bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges and solutions of logistics operators in the last mile of supply chains
Authors: Muharemović Ermin , Kosovac Amel , Begović Muhamed , Šimić Edvin
Published: October 2024

The paper explores the key role of the last mile in the evolution of supply chains, with a focus on identifying challenges and solutions applied in the last phase of delivery. Today's challenges for logistics operators have significantly evolved over the past two decades due to current and growing trends. With the rise of e-commerce and urbanization, the last mile becomes a crucial point of competition, where fast, customized, and sustainable delivery emerges as an imperative for all involved stakeholders. The paper is divided into three parts. The first part refers to the identification of challenges faced by logistics operators in the last phase of the supply chain. The second part of the paper provides an overview of existing solutions and strategies that can be used to respond to challenges in the last mile of delivery. The third part offers case studies that provide a comparative cost analysis using different strategies in the last mile of delivery. Through the analysis of various solutions and strategies in the final stage of the supply chain, different aspects of efficiency and costs are illuminated in various scenarios. Understanding these dynamics is crucial for shaping the future of delivery that is efficient, sustainable, and tailored to the needs of the modern consumer.
Road safety audit from concept to results
Authors: Arampatzis Orestis-Theodoros , Kehagia Fotini
Published: October 2024

The main requirement for the upgrading road infrastructure safety is the implementation of a comprehensive analysis in terms of road safety. Greek legislation (Presidential Decree104/2011) in line with the European Directive 2008/96/EC, as amended by Directive 2019/1936/EC, plans to implement Road Infrastructure Safety Management (RISM) for the road network of Greece. To prevent accidents, one of the primary RISM procedures is the Road Safety Audit (RSA) technique. This paper addresses the RSA findings on a national of 4-lane road network in Greece, as a re-active approach to identifying safety issues and infrastructure deficiencies. The interurban road Thessaloniki - Nea Moudania is part of the A24 motorway, which length is 56 km and practically connects the prefecture of Thessaloniki with the prefecture of Halkidiki. The study was at the framework of a graduate thesis of Civil Engineering Department of the Aristotle University of Greece. Following the audit carried out, it was found that most of the problems relate to passive safety systems, signage, visibility issues, the condition of pavement and the characteristics of junctions.
Study of configuration of overhead contact line imaging device for Shinkansen
Authors: Matsumura Itaru , Yamashita Chikara
Published: October 2024

Overhead contact line (OCL) is installed over long distances, so that a lot of maintenance worker is required for its maintenance. To reduce OCL maintenance works such as walking patrols and close-distance inspections, it is strongly desired to automate part of the inspection of OCL, especially anomaly detection of OCL fittings which are installed in large quantities. To automate OCL inspection, it is efficient to inspect OCL by analysing these anomalies in OCL images obtained from imaging device installed on the running vehicle instead of visual inspection by maintenance workers. In this paper, we proposed an imaging device configuration using two monochrome line scan cameras with tilt-shift lens and near-infrared LED lights to acquire OCL images in Shinkansen speed range up to 360km/h. To enable frequent inspection, the proposed device configuration was considered with mounting on the roof of a commercial train. The imaging range was set to be -400 mm to +400 mm in stagger and 4800 mm to 7000 mm in height from rail level as the installed range of OCL for Shinkansen, taking account into the car-body tilting system. The image obtain frequency of the device was set to the maximum of 40 kHz which corresponded to the resolution of 2.1 mm in the travelling direction at a running speed of 300 km/h. Hence, the device can acquire OCL images with an image quality that enables the auto detection of anomalies of OCL fittings. We prototyped a device according to the proposed configuration to verify its performance in bench tests. As a result, it was confirmed that the proposed device configuration ensured a depth of zone that covered the installed range of OCL. In addition, it was also confirmed that the device could obtain images of a rotating disk simulating 300 km/h running with 2.1 mm resolution and without subject blur.
Study on road visibility in the context of road safety
Authors: Petcu Claudia , Răcănel Carmen , Petcu Mihai Dragos
Published: October 2024

Road safety is a pressing problem in all countries of the world, road accidents, and the main cause of serious injury and loss of human life, constituting a challenge in the field both from a social and economic point of view. The relationship between design geometry and crash rate is complex and not fully understand. Little information is available in the international literature on the relationships between design geometries and the number of road accidents, although it has been clearly demonstrated that very restrictive geometries, such as very short sight distances or tight (small radius) roadway curves, that are in significantly higher accident rates and certain combinations of factors causing unusually serious accidents. Road safety depends on many factors, one of the most important sight distances. The study aims to highlight the factors that contribute to the determination of sight distances, i.e. to increase road safety, given that there are no such studies in Romania. The study is carried out with the help of a specialized calculation software, Civil Site Design, software developed in Australia that allows road designers to work faster and smarter. The Civil Site Design application is developed by Civil Survey Solutions Australia, works on top of BricsCAD, AutoCAD, AutoCAD Civil 3D platforms and offers advanced functionalities for road design at Romanian standards.
Railway corridors in cities as a factor of urban development
Authors: Jurković Željka , Lovoković Danijela , Cingel Ivan
Published: October 2024

