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on Project, Program and Portfolio Management |
| By: | Hümmer, Matthias |
| Abstract: | Purpose: To integrate fragmented literature on time pressure in megaprojects and develop a mechanism-oriented explanation of how pressure emerges, escalates, and affects project outcomes. Design/methodology/approach: A conceptual synthesis draws together research on megaproject governance and performance, psychological theories of stress and decision-making, and studies on team learning and project execution. The article develops a dual-pathway framework that distinguishes planning-origin and execution-origin time pressure. Findings: Time pressure in megaprojects arises both from front-end schedule compression and from execution-stage deviations that trigger recovery action. Under conditions of high interdependence, limited capacity, and elevated success pressure, both pathways can activate a self-reinforcing Vicious Pressure Circle in which acceleration, process bypassing, rework, lower acceptance thresholds, and re-planning intensify subsequent pressure. Expertise, psychological safety, modularization, and reference-class forecasting operate as moderating mechanisms. Research limitations/implications: The framework is conceptual and therefore requires empirical testing across project types, governance regimes, and lifecycle phases. Practical implications: Project organizations should distinguish the origin of pressure, monitor requirement-capacity mismatches, protect reporting climates, and use front-end realism and modular design to interrupt escalation loops. Originality/value: The article offers a unified conceptual vocabulary and explicit propositions that connect megaproject governance, cognitive mechanisms, and organizational learning. |
| Date: | 2026–03–13 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:3rq8c_v1 |
| By: | Phoebe Koundouri; Maria Chourdaki; Konstantinos Dellis; Kit England |
| Abstract: | Europe, as the fastest warming continent, faces elevated climate risks coupled with a climate adaptation finance gap, defined as the difference between the costs of achieving an adaptation target and the amount of finance available for adaptation (UNEP, 2024). The EU needs to invest almost EUR 70 billion per year in climate adaptation up to 2050 (Monteleone et al., 2026). However, current funding relies heavily on public sources, highlighting the urgent need for private sector involvement (CPI, 2023). Regions and cities in the EU face barriers in their effort to muster financial resources to translate adaptation strategies into tangible projects to promote climate and socioeconomic resilience. The Adaptation Investment Cycle (AIC), developed in the HEU Pathways2Resilience project, is a six-step process designed to help regions overcome barriers to financing climate adaptation by offering a step-by-step approach that builds local capacity and bridges gaps between planning and implementation. This paper maps the steps of the AIC to common adaptation finance barriers -economic, financial, awareness, behavioral, and institutional-, highlights their impact on raising and leveraging capital to strengthen regional resilience and assesses innovative financial sources and instruments tailored to regional needs. Finally, we emphasize concise frameworks for sub-national adaptation finance and contribute to the literature on regional resilience. |
| Keywords: | climate finance, climate adaptation, adaptation finance barriers, Adaptation Investment Cycle (AIC), public sector, investors |
| Date: | 2026–03–10 |
| URL: | https://d.repec.org/n?u=RePEc:aue:wpaper:2608 |
| By: | Pedraza, Alvaro; Williams, Tomas; Zeni, Federica |
| Abstract: | Although the climate impact of carbon abatement is geographically invariant, this paper documents limited geographic fungibility in voluntary carbon markets. Firms disproportionately retire offsets in countries where they operate. The paper contrasts an Information Channel, whereby local presence improves project screening, with a Goodwill Channel, whereby supporting local projects enhances reputational visibility. The evidence supports the latter. Offsets retired within firms’ operational footprints exhibit systematically lower project quality than those sourced abroad, revealing a negative local quality gradient. This pattern persists with firm experience and generates equilibrium price-quality decoupling: in jurisdictions with concentrated local demand, prices become less responsive to project quality. The resulting distortions can generate a “market for lemons” dynamic, reallocating climate finance away from high-abatement-potential regions toward areas with greater multinational presence. Strategic corporate incentives thus weaken the allocative efficiency of voluntary carbon markets. |
