judged by pre-opening forecasts, such as ridership projections or symbolic milestones, rather than by systematic ex-post, long-term analyses of social, economic, and spatial outcomes. Existing studies in Europe are relatively scarce. This lack of robust empirical evidence complicates the ability of policymakers to draw lessons for future projects such as the Lelylijn or the Nedersaksenlijn.

This research investigates whether public transport investments enhance the attractiveness of peripheral regions. Focusing on the Hanzelijn as a case study, it examines contextual conditions and mechanisms that shape regional development. The aim is to develop a conceptual model and identify the conditions under which such interventions succeed or fail, offering insights for policymakers and planners...... ... Read more