The sustainability of urban development is related to the transport system in cities, including railway transport. Intra-city transport infrastructure, including railway, is one of the most important elements of the quality of the urban environment. In this paper, railway traffic corridors are observed through two basic components: the linear space of intra-city railway corridors and the surrounding area of railway stations. The paper presents the basic theoretical and practical principles of reconstruction of railway intra-city corridors and railway stations within cities. Railway corridors have the potential to stop being an obstacle to connecting parts of the city, while railway stations have the potential to become central places of city traffic, accompanying urban functions (commercial, service, public) and identity places of the city. Intra-city railway corridors in Croatian cities are important for the modernization and technical reconstruction of the railway as a transport system, but also as a factor in the urban renewal. The paper examines the reconstruction of the railway within the city of Zagreb, which was technically reconstructed but the urban reconstruction of the intra-city railway corridor was missing. The paper cites the city of Osijek as a positive example of the beginning of the urban renewal of the area around the Osijek railway station. In conclusion, it is pointed out that the reconstruction of the railway in the city should include the urban reconstruction of the area of the railway corridors, not only the technical and safety reconstruction of the transport system, and that the railway stations should once again become places of the city's urbanity.
Crack classification in concrete using parameter- and signal-based acoustic emission analysis
Authors: Tayfur Sena , Alver Ninel
Published: October 2024

Acoustic emission (AE) is one of structural health monitoring techniques providing meaningful information about damages within the materials. To classify crack types in AE analysis, an optimal transition line between shear and tensile cracks has been still demanding. There exist numerous studies investigating this subject in the literature. The researchers have adopted the ratio of RA value and average frequency parameters of the signals for classification; however, it is concluded that the transition line is mostly based on the empirical conditions. In this study, parameter- and signal- based AE analyses were combined for crack classification of damage activities of concrete under flexure. After monitoring damage processes of the concrete simultaneously by AE, spectrum analysis was conducted on the AE signals and their weighted peak frequencies were obtained. By evaluating dominant frequency characteristics of the signals, they were classified as tensile or shear crack and the classification was verified by parameter-based analysis. Afterwards, AE signals were labelled using crack types obtained from signal-based analysis, RA and average frequency parameters were distributed and the optimal transition line was determined.
Utilization of mine overburdened materials in low volume roads subbase/base with coconut coir geotextile reinforcement
Authors: Gouda Jagdish , Dudhabaware Ayush , Reddy Dakka Sitarami , Venkatraman Srinivasan
Published: October 2024

This research investigates the feasibility of incorporating mine-overburdened materials into low-volume road construction, particularly in subbase and base layers, through small-scale laboratory testing. Mine overburdened materials, typically considered as waste, have the potential to serve as cost-effective alternatives in road construction. However, these materials often fail to meet the stipulated criteria of the Ministry of Road Transport and Highways (MoRTH) specifications. The study focuses on enhancing the mechanical properties of the overburdened materials that are obtained to meet the standards. Laboratory experiments, including modified proctor tests and California Bearing Ratio (CBR) testing, were conducted to assess the engineering characteristics of the mine-overburdened materials. The results indicated that, in their natural state, these materials do not conform to MoRTH (2013) standards. The experimental results reveal a notable improvement in the engineering properties of the mine's overburdened materials when combined with coconut coir geotextiles. The modified proctor tests demonstrate enhanced compaction characteristics, while CBR testing indicates 1.84 times improvement when compared with the unreinforced mine overburdened materials. Using coconut coir geotextile effectively improves the suitability of mine overburden materials for low-volume road construction, promoting sustainable and cost-effective practices.
Dynamic behaviour of the sleeper length transition in railway turnouts
Authors: Marangon Francesco , Pospischil Ferdinand
Published: October 2024