| Date: | 2026–03–16 |
| URL: | https://d.repec.org/n?u=RePEc:wbk:wbrwps:11331 |
| By: | Garnett, Emma; Green, Judith; Steinbach, Rebecca; Lewis, Daniel |
| Abstract: | Digital technologies are increasingly enfolded in citizenship projects - from apps that contribute to the enactment of individual health maintenance for neoliberal citizens, through to more activist engagements using citizen-generated data for environmental justice. We use Sarah Pink and colleagues’ metaphor of ‘broken data’ to explore how one device – a commercially available pollution sensor – was anticipated and used in practice for such citizenship practices by volunteers in one city. The device, at one level, failed in many ways. It produced unreliable data doubles: digital representations of air that failed to correlate with users’ own embodied experiences or tacit knowledge. The data generated by the device failed to afford mitigating actions for personal citizenship responsibilities. The data generated could not be directly accessed, nor easily shared with others in ways conducive to collective action. The disconnects between haptic and digital data highlighted the instability of the sensor, as a hybrid of personal device and political tool. However, in grappling with their ‘broken’ air pollution data, participants mobilized different sensing capacities that afforded (with varying degrees of success) citizenship projects by enacting ‘responsible’ engagements with the city and other citizens, and with more activist imaginaries. Data practices, we suggest, happen alongside citizenship projects, but do not necessarily enable those projects. |
| Date: | 2026–03–14 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:ufkzr_v1 |
| By: | Yuliia Verheliuk (State Tax University) |
| Abstract: | State-guaranteed debt arises from borrowings by economic entities for the implementation of infrastructure projects under state guarantees, offering potential advantages provided that effective control mechanisms are in place and corruption risks are minimized. However, shortcomings in Ukraine's practice of managing guaranteed debt contribute to the growth of residents' indebtedness, which subsequently transforms into guaranteed debt, while a significant share of projects remains unimplemented, underscoring the need to improve the monitoring system. This study assesses the role of state-guaranteed debt within Ukraine's system of obligations, with particular attention to the challenges associated with its management and the provision of state guarantees. The research is grounded in a normative analysis of the legislative framework, the application of statistical methods to evaluate trends in guaranteed debt, and theoretical generalization of the fundamental principles underlying guaranteed debt management and the guarantee-granting process. The findings demonstrate that state-guaranteed debt constitutes a contingent liability arising from the inability of residents to meet debt obligations obtained under state guarantees. The lack of a clear methodology for assessing the creditworthiness of economic entities, the absence of a specialized management body, and non-transparent project selection procedures heighten corruption risks and pose threats to debt security. International experience indicates that ineffective management of guaranteed debt may generate a crowding-out effect on investment, thereby constraining economic development, while insufficient oversight of loan utilization intensifies pressure on the state budget. These circumstances call for a reassessment of existing approaches to the provision of state guarantees in order to ensure their effectiveness. Overall, deficiencies in the management of guaranteed debt in Ukraine, particularly limited transparency and inadequate creditworthiness assessment, create substantial fiscal risks. Addressing these issues requires improvements in the legislative framework, refinement of project selection procedures, and the establishment of a specialized management body to enhance efficiency and strengthen debt security. Further research should concentrate on developing clear criteria for assessing borrowers' solvency and designing an institutional framework for managing guaranteed debt aimed at reducing corruption risks and improving the effectiveness of state guarantees. |
