Journal of Road and Traffic Engineering

METHODOLOGICAL FRAMEWORK FOR THE ANALYSIS OF THE COST OF DELAYS IN THE CONSTRUCTION OF MOTORWAYS

Drazenko Glavic — 2026-06-12

Delays in the construction of highway infrastructure are a universal problem and are very common and present in the world. Delays in the construction of highway infrastructure result in increased costs. Most scientific papers and studies deal with the causes of delays, while the costs associated with project delays are very rarely analyzed in the literature. With this in mind, the aim of this paper is to define a methodological framework for the analysis of the costs of delays in road construction. On the basis of a defined, methodological framework for the analysis of the cost of delay, it is possible to define the total cost of delay. The results obtained in this paper can help decision-makers in defining a new policy to reduce delays in road construction in order to reduce project losses and costs.

RELEVANT CHARACTERISTICS OF THERMOSTABLE ASPHALT REINFORCEMENT GRIDS

Dragan Stojnić — 2026-06-17

In the rehabilitation design of flexible pavement with asphalt wearing courseg, one of the potential measures involves the application of thermostable grids for asphalt layer reinforcement. Their use extends the service life of asphalt layers while providing significant economic and environmental benefits. The functional mechanism of these grids is based on a combination of interlock (mechanical adhesion), chemical adhesion, and tensile strength. Numerous technical papers have been published regarding the selection of optimal grid characteristics to maximize their contribution to pavement performance. This paper analyzes the key properties that affect the interaction between the reinforcement grid and the asphalt layer under dynamic loading, as well as relevant laboratory tests - primarily tensile strain elongation (Epsilon 6) and tensile strength reduction after installation. The results of the conducted tests demonstrate measurable performance benefits and provide a reliable assessment behavior of the combined asphalt layer/reinforcement grid system under dynamic loads conditions typical for pavement structures. The analyzed characteristics represent one of the key parameters in the process of rational computing of pavement with the use of reinforcing grids. The conducted analysis may serve as a guideline for designers in selecting an appropriate type of grids for asphalt pavement reinforcement, as well as for investors in defining the terms of reference and requirements in tender documentation.

THE IMPACT OF EXISTING AND PLANNED TRANSPORT INFRASTRUCTURE ON THE SPATIAL DEVELOPMENT OF SLOVENIA: THE CONCEPT OF THE SPATIAL PLAN OF SLOVENIA

Andrej Gulič — 2026-06-17

Transport infrastructure is a key driver of spatial development, settlement patterns, and regional economic dynamics. By determining levels of accessibility and connectivity, transport systems influence the spatial distribution of population, economic activities, and services. This paper examines the impacts of existing and planned transport infrastructure on the future spatial development of Slovenia, with particular attention to settlement structure and regional accessibility. The analysis combines theoretical perspectives from regional development theory, accessibility theory, and land-use transport interaction models with the strategic objectives of the Concept of the Spatial Plan of Slovenia. The study demonstrates how transport infrastructure contributes to the development of a polycentric settlement system, reduces regional disparities in accessibility, and strengthens functional linkages between urban centres. Special attention is devoted to planning concepts such as “60-minute Slovenia,” “30-minute regions,” and “15-minute local centres,” which aim to ensure equitable access to services and employment across the national territory. The results indicate that coordinated spatial and transport planning plays a critical role in achieving balanced territorial development, improving economic competitiveness, and supporting sustainable mobility in Slovenia. This paper aims to examine how existing and planned transport infrastructure will influence Slovenia’s spatial development under the new Concept of the Spatial Plan of Slovenia.

ANALYSIS AND SELECTION OF STONE MASTIC ASPHALT (SMA) MIXTURES IN PAVEMENT SURFACING FOR DIFFERENT TYPES OF ROADS

Dragan Stojnić — 2026-06-17

In the selection of asphalt layers for pavement surfacing, the proper choice of the gradation of the asphalt mixture
and the nominal maximum aggregate size significantly affects the properties of the asphalt layer and its performance in
service. This paper analyses the application of stone mastic asphalt (SMA) mixtures and the criteria for their proper
selection with respect to their position within the pavement structure (wearing and binder course) and the intended use of
the traffic surface (motorways, expressways, urban roads, and airport manoeuvring areas). For the purpose of performance
comparison, laboratory testing was carried out on SMA 8, SMA 11, and SMA 16 mixtures, and the obtained results enable
a reliable assessment of their behaviour under dynamic loading conditions characteristic of pavement structures. The
analysed characteristics represent key parameters for selecting the appropriate type of SMA mixture. The paper's
conclusions may serve as practical guidance for designers in defining the type of SMA to use in pavement surfacing, as
well as for investors when formulating project requirements and conditions in tender documentation.

TUNNEL CONSTRUCTION THROUGH HIGHLY KARSTIFIED LIMESTONE WITH LARGE CAVITIES: CASE OF VJETERNIK TUNNEL

Dušan Panić — 2026-06-17

The construction of the Vjeternik tunnel, located on the Smokovac–Mateševo section in Montenegro, posed
significant engineering challenges due to its alignment through highly karstified limestone formations with large cavities.
During excavation, a massive cavern exceeding 30 meters in vertical extent was encountered, requiring urgent design
modifications and the implementation of specialized stabilization measures. These included steel arches, drainage
systems, and concrete slabs, with additional reinforcement applied to the inner lining. The paper highlights shortcomings
in prior geological investigations and emphasizes the need for more extensive engineering-geological and geophysical
surveys in future tunneling projects. It underscores the importance of experienced supervision and adaptive design
strategies. Although focused on tunneling, this paper is equally relevant to decision-makers responsible for funding
engineering-geological investigations.