Railway turnouts are important components of a railroad network. Compared to a normal track, they are more expensive and have many areas with complex dynamics. One of these areas is the transition from long sleepers to short sleepers at the end of a turnout. The dynamics that arise there affect both the vehicles and the infrastructure. As such, understanding and addressing these dynamics is crucial, as they can lead to increased maintenance needs, a reduced availability and, consequently, higher costs. To better understand the occurring dynamics at this jump in stiffness, the actual reaction of the transition must be recorded. As part of the FFG-Comet project Rail4Future, measurements were performed on a turnout in an Austrian main line to this end. These measurements included recording the vertical sleeper displacements at multiple positions in the transition zone as well as the dynamic axle loads outside of the influenced area. The data was used to study the behaviour of this transition zone, especially looking at influencing factors on track panel twist, such as vehicle type, axle load and travelling speed. These new insights into the transition in sleeper length can be used, among others, in the evaluation of vehicle-based measurements, as the measurement itself is influenced by the vehicle.
IoT-driven track health monitoring for sustainable railway operations
Authors: Sándor Hunor , Szántó Zoltán , Orbán Zsolt
Published: October 2024

The modernization of railway infrastructure maintenance practices demands innovative approaches to ensure safety, optimal performance, and optimized operational costs through the integration of novel technologies. The Internet of Things (IoT) delivers for this domain the innovative cloud- and edge-powered data collection, aggregation and processing which enables the cost effective and performant data-driven maintenance strategy. The traditional approach to track maintenance relies on periodic inspections done with Track Recording Vehicles (TRV). Data collected by TRV measurements offers the most reliable information regarding the track geometry simply because the measurement is done under dynamic load. However, most of the rail network maintenance organizations are facing issues with the limited availability of the TRV. This impacts the condition monitoring schedule and proper maintenance of the track, often effecting speed restrictions to be applied. This paper presents a comprehensive study on the continuous monitoring of railway track conditions using an IoT measurement device that assures non-invasive track monitoring with the possibility to be installed on passenger trains which are transiting the railway network much more frequently than a TRV. Our IoT measurement device captures and transmits critical information related to track geometry (alignment, longitudinal level, cross level, and twist of the track) by analysing the specific motions of the bogies of passenger trains. The collected data is saved and processed in cloud and can be accessed through a centralized monitoring dashboard, providing railway operators with valuable insights to the health of their track infrastructure. Furthermore, this paper explores the possibility of defining degradation models of the track by analysing historical data patterns and predicting potential maintenance needs. The implementation of such predictive maintenance strategies not only improves safety but also optimizes operational costs by reducing the likelihood of unexpected track failures.
Assessing preferences for the introduction of a new tram line on University of Zagreb campus using stated preferences experiment
Authors: Kožul Nikola , Novačko Luka , Babojelić Karlo
Published: October 2024

The development and introduction of sustainable urban transportation systems is crucial in addressing increasing traffic congestion and environmental concerns in the cities. This article aims to assess the potential acceptance and demand for a proposed new tram line in the area of University of Zagreb Campus Borongaj. Using a stated preference survey, a sample of commuters within the area were surveyed to understand their preferences and willingness to use the planned tram line. The survey included questions about travel behavior, transportation modes currently used, and their stated preference for the new tram line in terms of proposed travel time, price, comfort, and access time. The collected data were analyzed using multinomial logit model to estimate relative importance of different factors that affects individuals’ choice and acceptance of the new tram line. Additionally, socio-demographic variables were analyzed to identify variations in preferences among different demographic groups. Results of the experiment will provide valuable insights to urban planners, policy makers, and transportation authorities in their decision-making processes. Understanding the preferences and needs of users of the proposed tram line will assist in designing an efficient and user-friendly transportation system, improving overall accessibility and mobility within the area.
Restructuring model of railways of the Republic of Srpska
Authors: Urumović Siniša , Ilinčić Gordana , Urumović Biljana , Kuravica Danijela
Published: October 2024

Republika Srpska has identified restructuring of the railway sector among top priorities to improve public finance and ensure the provision of high-quality rail services. Modernization of the railway sector was envisaged as the reform of the company in order to operate public rail transport of passengers and goods in accordance with the EU principles and Directives. The objectives of organizational restructuring are to provide the ŽRS with appropriate mechanisms to support their long-term financial sustainability and to align the organizational structure with the railway framework of EU directives and regulations, while creating a clear vision, direction and independence of the role of infrastructure management and operations. The specific objectives of this component include planning and implementation of a new, more commercially driven organizational structure of ŽRS, consisting of corporate core plus two independently managed and separately accounted business divisions, one for infrastructure management and one for transport operations. Within the operations, the accounts will be kept for freight and passenger traffic.
Predictive analytics for enhancing performance and safety in continuously welded rail
Authors: Orbán Zsolt , Mărculescu Laurențiu
Published: October 2024