| Abstract: | La dette garantie par l'État résulte des emprunts contractés par des entités économiques en vue de la mise en œuvre de projets d'infrastructure sous garanties publiques, offrant des avantages potentiels à condition qu'un contrôle effectif soit assuré et que les risques de corruption soient minimisés. Toutefois, les imperfections de la pratique ukrainienne en matière de gestion de la dette garantie contribuent à l'augmentation de l'endettement des résidents, lequel se transforme ultérieurement en dette garantie, tandis qu'une part significative des projets demeure non réalisée, ce qui souligne la nécessité d'améliorer le système de suivi et de contrôle. La présente étude vise à évaluer la place de la dette garantie par l'État dans le système des engagements de l'Ukraine, en mettant l'accent sur les défis liés à la gestion et à l'octroi des garanties publiques. La recherche repose sur une analyse normative du cadre législatif, sur l'application de méthodes statistiques afin d'évaluer les tendances de la dette garantie, ainsi que sur des approches théoriques permettant de généraliser les principes fondamentaux de la gestion de la dette garantie et du processus d'octroi des garanties publiques. Les résultats montrent que la dette garantie par l'État constitue un passif éventuel résultant de l'incapacité des résidents à honorer les obligations d'emprunt contractées sous garanties publiques. L'absence d'une méthodologie claire d'évaluation de la solvabilité des entités économiques, le manque d'un organe spécialisé de gestion et l'insuffisance de transparence dans les procédures de sélection des projets accroissent les risques de corruption et menacent la sécurité de la dette. L'expérience internationale démontre qu'une gestion inefficace de la dette garantie peut engendrer un effet d'éviction des investissements et freiner le développement économique, tandis qu'un contrôle inadéquat de l'utilisation des fonds empruntés alourdit la charge pesant sur le budget de l'État. En définitive, les lacunes identifiées dans la gestion de la dette garantie en Ukraine, notamment le déficit de transparence et l'absence d'une évaluation systématique de la solvabilité des emprunteurs, génèrent des risques budgétaires significatifs. Il apparaît nécessaire d'améliorer le cadre législatif, de perfectionner les procédures de sélection des projets et de créer un organe spécialisé de gestion afin d'accroître l'efficacité des garanties publiques et de renforcer la sécurité de la dette. Les recherches ultérieures devraient se concentrer sur l'élaboration de critères clairs d'évaluation de la solvabilité des emprunteurs ainsi que sur la mise en place d'un mécanisme institutionnel de gestion de la dette garantie, dans le but de réduire les risques de corruption et d'améliorer l'efficacité des garanties de l'État. |
| Abstract: | Гарантований державою борг виникає внаслідок запозичень суб'єктів господарювання для реалізації інфраструктурних проєктів під державні гарантії, що створює потенційні переваги за умови належного контролю та мінімізації корупційних ризиків. Водночас недосконалість української практики управління гарантованим боргом призводить до зростання заборгованості резидентів, яка трансформується у гарантований борг, тоді як значна частина проєктів залишається нереалізованою, що свідчить про потребу вдосконалення системи моніторингу. Дослідження спрямоване на оцінку місця гарантованого боргу в системі зобов'язань України з акцентом на проблеми управління та надання державних гарантій. Методологічною основою роботи є нормативний аналіз законодавчої бази, застосування статистичних методів для оцінки тенденцій динаміки гарантованого боргу, а також теоретичне узагальнення базових засад управління гарантованим боргом і процесом надання державних гарантій. Обґрунтовано, що гарантований державний борг має характер умовного зобов'язання, яке виникає у разі неспроможності резидентів виконувати боргові зобов'язання, отримані під державні гарантії. Встановлено, що відсутність чіткої методики оцінки кредитоспроможності суб'єктів господарювання, спеціалізованого органу управління та прозорих процедур відбору проєктів підвищує корупційні ризики і створює загрози борговій безпеці держави. Міжнародний досвід засвідчує, що неефективне управління гарантованим боргом може спричиняти ефект витіснення інвестицій і гальмувати економічний розвиток, тоді як неналежний контроль за використанням залучених позик посилює навантаження на державний бюджет. Узагальнення результатів дає підстави стверджувати, що існуючі недоліки управління гарантованим боргом в Україні, зокрема недостатня прозорість та відсутність належної оцінки кредитоспроможності позичальників, формують суттєві фіскальні ризики. Це зумовлює необхідність удосконалення законодавчої бази, процедур відбору проєктів і створення спеціалізованого органу управління для підвищення ефективності державних гарантій та зміцнення боргової безпеки. Перспективи подальших досліджень пов'язані з розробленням чітких критеріїв оцінки платоспроможності позичальників і формуванням інституційного механізму управління гарантованим боргом з метою зниження корупційних ризиків і підвищення результативності гарантійної політики держави. |