CONSTRUCTION AND MAINTENANCE OF STATE ROADS ON THE PEŠTER PLATEAU

Mirsada Uglić — 2026-06-17

Until five years ago, more than 50% of the state roads on the Pester Plateau were covered with macadam. On the Zaljevska River in Razdaginja, at the time of high water level, you crossed over a wooden bridge, probably the only one of its kind on state roads in Serbia. In winter, road maintenance could not be imagined without the use of bulldozers, loaders or graders. Macadam did not allow the use of other machinery. In the last five years, all state roads in Pester have been asphalted, the possibility of using modern cleaning devices in winter conditions (snow plows, plows, spreaders...) has been opened, cross-border cooperation has been made possible at two locations and conditions have been created for the development of tourism and the progress of the village.

CHALLENGES IN THE MANAGEMENT OF PUBLIC ROADS IN THE CITY OF BELGRADE

Saša Cvjetić — 2026-06-17

The management of public urban roads in Belgrade takes place under complex urban conditions characterized by high traffic density, intensive urban development, and frequent interventions on existing infrastructure. As the manager of a network exceeding 4,400 km of city streets and municipal roads, PE “Roads of Belgrade” faces the challenge of maintaining functionality, quality, and safety of roadways while minimizing disruptions to the city’s daily operations. This paper analyzes the specific challenges of carrying out works on public urban roads under conditions of heavy traffic, such as limited construction deadlines, phased project implementation, the need for night-time operations, the impossibility of complete traffic closure, as well as the necessity for continuous coordination with other infrastructure systems. Through practical examples and an analysis of the current condition of the city road network, possibilities for improving construction technologies and the application of modern asphalt mixtures are considered, which can better respond to increasingly demanding urban traffic conditions. The aim of this paper is to highlight the need for establishing an integrated approach to the management and maintenance of urban roads, which would ensure long-term quality, safety, and functionality of the streets of Belgrade.

NUMERICAL EVALUATION OF ROAD EMBANKMENT SETTLEMENTS

Nikola Obradović — 2026-06-17

Settlement of embankments represents a major serviceability concern in the design and operation of road infrastructure. Reliable settlement prediction is essential to estimate pavement deformations and reduce maintenance interventions during the service life of the road. This paper presents a numerical assessment of settlements of road embankments founded on soft overconsolidated soils. The analysis is performed using the finite element method and an advanced constitutive model formulated within the critical state soil mechanics framework. Two documented embankments with available field measurements are analysed to evaluate the applicability of the adopted numerical approach. The results indicate that reliable estimation of embankment settlements can be achieved using numerical analyses combined with constitutive models requiring a limited number of parameters obtained from standard laboratory testing.

OBJECTIVES, CHALLENGES AND SOLUTIONS FOR DIGITAL PAVEMENT MANAGEMENT OF TRANSPORT INFRASTRUCTURE

Daniel Hilpert — 2026-06-17

The sustainable preservation of road infrastructure requires a consistent, data-driven pavement management approach integrating technical, economic, and organizational aspects. This paper discusses key objectives, challenges, and solutions for digital pavement management at network level. Major challenges include heterogeneous data sources, long-term data availability, evolving regulations, and the demand for transparent and reproducible decision-making. The presented approach combines high-resolution pavement condition data, standardized referencing systems, comprehensive quality assurance, and performance-based prediction models within a unified digital framework. By systematically transforming raw measurement data into validated condition indicators and maintenance strategies, digital pavement management enables preventive maintenance, optimized allocation of financial resources, and improved acceptance among decision-makers and road users. Modern web-based pavement management systems support strategic, tactical, and operational planning while ensuring data consistency and adaptability over the full lifecycle of pavement assets.

ASPHALT REINFORCEMENT AND EFFECTS AFTER 16 YEARS SINCE INSTALLATION IN BELGRADE

Marija Bakrac — 2026-06-17

The application of polyester geogrids during pavement rehabilitation represents a well-known solution proven through decades of practice worldwide. In such design solutions, the geogrid is used as asphalt reinforcement to delay the reflection of cracks from old flexible, semi-rigid or rigid layers of pavement structure into new asphalt layers. In this way, the durability of new asphalt layers is extended by up to 3 times, which brings significant direct and indirect economic and ecological benefits.
The exceptional impact of PET geogrid, with tensile strength of 50kN/m, very thin non-woven PP geotextile and coating with high bitumen content, will be presented through an example of its application on a part of the former highwaythrough Belgrade, the section in front of Belgrade Arena. The pavement rehabilitation on this section was carried out in the summer of 2010, and its condition after almost 16 years of use under heavy traffic load is still very good. For 13 years of use, this section functioned, until October 2023, as part of the E 75 highway, while it now represents a city thoroughfare. The success of PET geogrid application on this section, expressed through the longevity of the rehabilitation carried out 16 years ago, is even more significant when considering the condition of the section at that time, caused by cracks that occurred in the cement stabilization layer.