The modernization of rail infrastructure demands innovative approaches to ensure optimal performance and safety. In present days, railway tracks are increasingly installed with continuous welded rails (CWR) to reduce train vibration and noise. Unfortunately, CWR’s are prone to lateral buckling, which is a rather complex phenomenon that is observed in a wide range of physical circumstances. Numerous factors affect track buckling, but the rail temperature and the stress-free (neutral) temperature of the CWR are two of the most important factors. Rail temperatures are closely related to air temperature, which is constantly increasing due to global warming. The Romanian railway regulations and instructions that are dealing with construction and maintenance works on CWR, define the neutral temperature range between 17 and 27 degrees Celsius for the entire railway network of the country. However, we must bear in mind that Romania, likewise several countries in the EU, has both a quite divers climate and geographical relief. In this condition, the temperature variations can generate excessive thermally induced axial forces, leading in most cases to destabilization or tensile fracture of the CWR track. One of the main concerns of Railway Administrations is to determine the buckling temperature of the CWR in different sections of the railway network. This is not an easy task, due to the several parameters which are affecting the buckling temperature such as: rail’s neutral temperature, misalignment of the rails and ballast resistance. This paper introduces a comprehensive framework for predictive analytics by presenting a model of probabilistic buckling analysis for CWR tracks based on rail temperature predictions using different wayside monitoring equipment. By adopting these models, rail operators will be able to proactively address issues before they escalate, optimize their maintenance schedules, reduce downtimes, and minimize the risk of accidents.
Application of microsimulation modelling in the assessment of urban intersection reconstruction
Authors: Ištoka Otković Irena , Zečević Đuro , Deluka-Tibljaš Aleksandra , Šimunović Mirjana , Šurdonja Sanja
Published: October 2024

Intersections are critical points of the urban transport system according to various criteria such as capacity, safety, economic, ecological, etc. The reconstruction of the intersection affects various spatial and traffic aspects. Hence, the effects of the reconstruction need to be analyzed in the planning phase of design and analysis of alternative solutions. By applying microsimulation traffic modeling, it is possible to analyze the effects of the various solutions on existing and future traffic demand. In this paper, the traffic safety effects of the reconstruction of a selected urban intersection, where different horizontal discontinuities were applied, are analyzed. In addition to the functional indicators (vehicle delays, queue parameters), the effects of the reconstruction of conflict zones were analyzed through dynamic indicators (vehicle speeds of access routes). Vehicle speed has the greatest impact on the outcomes of traffic accidents in human-vehicle interaction. The analyses were done on the intersection located near an elementary school where potential child-vehicle collision can occur. In this paper, the existing intersection and three alternative reconstruction solutions were analyzed, using microsimulation traffic modeling for the measured traffic load and traffic increase of 100%, 150%, and 200%. Speeds on the major street were measured automatically for 24 hours. The morning peak hour, when children go to school, was chosen as relevant, when the traffic count was made for all traffic flows in the intersection by using a video camera. The optimal reconstruction solution was chosen by analyzing selected functional and dynamic indicators with the basic goal of increasing the traffic safety of pedestrian traffic flows.
Inductive railway turnout heating systems – a review of scientific publications
Authors: Heger Julian
Published: October 2024

Electrical heating rods are state of the art heating systems to keep railway turnouts clear from ice and snow. Installation, maintenance and procurement is easy. Operational experience of several decades show good efficacy up to moderate wintry weather conditions. However, the energy efficiency is low. A significant amount of heat does not contribute to snow and ice removal but is transferred directly to the environment. Anthropogenic climate change will most likely lead to less days with snowfall but increased short-term snowfall intensity. Future turnout heating systems therefore would need increased capabilities of snow and ice removal. In contrast, overall energy efficiency must be increased to reduce greenhouse gas emissions, explicitly required by the EU energy efficiency directive. Inductive heating of railway turnouts is considered a potential heating method to achieve higher energy efficiency in railway infrastructure. To obtain a well-founded overview of the current scientific knowledge and for future decision-making, this paper presents a scoping review of scientific publications of the last 14 years about inductive turnout heating systems. Technical design approaches and operating parameters of several inductive heating systems are compared. Expressed drawbacks of inductive heating used in railroad infrastructure and so far unanswered topics regarding electromagnetic exposition and health safety as well as electromagnetic interference are pointed out. Additional investigations need to be carried out before inductive heating can be considered as a preferred future heating method for railway turnouts.
Participation of autonomous vehicles in real-life traffic: an assessment of the behaviour of road users
Authors: Kondratovič Vladislav , Rimkuvienė Jurgita , Čygas Donatas
Published: October 2024