| Keywords: | economic development, investment projects, debt management, debt security, state guarantees, state-guaranteed debt |
| Date: | 2025–10–31 |
| URL: | https://d.repec.org/n?u=RePEc:hal:journl:hal-05533564 |
| By: | Phoenix, Daniel M. (Virginia Tech); Hatzisavvidou, Sophia |
| Abstract: | Net-zero commitments have become the dominant instrument of climate and energy governance. Hence, energy transitions are increasingly shaped by state-authored visions that project, stabilise, and legitimise visions of the future. Energy social science has developed rich discursive approaches to study conflicts around energy systems, infrastructures, and projects. However, it has paid comparatively less attention to two elements. The first is studying how comprehensive net-zero policy visions are constructed upstream – that is, before implementation and contestation unfold. The second is to combine different qualitative methods to address a single phenomenon. This paper addresses both gaps. It analyses net-zero governance as a formative site of political and symbolic work, where ecological limits, economic priorities, and technological assumptions are assembled into a coherent vision of transformation. The paper introduces an integrative qualitative framework for energy research. It combines discourse analysis, rhetorical analysis, and LLM-assisted interpretation. It shows its applicability using the Spanish government’s net zero policy commitments and their parliamentary contestations as a case study. The analysis shows that Spain’s net-zero governance operates through a politics of managed consensus, in which layered discourses and rhetorical performances absorb contestation while deferring to the future the more radical implications of ecological limits. The paper also responds to calls for methodological pluralism in energy research by demonstrating it in practice. Beyond the case study, the findings help explain why net-zero governance in Europe, while designed to build consensus, may itself generate the conditions for backlash. |
| Date: | 2026–03–09 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:2f5en_v1 |
| By: | Schulze, Meike |
| Abstract: | African governments are entering the geopolitical competition over critical raw materials with a growing sense of strategic confidence. While the AU-EU Summit in Luanda in November 2025 reaffirmed political commitments on both sides, European initiatives continue to lose ground. It is true that the Critical Raw Materials Act has expanded the EU's diplomatic footprint; however, its limited project pipeline and fragmented financing under the Global Gateway have left the bloc unable to match the speed and scale of competing offers notably from China, the Gulf States and the US. African partners expect cooperation on industrial projects and deeper integration into value chains. With stronger internal coordination and increased financing under the next Multiannual Financial Framework, the EU can strengthen both its ability to deliver and its credibility. |
| Keywords: | African Green Minerals Strategy (AGMS), African Union (AU), AU-EU summit, Critical Raw Materials Act, Global Gateway, China, Gulf states, value chains, Multiannual Financial Framework |
| Date: | 2026 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:swpcom:338236 |
| By: | Thomas Dulak; Guntram Wolff |
| Abstract: | Since the first green bond was issued in 2007, the market has expanded significantly and now accounts for around 3% of the global bond universe. Westudy the liquidity of green bonds. In particular, we are the first to investigategreen bonds’ daily trading volumes and frequency with a unique dataset fromEuroclear. Studying these dimensions of liquidity is particularly important in relatively small markets. Our dataset, covering the period 2020 to 2025, allows us todirectly compare green bonds with conventional bonds. We find that green bondsdo not suffer from a systematic liquidity disadvantage relative to conventionalbonds. On the contrary, they are traded in higher aggregate volumes, drivenby more frequent trading rather than by larger transaction sizes. These differences persist during periods of heightened market-wide stress. Within the greenbond universe, third-party certification is associated with higher trading volumesthrough more intensive trading when bonds are active, while green bonds funding more common project types are traded more regularly than bonds financingmore niche projects |