IMPORTANT TECHNICAL PARAMETERS RELATED TO THE QUALITY OF THE ROAD, THROUGH THE PRISM OF THE APPLICATION OF ASPHALT REINFORCEMENT GRIDS FOR ASPHALT, PRODUCED FROM DIFFERENT RAW MATERIALS

Marija Bakrač — 2026-06-18

A summary of experience in the application of Asphalt Reinforcement Grids, produced from different raw materials. Clear guidelines of the necessary technical parameters can be drawn, regarding the technical characteristics of the product itself depending on the raw material from which it was produced, as well as through the test results of independent laboratories connected to institutes and faculties. As a result, we will receive unequivocal guidelines for the application and achievement of the best results in the system of
Asphalt Reinforcement Grids, which connect the extension of the life of the pavement structure, by obtaining excellent adhesion of the two asphalt layers, which are located below and above the Asphalt Reinforcement Grids. The presented results refer to the installation of Asphalt Reinforcement Grids on the existing / new leveling layer as well as to the installation on fine and rough milled surface.

MANAGING AND MAINTAINING STORMWATER DRAINAGE SYSTEM OF THE REVITALISED GAZELA BRIDGE OVER THE SAVA RIVER IN BELGRADE

Aleksandar Đukić — 2026-06-18

The paper presents the design of the drainage system of the Gazela Bridge over the Sava River in Belgrade during its reconstruction and subsequent experiences related to the assessment of the system’s efficiency. The bridge was originally built without a drainage system with direct discharge of polluted runoff into the river and the surrounding terrain, which posed a risk to the structure and the quality of surface and groundwater in the protected water supply zone. The reconstruction of the bridge also included the construction of a system for efficient water collection and conveyance, combined with treatment, retention and controlled infiltration. The retention-infiltration facility including the first flush treatment enables partial reuse of stormwater for irrigation and watering, indirectly recharging groundwater. On the other hand, dynamic testing of the bridge structure under load and subsequent deformation modelling showed that bridge deflections can significantly affect the efficiency of drainage by changing the pipeline slope and thus the flow conditions, with an increased risk of sediment deposition in the pipes. A bridge inspection revealed degradation of the drainage system, highlighting the importance of maintenance to ensure the functionality of the system, especially to prevent clogging of culverts and pipes. The paper highlights the need for an integrated design approach that considers traffic, hydraulic, structural and environmental aspects, while the presented results indicate a practical path for sustainable stormwater management on bridges, especially in sensitive urban and hydrogeological environments.

METHODS FOR ASSESSING THE CONDITIONS OF PAVEMENT WITH AN EXAMPLE OF ASSESSMENT IN NOVI SAD

Milan Marinković — 2026-06-18

This paper presents methods for assessing the condition of flexible pavement structures. Over time, pavement structures are damaged due to traffic loads, climatic factors, maintenance frequency and material quality. In order to assess the current condition of a pavement structure, it is necessary to perform surveys or appropriate measurements. There are non-destructive and destructive methods for determining the condition of pavements. This paper presents 4 methodologies for collecting data by visual inspection and the method of processing the obtained results. The mentioned methodologies are: Pavement Condition Index (PCI), Strategic Highway Research Program (SHRP), Pavement Condition Rating (PCR), Present Serviceability Rating (PSR). For each of the methodologies, rating scales are listed and what each rating represents. Also, the types of distresses for each methodology are shown. In addition, an example of assessing the condition of pavements in Novi Sad according to the Pavement Condition Index methodology is shown.

THE ROLE OF THE MULTIMODAL PHYSICAL AND VIRTUAL TRAFFIC SIMULATOR IN SCIENTIFIC RESEARCH

Marko Vukojević — 2026-06-18

Understanding interactions among different road users is essential for developing effective multimodal transportation policies. Driving, pedestrian, and bicycle simulators are widely used in transportation research to evaluate engineering applications and test human behavior under controlled and repeatable conditions. However, these simulators are typically employed in isolation, and integrated multimodal platforms that allow drivers, bicyclists, and pedestrians to interact within a virtual environment are limited. This paper presents a synthesis of research conducted at the Pittsburgh Intelligent Transportation Systems Laboratory, demonstrating how an integrated multimodal human-in-the-loop traffic simulation framework can support diverse transportation research objectives, including advancements in traffic theory, insights into bicyclist behavior, novel approaches to traffic conflict analysis, and emerging applications in energy research through distributed testing capabilities.

ENHANCING THE ROAD SAFETY INSPECTION PROCESS THROUGH THE DEVELOPMENT OF A SOFTWARE SOLUTION

Kosta Jovanov — 2026-06-18

This paper examines the process of conducting road safety inspections, focusing on the technical and organisational shortcomings that appear during field investigations, office-based data processing, georeferencing, documenting observed infrastructure deficiencies, and preparing the final report. Based on an examination of the existing common workflow and the limitations of the most commonly used software tools, it was discovered that, in practice, the procedure relies on the fragmented use of multiple solutions that were not specifically designed for the needs of road safety inspections, complicating the process and slowing down data analysis and report preparation. Based on the identified technical requirements, a specialised software solution was developed that integrates video playback, GPS and cartographic data processing, station analysis, documenting deficiencies, the use of checklists, and the preparation of outputs for final report. Validation of the developed tool was accomplished through preliminary beta testing of the application in office-based information processing, with the goal of determining its practical usability and contribution to more efficient recording and systematisation of findings. Initial results show that this approach improves the efficiency, accuracy, and consistency of road safety inspections, particularly under resource-constrained conditions such as those faced by local governments and LMICs.