Self-driving vehicles, also known as autonomous vehicles (AVs) are gradually making their way into real-life scenarios. In Lithuania, there has been significant progress in the field of transport, particularly in the development of autonomous car technology within the road transport sector. A legal framework has been established to define the conditions and processes for the participation and testing of AVs in public traffic. However, integrating AVs into real-world environments necessitates a deeper analysis of the changing interactions between autonomous technologies and human-driven vehicles. This is crucial for identifying potential trends and consequences of such interactions. Drivers commonly make various mistakes due to distractions, fatigue, inexperience, and other factors. In traffic scenarios where two or more vehicle units or road users participate, each must consider the others to avoid potentially dangerous situations. In traffic involving AVs, communication with other road users becomes more challenging. This is not only due to the complex technical aspects of autonomous systems but also factors such as the absence of eye contact, which hinders the prediction of the intentions of all road users and the execution of safe manoeuvres on a case-by-case basis. This article explores the interaction between AVs and other road users. It assesses the significance of different infrastructure elements for AVs traffic, which influences the successful integration of AVs into real traffic alongside human-driven vehicles.
Possibility to apply capacity analysis of two-lane roads with passing lane in HCM 7th Edition in Southeast Europe countries
Authors: Lovrić Ivan , Čutura Boris , Maslać Danijela
Published: October 2024

In the analysis of two-lane roads, the passing lane plays a very important role not only in improving the level of service but also in improving safety. This is best shown by a new design of self-explaining roads, or a European implementation of 2+1 roads. The positive effect of improving two-lane roads by passing lanes essentially extends beyond their end. The HCM methodology is mostly used in the region when analysing two-lane roads. The approach has been significantly changed in the seventh edition of the HCM and it cannot be applied in its original form. This article will show how this methodology can be applied under the prevailing road and traffic conditions outside the U.S. environment, especially in countries that do not have a developed capacity analysis methodology. This new methodology again uses density/follower density to determine LOS. The differences in the results of the final improvement will be shown in a particular example by comparison with previous methodologies of HCM and HBS 2015. On the basis of the results obtained, the conclusion will be made on the performance measures that can be applied in our prevailing conditions.
Long-term geometry evaluation in switches and crossings and their mutual comparison
Authors: Raif Lukáš , Hruzíková Miroslava , Plášek Otto , Vyhlídal Michal
Published: October 2024

This paper focuses on the influence of switch and crossing structure types on track settlement. Track settlement is one of the most important parameters influencing track quality and its dynamic behaviour by passing trains. Measurements were taken on switches and crossings with various innovative structural elements installed into the network of the Czech Railways (Správa železnic) since 2010. Using levelling of rail head at regular intervals, the settlement of individual areas of turnouts were evaluated. Conventional turnouts, turnouts with elastic fastening systems, turnouts with under sleeper pads (USP), fixed crossings as well as crossings with movable parts and turnouts designed for high-speed lines, were measured and evaluated. Each turnout area was divided into five specific zones, which were further monitored and compared with each other. The monitored track sections were the area in front of the turnout, the switch panel, the closure panel, the crossing panel and the area behind the turnout. This paper focus on the crossing panel, considered the most dynamically loaded region. The primary goal of the research was to evaluate all measured data over time and compare the rate of settlement of the individual turnout structural type with each other while maintaining the same method and equipment for measurements. Through a long-term comparison, the benefits of individual innovative structural elements have been gained, and the degree of this benefit has been established for each turnout.
Definition of strategically oriented transport users in freight transport at ŽRS
Authors: Gajić Zoran , Radojčić Nada , Božić Mladen , Kovačević Nebojša
Published: October 2024

User of transport services is company or person who, based on contract signed with the carrier, acquires certain rights and assumes certain obligations. The task of the railway company is to meet the needs of service users, the economy and society as a whole, in terms of passenger and cargo transport. If the services and their quality meet the user's demands and the prices are stimulating, it will provide a satisfactory sale of services, as well as the capacity utilization. This paper deals with analytical processing of existing and potentially important users of transport in order to create a basis for consideration of the economic interest of the railways.
Comparison of the military convoys' cross-country mobility estimation results for Croatian conditions
Authors: Gredelj Ivana , Ahac Maja , Ahac Saša
Published: October 2024