| Keywords: | Green bonds; Bond liquidity; Trading activity; Market stress; Certification |
| JEL: | G11 G23 Q56 |
| Date: | 2026–03–01 |
| URL: | https://d.repec.org/n?u=RePEc:eca:wpaper:2013/404323 |
| By: | Liang, Xiaofan (University of Michigan) |
| Abstract: | Artificial Intelligence (AI) promises to transform urban planning research, practice, and education, yet few curricula address “Urban AI”. This paper presents the pedagogical design of a pilot Urban AI course and argues for three meta learning goals: applying AI effectively and appropriately in urban challenges, addressing its social, environmental, and governance impacts, and developing normative judgements and professional identities around AI. Pilot teaching produced a knowledge graph connecting essential skills to these goals and a critical framework for AI use and reflection, grounded in analysis of 235 student reflection journals, alongside course evaluations, syllabus materials, and student projects (https://www.xiaofanliang.com/teaching/) . |
| Date: | 2026–03–11 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:g9cps_v1 |
| By: | Ashok Gulati (Indian Council for Research on International Economic Relations (ICRIER)); Deepak Guptа; Subhodeep Basu |
| Abstract: | India's electricity distribution system continues to face a structural imbalance. Publicly owned Distribution Companies (DISCOMs) bear the dual burden of universal service obligations and sometimes politically determined tariffs. This results in persistent financial losses, particularly in rural supply. While renewable energy expansion has accelerated nationally, it remains heavily centralised, doing little to alleviate the high cost of rural power delivery. Agriphotovoltaics (APV), the dual use of land for solar power generation while continuing agriculture, offers a structural innovation that can bridge this gap. By generating electricity directly within rural feeders, APV systems reduce transmission losses, defer infrastructure investments, and transform farmers from subsidised consumers into energy partners. Drawing on ICRIER’s pilot projects in Rajasthan and Odisha, the brief demonstrates how farmer-led APV models can align renewable energy deployment with livelihood enhancement. A sensitivity analysis of the Rajasthan pilot reveals that while capital subsidies can ease entry barriers, a remunerative Feed-in Tariff (FiT) of around INR 4.40/kWh is critical for ensuring long-term financial viability and scalability. The findings highlight the need for policy recalibration that recognises APV as both a decentralised energy solution and a rural development instrument that would be capable of improving DISCOM viability, enhancing farmer incomes, and advancing India's just energy transition. |
| Keywords: | Agriphotovoltaics, farmers-income, business models, Feed-in-Tariff, PM KUSUM, icrier |
| Date: | 2026–01 |
| URL: | https://d.repec.org/n?u=RePEc:bdc:ppaper:62 |
| By: | Narayanan, Sudha; Sakil, Abdul Zabbar; Kabir, Razin; Redoy, Md.; Belton, Ben |
| Abstract: | This project note summarizes insights from a three-year research project focused on an ambitious cluster intervention by the Department of Fisheries (DoF), Government of Bangladesh for shrimp farmers. In 2022, as part of a World Bank funded project, the Department of Fisheries organized smallholder shrimp farmers with contiguous ponds into clusters in Khulna, Satkhira and Bagerhat districts in southwest Bangladesh. Each cluster brought together 20-25 farmers, with pond sizes of at most 1.5 acres in size, to deliver training on best management practices, supply inputs, and encourage coordination. Group members were encouraged to follow a suite of management practices aimed at raising farm productivity, reducing the incidence of shrimp disease, and increasing the supply of raw material for processors. These measures included farming bagda shrimp (P. monodon)—Bangladesh’s main export species—in monoculture, raising shrimp stocking densities, stocking disease-free shrimp larvae (SPFPL), using factory-made feeds, deepening ponds, erecting biosecurity fencing, and coordinating stocking and harvesting activities with other group members. The costs of deepening ponds and adopting other improved management practices were borne by farmers themselves, but the clusters that made these investments received free SPF-PL and feed as incentives for doing so. The goal of this cluster intervention was to promote sufficient volumes of shrimp for processing plants for export, eventually paving the way for instituting traceability systems and group-based sustainability certification, increasingly a requirement in global retail markets. Even at the time of inception, the cluster program was intended as a time-bound two-year project that would end in 2025. |