DETERMINATION OF SAFETY CRITERIA AND PROCEDURES FOR ROUTING STATE ROADS THROUGH SETTLEMENTS

Marija Dotto — 2026-06-18

State roads represent the backbone of transport connectivity and economic development of the Republic of Serbia; however, routing them through populated areas requires particularly careful planning and management. Such practice leads to an increased safety risk for all road users, deterioration of residents’ quality of life, and conflicts between the needs of the local community and the requirements for efficient transit traffic flow. Although the existing laws and by-laws define the differences between driving conditions on roads outside settlements and within settlements, as well as the application of appropriate traffic signage, the lack of clearly defined criteria and procedures results in inconsistent solutions and complicates the role of local self-government units in the process of planning and managing road infrastructure. This paper examines the safety criteria that must be met in order for a state road to be routed through a settlement. Particular attention is devoted to the analysis of the existing regulatory framework, which formally enables the implementation of the prescribed measures, but whose practical application remains insufficiently effective and often inconsistent.The paper proposes the establishment of a clear and transparent decision-making procedure regarding the alignment of state roads through settlements. Such a procedure would include defined safety requirements, measurable criteria, and the active involvement of local self-government units in the planning and decision-making process, with the aim of improving road safety and promoting sustainable urban development. The objective of the document is to ensure consistent application of regulations, enhance the safety of all road users, reduce the negative impacts of transit traffic on populated areas, and enable the alignment of road infrastructure development with the principles of sustainable and safe urban planning.

ANALYSIS OF FACTORS INFLUENCING THE UNDERSTANDING OF TRAFFIC SIGNS

Anđela Novaković — 2026-06-18

Traffic signs represent the primary means of informing all road users and are essential for the efficient and safe functioning of traffic, both on road and urban street networks. Although they are designed to be clear and unambiguous, traffic signs are often misinterpreted. The aim of this paper is to identify, based on previous research and international experience, the factors influencing the understanding of traffic signs, with particular emphasis on their design, standardization, user characteristics, and the role of the visual environment. Special attention is also given to the consequences of inconsistent national standards and their connection to frequent errors in sign interpretation. The paper further highlights the need for empirical research that would contribute to the development of guidelines for improving the comprehension of traffic signs depending on relevant influencing factors.

RESEARCH ON URBAN ROAD TRAFFIC SAFETY RISK IDENTIFICATION METHOD BASED ON ABNORMAL DRIVING BEHAVIOR

Fu Yuan — 2026-06-18

To address the issues of ambiguity and subjectivity in current road traffic safety risk identification, this paper proposes a quantitative evaluation method for urban road traffic safety risk based on abnormal driving behavior data. Firstly, abnormal driving behaviors (such as speeding, sudden acceleration, sudden deceleration, sharp lane changes, and sharp turns) are identified on road segments using GPS trajectory data, and an indicator system of abnormal driving behavior rates is constructed. Based on this, the AHP-EW integrated weighting method is employed to determine the weight of each behavior on safety risk. Combined with the fuzzy comprehensive evaluation method, a road traffic safety risk assessment model is established to achieve quantitative risk grading. Validation using actual road segments in a city in Shandong Province demonstrates that this method can effectively identify high-risk road sections, providing traffic management departments with accurate and real-time data support for road network safety risk identification and control.

SPATIAL COVERAGE ANALYSIS BY EMERGENCY SERVICES: A CASE STUDY OF THE ROAD NETWORK IN THE BAČKA DISTRICT

Boris Antić — 2026-06-18

The efficiency of emergency service response directly depends on the spatial organization and functionality of the road network, as the time required to reach the incident location represents a key factor in reducing the consequences of fires, traffic accidents, and other emergency occurences. This paper analyzes the spatial accessibility of roads to fire and rescue units of the Emergency management sector within the Bačka District (data obtained from the official website of the Ministry of the Interior of the Republic of Serbia – Emergency management sector), with particular emphasis on the influence of the road network structure and connectivity on population coverage. Using QGIS, a network-based analysis of emergency vehicle movement along the existing road network was conducted for time thresholds of 5, 10, 15, and 20 minutes. The share of the population that can be served within each defined response time was estimated. The results show that approximately 37% of the population is covered within the first 5 minutes, increasing to 61%, 77%, and 89% within 20 minutes. The findings highlight the importance of the spatial distribution of units in relation to the hierarchy and capacity of roads, as well as the need to improve transport infrastructure and optimize base locations in order to reduce response times. The study provides a foundation for integrating transport planning with risk management systems, aiming to enhance traffic safety and improve the efficiency of emergency interventions on the road network.