The paper investigates the theoretical influence of field conditions and dynamic characteristics of the vehicles on military convoys' cross-country mobility. Convoys' average traveling speed along hypothetical two-way road segments was assessed by the methodologies described in the Transportation Research Boards Highway Capacity Manual 4th and 7th editions. The assumptions on infrastructure and traffic conditions were as follows. The road segment length varied from 0.4 to 6.4 km, its horizontal alignment was linear, and its vertical grade was larger than 6%. As military convoys have a right-of-way, there were no access points, no no-pass zones, and no vehicles in opposing directions along the road segment, and therefore lane and shoulder widths did not influence convoy speed. Average traveling speed on specific upgrades and downgrades was calculated and compared for convoys with 60%, 70%, and 80% of heavy vehicles. The results show there are significant differences in the speed reduction estimated by different methodologies. The results obtained from the Manual 4th edition methodology show that segment length moderately influences speed along specific upgrades and does not influence the speed along downgrades. The Manual 7th edition methodology results were more sensitive to analyzed segment length, grade, base free-flow speed, and convoy composition. The average traveling speed on specific upgrades and downgrades estimated by the Manual 7th edition methodology is on average 10 to 15 km/h lower, respectively. Therefore, it was concluded that this methodology and its results will be further investigated in local conditions through field research for a more comprehensive assessment of its applicability
Urban transport infrastructure and green infrastructure: actions to mitigate climate change
Authors: Pavic Milica , Jokanovic Igor
Published: October 2024

Globally, cities account for 75% of natural resource consumption and 60-80% of greenhouse gas (GHG) emissions. At the same time, 70% of urban areas around the world are already experiencing the consequences of climate change, including extreme flooding, temperatures, and droughts. Within this challenging context, green infrastructure helps to strengthen ecological connectivity through green spaces, encompassing the protection, restoration, and enhancement of biodiversity and ecosystem services. Green infrastructure provides improved resilience, mitigating the effects of extreme temperatures, heavy rainfall, floods, landslides, and droughts. This protection is not only essential for preserving nature, but also holds significant importance for the stability and functionality of the transportation network. The paper presents an analysis of interference between transport and green infrastructure, emphasizes the importance of this bond in struggling with climate change, as well as showing a brief on the approach in the Western Balkans.
Asphalt mechanical performance of rubber bitumen for hot and warm asphalt mixtures
Authors: Almássy Kornél
Published: October 2024

Rubber bitumen asphalt, also known as rubberized asphalt, is a sustainable and environmentally friendly alternative to traditional asphalt mixes. This study aims to provide an in-depth analysis of the use of the Hungarian Oil Company (MOL) development rubber bitumen in hot and warm mix asphalt (WMA). The study examines the effects of rubber bitumen on various properties of WMA, including workability, compaction, durability, and performance. Additionally, the study evaluates the environmental benefits and economic viability of rubber bitumen in WMA through a life cycle assessment and cost analysis. The findings of this study highlight the potential of rubber bitumen in enhancing the sustainability, lower energy emission and performance of warm mix asphalt.
Optimising bridge maintenance: a case study in assessing bridge condition using novel technologies and methods
Authors: Pajan Jurica , Duvnjak Ivan , Goričanec Jurica , Ereiz Suzana
Published: October 2024

Bridges are well known as the most critical parts of infrastructures, serving as vital links for transportation networks. However, ensuring their proper functionality, structural safety, and durability requires careful and timely maintenance and regular assessment of their condition. A large infrastructure and a huge number of objects together with economic constraints make this task exceedingly difficult. The traditional bridge maintenance approach is primarily based on periodic visual inspections that can be accompanied by additional destructive or non-destructive tests. Such practice is well-established and accepted among practitioners, but data about bridge conditions, collected through a time-consuming process may pose challenges in interpretation. In the end, it might not provide a comprehensive picture of a bridge’s overall health. Therefore, advanced methods are now being used to enhance the overall process. They are based on the usage of new technologies such as unmanned aerial vehicles (drones) equipped with high-resolution cameras, light detection and ranging sensors (Lidar), and other sensors embedded within the structure to obtain more detailed information about bridge condition. This information can then be used together with computational methods like finite element modelling to assess bridge conditions and structural performance on a much higher level. This article presents an approach to assess the condition of an existing case study bridge using state-of-the-art technologies and methods. The condition of the bridge is assessed using a 3d model generated from the photos of the bridge acquired by an unmanned aerial vehicle equipped with a high-resolution camera. Captured bridge geometry is subsequently employed to develop a finite element model, serving as a baseline for vibration-based damage detection analysis.
Falling-weight-deflectometer-based structural condition assessment of low-volume road pavements: practices and challenges
Authors: Karbočius Martynas , Vaitkus Audrius
Published: October 2024