| Keywords: | shrimp fisheries; evaluation; shrimp culture; farming systems; aquaculture systems; Bangladesh; Southern Asia; Asia |
| Date: | 2025–12–31 |
| URL: | https://d.repec.org/n?u=RePEc:fpr:prnote:179366 |
| By: | Cruz Romero, Roberto (Deutches Zentrum für Hochschul- und Wissenschaftsforschung (DZHW)); Stahlschmidt, Stephan |
| Abstract: | This study reconstructs and characterises the science-policy nexus in the field of artificial intelligence research in Germany, examining the alignment between normative policy goals and empirical research outcomes. Adopting a narrative policy framework, the research investigates transition dynamics across policy, scholarly, and innovation levels, tracing the interconnectedness in stages of patents, papers, and publicly funded projects. The research employs a two-pronged empirical approach: 1) identifying German contributions to AI research through patent citations and bibliometric data, and 2) linking these outputs to the policy instances that funded and enabled them. This methodology reveals the complex pathways through which policy intentions translate into research outcomes, highlighting the mostly indirect nature of this relationship. Key findings emphasise significant challenges in data quality and availability, particularly in linking research outputs to higher-level policy dimensions. While the study successfully identifies German-affiliated papers through patent and bibliometric datasets, it uncovers fundamental disconnections between stated policy objectives and actual research trajectories. These dimensions are compounded by administrative bottlenecks, asynchronous implementation settings, and entangled funding periods. The study concludes that AI development is heavily influenced by geopolitical and strategic decisions extending beyond academia, and that academic research into AI is part of a larger narrative of policy and political design. The study offers a framework for assessing the nuances of science-policy pathways while acknowledging the limitations of fully characterising this nexus. The systematisation presented serves as a foundation for future research, emphasising the need for comprehensive and coherent data sources to evaluate the phases and connections within scholarly and policy narratives. |
| Date: | 2026–03–05 |
| URL: | https://d.repec.org/n?u=RePEc:osf:socarx:mtz4d_v1 |
| By: | Simon Greenhill; Brant J. Walker; Joseph S. Shapiro |
| Abstract: | Projecting the effects of proposed policy reforms is challenging because no outcome data exist for regulations that governments have not yet implemented. We propose an ex ante deep learning framework that can project effects of proposed reforms by mapping outcomes observed under past regulations onto the legal criteria of proposed future policies (i.e., by “relabeling”). We apply this framework to study changes in jurisdiction of the US Clean Water Act (CWA). We compare our ex ante deep learning projection of jurisdiction under the Supreme Court’s Sackett decision against widely used projections from domain experts. Ex ante machine learning generates exceptional performance improvements over the leading domain expert model that the US Environmental Protection Agency currently uses, with 65 times more accurate identification of jurisdictional sites. We also develop an ex post deep learning model trained with data after policy implementation. Ex post deep learning performs best. Sackett deregulates one-third of all previously regulated US waters, particularly floodplains and pristine fish habitats, totaling 700, 000 deregulated stream miles and 17 million deregulated wetland acres. Deep learning can effectively project consequences of far-reaching regulatory reforms before they are implemented, when projections are both most uncertain and most useful. |
| JEL: | C45 D61 H11 H23 K32 Q25 Q53 Q58 R11 |
| Date: | 2026–03 |
| URL: | https://d.repec.org/n?u=RePEc:nbr:nberwo:34947 |
| By: | Mateos, Angel; Butt, Ali A; Kim, Changmo; Nassiri, Somayeh; Harvey, John |