EVALUATING THE EFFECTS OF SIGNALIZED INTERSECTIONS ON THE ROUNDABOUT SAFETY AND CAPACITY: A CASE STUDY FROM OSIJEK

Irena Ištoka Otković — 2026-06-18

Urban traffic management is a critical component of sustainable city planning, directly influencing mobility, safety, and environmental impact. In many urban environments, roundabouts and signalised intersections are fundamental elements of traffic control, each with distinct operational characteristics and implications for traffic flow. The interplay between these two types of intersections is particularly significant in densely populated areas where the proximity of different types of intersections can have compounding effects on traffic behaviour. Signalised intersections and roundabouts are prominent features of Osijek’s traffic network, each playing a vital role in managing the flow of vehicles and pedestrians. This study analyzed the safety and operational indicators of a single roundabout and a roundabout in a corridor between two traffic signalized intersections. The safety features were analyzed using the Microsimulation Traffic Model (VISSIM) and Surrogate Safety Assessment Model (SSAM). The analysis of operational indicators included field measurements and microsimulation traffic modeling with a default and calibrated model.

ANALYSIS OF THE EFFECTS OF PREVENTIVE RADAR SPEED ENFORCEMENT DEVICES ON SPEED LIMIT COMPLIANCE ON A SECTION OF THE M-1 STATE ROAD

Vladimir Ilić — 2026-06-18

Exceeding the prescribed speed limit represents one of the most common forms of unlawful driver behavior in urban areas. In order to reduce the risk of traffic accidents caused by inappropriate speed, various traffic calming measures and techniques are applied. This paper examines the effect of preventive radar speed measurement devices on compliance with vehicle speed limits. The research was conducted in the Municipality of Bar, on the M-1 state road, along the Bar–Ulcinj section, which passes through a populated area, both before and after their installation. Reference data were obtained from measurements conducted in June 2024, when only rumble strips were implemented at the study location. On that occasion, a total of 472 vehicles were recorded using aerial drone footage. The results indicate that rumble strips reduce vehicle speed by 4.93 km/h; however, 79.2% of drivers still exceed the prescribed speed limit. Therefore, a comparative analysis was performed following the installation of preventive radar speed measurement devices, and their effects in combination with rumble strips were evaluated.

THE IMPACT OF HORIZONTAL CURVES ON THE OCCURRENCE OF TRAFFIC ACCIDENTS USING THE METHOD OF INDEPENDENT ROAD IMPACT ASSESSMENT

David Rilak — 2026-06-18

Traffic accidents significantly hinder the economic progress and development of a country by requiring the allocation of substantial resources for mitigating their consequences. Traffic accidents are predominantly caused by errors, inattention, improper actions, and other mistakes made by drivers, i.e., the human factor within the H-V-R-E system (Human, Vehicle, Road, Environment). In addition to the influence of the human factor, the road factor also plays a significant role, both in the occurrence of traffic accidents and in the severity of their consequences. Recognizing the road as one of the key contributing factors to traffic accidents, increasing attention has been devoted to improving road infrastructure and roadside environment through the development and implementation of the concepts of self-explaining and forgiving roads. Particularly critical road segments are changes in road alignment, such as horizontal and vertical curves, which require increased driver attention and specific road design and roadside treatment. The aim of this paper is to identify the main deficiencies and influential road-related factors contributing to the occurrence of traffic accidents in horizontal curves, through the application of an independent road impact assessment tool in cases of fatal traffic accidents.

ANALYSIS OF THE IMPACT OF WEATHER CONDITIONS ON TRAFFIC FLOW PARAMETERS ON THE "9. JANUAR" MOTORWAY

Vladimir Gatarić — 2026-06-18

Traffic flow parameters are subject to the influence of many factors. The analysis of these factors on certain parts of individual road categories helps to understand the structure and characteristics of traffic flow on different road categories. Among other things, weather conditions are those that can significantly affect the flow and speed of vehicles. This paper analyzes the impact of weather conditions on certain parameters of traffic flow on the motorway. The research was conducted on the "9. januar" motorway, which connects the E-661 Gradiška-Banja Luka motorway and the section of the Johovac-Rudanka motorway on the Pan-European Corridor 5c through Republika Srpska. The aim of the paper was to show whether and how weather conditions affect the flow and speed of vehicles on the motorway.

EVALUATION OF SIDEWALK ADAPTATION TO PEDESTRIAN NEEDS – A CASE STUDY OF BELGRADE’S CENTRAL URBAN AREA

Jelica Komarica — 2026-06-18

By promoting the use of more environmentally friendly modes of movement, modern cities increasingly recognize walking as a form of mobility that, in addition to reducing traffic congestion, encourages healthier habits, economic equality and social interaction. However, despite its key role in the development of a sustainable transport system, walking often depends on the spatial-functional characteristics of the designed street network, including infrastructural barriers that not only affect the width and overall usability of sidewalks, but also the satisfaction of pedestrians when moving. Bearing that in mind, this paper aims to indicate the extent to which pedestrian sidewalks are adapted to pedestrians from the aspect of designing and satisfying their needs within the central city zone of Belgrade. Relying on the results of field and survey research, an assessment of the level of pedestrian satisfaction was made, which depends on the presence of physical obstacles and the adaptability of the sidewalk to different groups of users. By presenting a useful basis, this paper contributes to the development of a methodological framework and provides support to decision makers in understanding the problem and proposing appropriate design solutions.