Falling weight deflectometer (FWD) is widely used as one of the most reliable and cost-effective methods to assess the bearing capacity of a pavement structure and its separate layers. Although FWD-based bearing capacity measurement and evaluation techniques were fairly well developed over several decades, little attention was paid to roads with low traffic flow. The applicability of existing techniques to evaluate bearing capacity of low-volume road pavements is limited. Furthermore, the results of the analysis may be inconsistent with the complete set of data, which includes visual pavement condition and structure material sampling data. This leads to subjective treatment of research results and the risk of questionable decisions. This article reviews commonly used pavement bearing capacity analysis techniques and presents the practice applied in Lithuania. Case studies on low-volume roads highlight limitations and possible improvements in methodology to optimise the assessment of the pavement condition of low-traffic roads and related decision-making.
Review of low-budget measures for the prevention of traffic accidents at level crossings
Authors: Barić Danijela , Grabušić Silvestar
Published: October 2024

Level crossing (LC), as an intersection of road and railway, is a traffic point with a high risk for the occurrence of traffic accidents. The causes of most traffic accidents on LCs are the result of LC user’s risky behaviour. Accidents happen on both passive and active LCs, indicating that the highest level of safety equipment does not guarantee "Vision 0". Therefore, in the absence of sufficient financial resources for the infrastructure manager for road and railway levelling or LC protection at the highest level, which includes barriers or half-barriers, the so-called low-budget measures are implemented. This paper provides a review of good practice examples of implemented low-budget measures that contributed to accident prevention and increasing safety on LCs. In the literature, accident prevention measures on LCs are usually classified as educational, infrastructural, and technological. In this research, our focus was primarily on measures implemented on road infrastructure. First, we selected recommended measures from projects dedicated to safety on LCs, and then we searched the literature describing practical examples of applied low-budget measures. The collected findings can be recommendations for decision-makers to choose optimal low-budget measures for implementation.
Assessment of lignin as a potential bio-modifier for conventional bitumen
Authors: Kalampokis Stavros , Manthos Evangelos , Matthaiou Georgios
Published: October 2024

The main objective of this study was the investigation of the characteristic properties of lignin-modified bitumen with different lignin contents. Three (3) blends with different lignin contents (5%, 10% and 15% by weight of bitumen) were produced. Characteristic properties such as penetration, ring & ball, elastic recovery, force ductility, dynamic viscosity and storage stability were determined for the reference bitumen and the three lignin blends. Furthermore, the results of the tests were utilized to calculate the Penetration Index (PI), Activation Energy (Ea), Viscosity-Temperature Susceptibility (VTS) Index and Mixing Temperature (Tmixing) along with their respective Pearson’s Correlation Coefficient (PCC), R2 and p-values. The main conclusion was that Kraft lignin powder hardens the conventional bitumen. Specifically, the addition of 15% lignin to the bitumen hardened the blend to such a degree that the bitumen changed category from 50/70 to 35/50 with respect to EN 12591. Additionally, a strong linear statistical correlation was observed between Ea and VTS Index suggesting that these values should be taken into consideration when characterizing the temperature susceptibility of bio-modified bitumen.
Fatigue assessment of an 100 years old riveted truss railway bridge
Authors: Rajchel Mateusz , Siwowski Tomasz
Published: October 2024

Fatigue is one of the most often reasons for failure in existing steel railway bridges, particularly with riveted structure. Therefore fatigue assessment is always the most important part of the complex evaluation of existing steel railway bridges. Furthermore, the reliable fatigue assessment is often decisive in the estimation of the remaining service life of a bridge. The purpose of the presented research is a fatigue assessment of an 100 years old riveted truss railway bridge. The assessment was carried out to decide whether the existing truss superstructure is still suitable for rehabilitation in the frame of the ongoing modernization of the railway line. The fatigue assessment procedure is based on the safe life method in the convention of nominal stresses.
Platform screen doors earthing and bonding strategies for design and maintenance
Authors: Mariscotti Andrea
Published: October 2024

The EN 17168 has finally provided a reference for the electrical design of Platform Screen Doors (or Platform Barrier Systems) for the interface with the station, the rolling stock and the platform, including interaction with passengers. Two main configurations are possible,with PSD potential bonded to the station earth or to the track ( or floating, insulated from both), each with advantages and disadvantages that deserve attention for suitability for construction and maintenance, as well as for a system assurance perspective. The risk assessment and the technical judgment are carried out half formally half recurring to past experience, thus deviating often from a formal system-assurance-oriented approach in favor of clarity and completeness. Issues related to maintenance are discussed considering typical approaches, the most frequent repair and verification operations, and the normal aging of materials and systems. The outcome of the analysis is a preference for the earthed PSD that allows a better control of interfaces and a more durable design.
Reliability comparison of two-point and four-point bending tests for coarse aggregate mixtures
Authors: Veselý Petr , Dašek Ondřej
Published: October 2024