| Abstract: | Caltrans jointed plain concrete pavements (JPCP) and continuously reinforced concrete pavements (CRCP) are currently designed for a 40-year life (based on 10% fatigue transverse cracking and 10 punchouts per mile criteria, respectively). While this is already a long-life design, there is the concern that it may not result in the minimum possible life cycle cost and environmental impacts. The current Caltrans Highway Design Manual (HDM), including the Rigid Pavement Design Catalog, and the Standard Specifications applicable to concrete pavements, are based on this 40 year design life. This study includes recommendations for the materials, design, and construction of concrete pavements aimed at extending the design life up to 100 years. These recommendations are based on existing knowledge and tools and indicate the changes necessary to Caltrans’s existingspecifications and practices. However, uncertainties remain in traffic load and climate predictions, as well as the limitations of current durability and structural design models, all of which complicate efforts to accurately predict pavement life beyond the current 40-year standard. As part of this study, the web version of the Rigid Pavement Design Catalog has been updated to allow any design life up to 100 years. This study includes the pavement structural design, life cycle cost analysis (LCCA), and the environmental life cycle assessment (LCA) of three case studies, each designed for 40-, 60-, and 100-year lives. The increase in design life from 40 to 60 years required an increase in JPCP thickness of 0.05 ft. for all three case studies, which carried an increase in the initial agency construction cost of around 5%. The LCCA and LCA results indicate that increasing the design life from 40 to 60 years is expected to result in 3% life cycle agency cost savings and 24% life cycle infrastructure global warmingpotential (GWP) savings. Some road user cost savings were seen from fewer construction work zone (CWZ) closures. Smaller life cycle costs and GWP reductions were found when the design life increased from 60 to 100 years, due in part to the relatively high discount rate used in this study (3.2% per year) and the fact that the reconstruction activity for the 60-year design life already lay beyond the end of the 100-year analysis period adopted in this study. |
| Keywords: | Engineering, pavement design life, jointed plain concrete pavement (JPCP), continuously reinforced concrete pavement (CRCP), life cycle cost analysis (LCCA), life cycle assessment (LCA), global warming potential (GWP) |
| Date: | 2025–12–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt6k69q4rz |
| By: | Wu, Rongzong; Lea, Jeremy; Harvey, John; Guada, Irwin; Rahman, Mohammad |
| Abstract: | The first asphalt concrete long-life (AC Long Life) project was constructed in Los Angeles County on Route 710 (LA-710) near Long Beach in 2001/2004 and is now over 20 years old. Four more AC Long Life projects have been completed in California since then, three between 2011 and 2014 (TEH-5, SIS-5, SOL-5), and one in 2021/2022 (SAC-5). The goal of these AC Long Life projects was to achieve design lives of 30 years or 40 years (the standard Caltrans asphalt pavement design life was 20 years at the time). Measures taken to achieve those lives included the use of performance-related specifications for job mix formula approvals, higher compaction requirements, and the use of a three-layer asphalt concrete system for structural capacity. These measures required additional costs. Calculations indicate that the longer lives will result in life cycle cost reductions if they achieve the design lives. Hence, periodic performance evaluations are important, which is the purpose of this technical memorandum. Extensive material sampling and structural evaluation were conducted regularly on the LA-710 and TEH-5projects. This technical memorandum reviews the available performance data, summarizes the material testing and structural evaluation data for the LA-710 and TEH-5 projects, and compares the as-built materials with statewide medians. The cracking, patching, roughness (IRI), and rutting data revealed that these projects had all performed very well in general at respective 10- to 20-year milestones. No rehabilitation and only one minor maintenance activity has been performed on LA-710, and no maintenance/rehabilitation activity has been performed on the 10-year-old projects. Analysis of the LA-710 and TEH-5 deflection data suggests some densification (not to the extent of crushing) and aging in the asphalt-bound layers but no signs of traffic-induced damage. Laboratory test data on between-wheelpath specimens from the TEH-5 project indicate that the as-built materials in general have better fatigue performance, lower stiffness, and lower permanent deformation performance than the statewide median materials tested during mix design. Given the fact that only minor rutting has been observed in these projects, the as-built materials are believed to be good examples of mixes with balanced performance, with a few exceptions. |
| Keywords: | Engineering, long-life asphalt pavement (LLAP), performance-related specifications (PRS) |
| Date: | 2026–03–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt8b52q3s4 |