IMPACT OF TRAFFIC FLOW CONDITIONS ON VEHICLE SPEEDS IN ETC LANES - A CASE STUDY OF A TOLL PLAZA IN SERBIA

Miloš Tubić — 2026-06-18

Barrier-based ETC (Electronic Toll Collection) systems enable automated toll payment, eliminating the need for stopping, thereby allowing higher travel speeds and increasing lane capacity compared to conventional manual toll collection systems. In Serbia, a significant increase in the number of ETC tag users has been recorded in recent years, highlighting the importance of improving and efficiently implementing electronic toll collection systems. This paper analyzes vehicle speeds in barrier-based ETC lanes as a function of vehicle category and traffic flow conditions. An empirical study was conducted at the mainline toll plaza Stara Pazova on the A1 motorway, where vehicle speeds were measured within the influence area of ETC lanes. The objective of the study is to examine the existence of statistically significant differences in mean speeds between vehicle categories and different traffic flow conditions, as well as to evaluate the credibility of the posted speed limit within the ETC lane influence zone. The results indicate that traffic flow conditions have a significant impact on vehicle speeds when passing through ETC lanes, while differences between vehicle categories decrease with increasing levels of saturation. The findings contribute to a better understanding of the operational characteristics of barrier-based ETC lanes and may serve as a basis for improving toll plaza management, design parameters, and capacity estimation models in toll station areas.

SECOND GENERATION OF SUSTAINABLE URBAN MOBILITY PLANS IN THE REPUBLIC OF SERBIA

Vladimir Đorić — 2026-06-18

Comprehensive traffic analyses and transport studies are currently not required as a mandatory component of spatial and urban planning documentation in the Republic of Serbia. Since 2016, Sustainable Urban Mobility Plans (SUMPs) have been incorporated into planning practice, most frequently initiated or supported by European development institutions in cooperation with local self-governments. Cities in Serbia that have adopted a SUMP have improved opportunities to compete for EU funds intended for “green” infrastructure, as the SUMP serves as evidence that the city has a clear vision of sustainable development and is committed to enhancing the quality of urban life. The City of Valjevo is the first city in the Republic of Serbia to undertake and complete a revision of its SUMP, thereby reaffirming its long-term commitment to the continuous and strategic advancement of the urban mobility system. The revision was implemented within the framework of the CityWalk 2.0 project, financed through the Interreg Danube Region Programme. This paper presents the lessons learned during the revision process of the Sustainable Urban Mobility Plan. Particular emphasis is placed on methodological improvements and procedural modifications introduced during the planning process, specifically in the following domains: research and analysis of mobility patterns, development of networks for sustainable modes of transport, measures aimed at influencing user behavior, and the enhancement of conditions for mobility. Clearly defined and operationalized activities are systematized within the implementation action plan, which constitutes the principal instrument for executing the planned measures and achieving the defined objectives.

ANALYSIS OF THE OPERATIONAL EFFICIENCY OF BORDER CROSSINGS AS A FUNCTION OF VARIABLE DESIGN HOURLY VOLUMES

Milica Tubić — 2026-06-18

The characteristics of temporal variability of traffic flow constitute a fundamental basis for the planning, design, and operation of road infrastructure systems. The determination of the design hourly volume represents a critical input for decision-making processes related to infrastructure provision, the dimensioning of roadway design elements, as well as the definition of traffic management and operational control strategies. Highway border crossings represent critical nodes within the transport network, essential for ensuring the continuity and reliability of international traffic flows. Their dimensioning has a pronounced impact on overall system performance, particularly in terms of capacity utilization and the achieved level of service (LOS) along the corresponding highway section. This paper presents a comprehensive analysis of the influence of variable design hourly volume values on the dimensioning of border crossings, taking into account the temporal non-uniformity of traffic demand throughout the annual cycle. Special emphasis is placed on the sensitivity of capacity and performance indicators to fluctuations in peak demand conditions. The analysis is supported by a case study of the Preševo Border Crossing on the E-75 highway, including detailed capacity and level of service assessments. Furthermore, the paper identifies and evaluates a set of operational measures aimed at improving the efficiency of border crossing operations and enhancing the overall level of service of the analyzed system.

MULTI-CRITERIA DECISION-MAKING MODEL OF COMPARATIVE EVALUATING TRAFFIC SAFETY INDICATORS

Brankica Bubić — 2026-06-18

Traffic safety is one of the key issues of public safety, and the analysis of indicators of risky behaviour of traffic participants enables the identification of priority areas for preventive action. This paper analyzes traffic safety indicators at the level of police administrations in the Republic of Srpska, with the aim of determining their importance and ranking the observed police administrations according to the level of security. An integrated MCDM model was applied to classify police administrations based on traffic safety indicators. The SWARA method was used to determine the weight of the criteria, through which the importance of traffic safety indicators is analyzed, while the MARCOS method was used for the final ranking of police administrations in relation to the defined indicators. The results of the research enabled the identification of the most significant factors that affect traffic safety, as well as the selection of police departments with the most favourable and unfavourable values of the observed indicators. By simulating the input values, 42 new scenarios were formed. The results obtained can serve as a basis for the creation of targeted preventive measures and the improvement of traffic safety strategies, with a special focus on the indicators that have the greatest impact on the final ranking.