This paper investigates the reliability and comparative performance of two European standardized methods for assessing the stiffness and fatigue characteristics of asphalt mixtures with coarse aggregates up to 32 mm in grain size. European standards currently prescribe many various approaches to testing fatigue properties of asphalt mixtures, mainly two distinct methodologies: the two point bending test and the four point bending test. Despite the availability of both methods, certain laboratories predominantly prefer the two point bending test. The study focuses on a comprehensive set of tests conducted on asphalt mixtures containing coarse aggregates with a maximum grain size of 32 mm, applying both the two point and four point bending tests. The primary objective is to assess the reliability of these methods, particularly in the context of larger aggregate sizes. A crucial consideration arises from the fact that the two point bending test uses smaller specimens, potentially leading to an increased likelihood of test specimen failure in coarse aggregate asphalt mixtures. The experimental approach involves subjecting asphalt specimens to fatigue loading using both testing methods, systematically analysing the resulting data, and comparing the stiffness and fatigue performance outcomes. The findings contribute valuable insights into the appropriateness and reliability of the chosen testing methodologies, aiding practitioners and researchers in making informed decisions regarding the selection of fatigue testing protocols for asphalt mixtures with coarse aggregates.
Investigations of red-coloured speed humps installed across the entire width of the carriageway
Authors: Džambas Tamara , Stančerić Ivica , Dragčević Vesna , Topić Donatela
Published: October 2024

Pedestrians and cyclists are defined as vulnerable road users and are particularly at risk in traffic accidents in urban areas. A common speeding prevention measure used worldwide to protect vulnerable road users and ensure their safety in urban areas is the use of vertical traffic calming devices, i.e. speed humps and speed bumps. This article deals with red-coloured speed humps that are installed across the entire width of the carriageway. The geometric characteristics of such speed humps, the materials from which they are made and the installation and marking procedures are described. The reasons for their increasing use in the installation of new and replacement of existing vertical traffic calming devices in Croatia are also discussed. Finally, a short survey was conducted at two locations in Zagreb, the capital of Croatia, where two different types of these speed humps are installed: the speed hump installed immediately before the crosswalk and the speed hump on which a crosswalk is marked. A total of 60 road users (drivers, pedestrians, and cyclists) were interviewed to find out their opinions and satisfaction with these devices.
Smart tunnel in industry 5.0: improving road tunnel resilience by dynamic risk analysis
Authors: Focaracci Alessandro , Martirano Luigi , Zacchei Francesca
Published: October 2024

Safety in tunnels is being contemplated through a holistic approach due to accidents that occurred through years. Technological innovations have led to the tunnel concept evolution from civil to technological infrastructure, where technology overcomes the limits of the geometric design, increasing its operating capacity. This paper aims to illustrate SCADRA principles (Supervisory Control Acquisition and Dynamic Risk Analysis), developed thanks to EURAM (EUropean Risk Analysis Method) methodology, which assessed the risk of over 600 road tunnel tubes, focusing on the following values: users and managers' needs (Human-centricity), usage of green technologies and application of energy saving strategy (Sustainability), and improvement of tunnels resilience (Resilience). SCADRA is used in monitoring continuously the tunnel state by gathering the safety influence variables and performing a dynamic risk analysis, quantitative and probabilistic, in real-time. The system was installed in three Italian road tunnels, executing over 130,000 instantaneous risk analyses. The applications’ results and the future developments will be presented according to tunnels’ safety improvement, maintenance, and management.
Speed profile calculation with an acceleration model: case study of Zagreb tramway system
Authors: Majstorovic Igor , Ahac Maja , Haladin Ivo
Published: October 2024

Knowledge of the speed profile of electric tramway vehicles is crucial for optimizing tramway traffic management procedures. This includes creating and optimizing timetables, calculating energy consumption, and maintaining rail infrastructure. The speed profile is influenced by many parameters, such as the maximum permitted speed and acceleration of the tram, the distance between stops, and the dwell time. In the past, a simplified model that assumed constant acceleration and deceleration was used to determine the speed profile of tramway vehicles. However, this model can lead to inaccuracies, especially for vehicles with high acceleration or deceleration capabilities. A more accurate approach is to use a model that considers the actual acceleration profile of the train. This can be done using data collected from GPS sensors to track the speed of the train over time. This paper presents a comparative evaluation of three acceleration models: a simple linear model, a linear multi-regime model, and a polynomial model, created from the data collected on the Zagreb tramway network. The GNSS (Global Navigation Satellite System) device was used to collect data on the acceleration and deceleration of the vehicle. Using proposed model to calculate the speed profile and timetable with an acceleration profile has several advantages. Firstly, it can improve the accuracy of the speed profile and timetable, which can lead to higher efficiency and reliability. Secondly, the timetable can be optimised for specific requirements, e.g. to minimise travel time or maximise passenger capacity.