2+1 ROADS AS A MEASURE FOR TRAFFIC IMPROVEMENT: SWEDISH EXPERIENCE AND POSSIBILITIES FOR IMPLEMENTATION IN SERBIA

Sara Krsmanovic — 2026-06-18

This paper analyzes the concept of 2+1 roads as a contemporary road design solution that provides a compromise between conventional two-lane roads and motorways. Particular attention is given to the safety and functional characteristics of these roads, as well as to their economic feasibility. Increasing traffic volumes on two-lane roads may lead to a higher risk of head-on collisions, indicating the need to improve their safety. The 2+1 road concept is based on the alternating provision of an additional overtaking lane and the physical separation of opposing traffic flows. Experience from Sweden, Germany, and other countries indicates that 2+1 roads are a cost-effective alternative that provides a high level of safety, comparable to motorways, while requiring significantly lower construction costs. The implementation of this concept could significantly improve traffic safety and traffic flow efficiency in Serbia, particularly on road sections with moderate to high traffic volumes.

METHODS FOR IMPROVING TRAFFIC SAFETY IN HORIZONTAL CURVES WITH CRITICAL RADIUS

Sara Krsmanović — 2026-06-18

This paper analyzes traffic safety in horizontal curves with critical radii, which represent one of the most hazardous elements of road infrastructure. Key risk factors are examined, including small curve radii, inconsistency between design and operating speeds, reduced pavement friction, and unfavorable roadside conditions. A set of measures for improving traffic safety is proposed, including low-cost treatments such as enhanced signage and visibility, as well as engineering measures involving improvements to road geometry and pavement condition. The paper highlights the importance of timely identification of high-risk locations and the implementation of appropriate countermeasures in order to reduce the number of traffic accidents and improve overall traffic safety.

PARKING MANAGEMENT IN THE CENTRAL ZONE OF BELGRADE: ASSESSING EFFICIENCY IN THE CONTEXT OF SUSTAINABILITY

Vladimir Čuljković — 2026-06-18

The modern concept of parking management, based on the transport and parking demand management, has developed as a consequence of adopting the sustainable transport system concept. In this context, parking in the central area of Belgrade has been managed for more than 20 years. Although continuous monitoring of state and adjustment of measures implemented are the only guarantees of effective management, according to the authors’ knowledge, the state of parking in this area has not been systematically analyzed for many years. Despite this, parking measures – including paking regime zone boundaries and regulatory attributes, the tariff system, infrastructure, and other elements – have been modified on several occasions, apparently in an ad hoc manner, that is, without a comprehensive analysis that should precede their definition. Furthermore, changes outside the parking subsystem that directly affect it must also be considered, such as a sudden increase in car ownership levels, modifications in dynamic traffic regimes, changes in the operation and tariff system of public transport, and similar factors. All of the above were the reasons behind writing this paper, which aims, based on a limited example from the inner central area of Belgrade, to assess the current parking state, identify key shortcomings in its management, and propose guidelines that would contribute to achieving the strategic objectives of parking management within the broader framework of sustainable development.

PARKING MANAGEMENT IN OUR CITIES AND ITS IMPACT ON URBAN MOBILITY

Jelena Simićević — 2026-06-18

In addition to its primary role of addressing parking issues, parking management has recently been recognized as a powerful instrument for managing urban mobility and achieving the goals of a sustainable transport system, primarily by reducing the car use. Nevertheless, in our experience, these potentials have not been adequately utilized in most of our cities (parking is either unmanaged or managed poorly), which often results in parking remaining a dominant traffic-related problem with pronounced negative impacts on traffic flow, safety, and overall quality of life in cities. This paper, based on a meta-analysis of parking performance indicators conducted on a limited sample of six cities, assesses the effectiveness of parking policy in achieving its direct and general objectives.

UPGRADE OF POLYMER MODIFIED BITUMEN FOR DURABLE ASPHALT PAVEMENT: A NEW APPROACH

Olivier Fleischel — 2026-06-18

Asphalt pavements face higher axle loads and rising temperatures, requiring improved binders. A first study in 2024 compared AC22 BASE mixtures using PmB 45/80‑65 and B50/70 modified with 3% of an isocyanate reactive additive (ISO P101). Both met moisture resistance; the isocyanate-based mix had slightly lower rut depth and substantially higher high‑temperature stiffness while maintaining comparable low‑temperature stiffness. Fatigue tests favored PmB in lab indirect‑tension, though isocyanate’s higher stiffness may reduce structural strains in pavements. Building on this, hybrid mix designs combining SBS and isocyanate chemistry were developed. Rheological tests (BTSV, MSCR, elastic recovery) and mix trials showed that adding ISO P101 to commercial PmB increases high‑temperature stiffness and rutting resistance while preserving low‑temperature behavior, with field trials demonstrating workability, storage stability and compatibility with up to 50% of Reclaimed Asphalt. These results support reactive isocyanate modifiers as a practical route to more durable and perpetual pavements.

A MULTI-HAZARD AND SOCIO-ECONOMIC CRITICALITY ASSESSMENT OF THE SERBIAN ROAD NETWORK: SUPPORTING CLIMATE RESILIENCE AND INFRASTRUCTURE MANAGEMENT

Elco Koks — 2026-06-18

Climate change is increasingly disrupting transport systems through a combination of extreme weather events and long-term environmental changes. In addition to physical damage, disruptions to road networks can significantly affect access to essential services and the functioning of critical socio-economic systems. This paper presents an integrated methodology for assessing the climate and functional criticality of the Serbian road network, developed to support infrastructure resilience and asset management. The approach combines multi-hazard analysis—including floods, landslides, snowdrifts, and increasing precipitation under climate change with network performance and socio-economic indicators, such as accessibility to healthcare, emergency services, and key transport nodes.A GIS-based framework is used to identify road segments that are both exposed to climate hazards and critical for maintaining connectivity and service accessibility. Due to data sensitivity, the paper focuses on the methodological approach and its application, while results are presented at an aggregated level.The proposed framework provides a practical tool for risk-informed decision-making, supporting the prioritization of investments, maintenance planning, and the development of climate adaptation and crisis management strategies in the transport sector.

INTEGRATED ANALYSIS OF INTERACTIONS BETWEEN ROAD INFRASTRUCTURE AND CLIMATE CHANGE

Marina Milenković — 2026-06-18

Road transport constitutes one of the most significant sources of greenhouse gas (GHG) emissions, thereby contributing to global climate change. At the same time, road infrastructure is highly vulnerable to the impacts of climate change, which result in an increased frequency of damage to road assets. These processes lead to higher maintenance costs and impose additional challenges for road management, ultimately exerting a negative impact on traffic efficiency and safety. In the contemporary scientific literature, increasing attention is devoted to the development of adaptation and mitigation strategies aimed at both reducing emissions throughout the road life cycle and enhancing the resilience of road infrastructure under changing climatic conditions. The objective of this paper is to analyze the bidirectional interaction between road infrastructure and climate change by examining GHG emissions across different phases of the road life cycle, as well as the effects of climatic factors on the functioning of the road network. The paper provides a critical review of contemporary innovative measures applied in international practice and discusses their applicability and implementation potential in the Republic of Serbia.

APPLICATION OF ITS, AI AND DIGITAL TWINS IN THE MANAGEMENT AND MAINTENANCE OF THE ROAD NETWORK

Osman Lindov — 2026-06-18

The transport system faces growing challenges in maintaining road infrastructure due to network ageing, increased traffic loads, limited financial resources, and climate impacts. Traditional maintenance approaches, based on periodic inspections and reactive interventions, are increasingly becoming insufficient to meet the requirements of efficiency, safety, and sustainability. Digitalisation through ITS, IoT, AI, and digital twins offers solutions to modernise road management by enabling data-driven operations, supporting real-time decision-making, and improving predictive maintenance planning. Artificial intelligence (AI) is increasingly transforming the planning, construction, operation, and maintenance of road infrastructure. This paper analyses the role of these technologies in road network monitoring, planning, and maintenance, with a focus on integrating ITS data with Road Asset Management Systems (RAMS), applying edge computing, and using AI models for distress detection and degradation forecasting. In particular, for countries with less developed road infrastructure, the paper discusses key implementation challenges, including data availability and quality, institutional readiness, costs, and cybersecurity considerations. Finally, the paper synthesises the main benefits and limitations and proposes future research directions as well as a phased implementation approach towards resilient and sustainable road infrastructure.

APPLICATION OF ARTIFICIAL INTELLIGENCE IN THE ROAD SECTOR - BETWEEN ENGINEERING SUPPORT, ACCURACY AND THE ILLUSION OF OMNIPOTENCE

Milica Pavić — 2026-06-18

The application of artificial intelligence in the road sector is increasingly presented as a crucial step toward enhancing precision, efficiency, and objectivity in engineering decision-making. However, the growing reliance on algorithmic models raises important questions: does it, in practice, provide genuine support to engineers, or does it create an illusion of precision based on limited and insufficiently reliable data? In this context, a dilemma arises: can artificial intelligence be applied as a powerful tool for solving engineering problems, or should it primarily remain a support for engineers rather than a replacement for specialized knowledge and professional judgment? The paper provides a critical review of the role of artificial intelligence in the planning, design, and maintenance of roads, with a special focus on potentials and limitations of contemporary artificial intelligence solutions.

DIGITAL PRODUCT AND MATERIAL PASSPORTS FOR BETTER MANAGEMENT OF MATERIAL FLOWS IN ROAD CONSTRUCTION AND MAINTENANCE

Jan Prah — 2026-06-18

One of the main challenges in road construction and maintenance is ensuring traceability and transparency in managing large quantities of excavated soil and stone. In Slovenia, around 7 million tons of such materials are produced annually. They are often reused on-site or backfilled, yet still treated as waste, without considering their chemical and geotechnical properties or potential value. The new EU Construction Products Regulation (EC 3110/2024) introduces digital product passports to improve transparency and traceability of material properties. Although excavated soil and stone are not clearly defined as construction products under this regulation, applying its principles is increasingly important due to the large volumes involved. This research addresses digital product passport requirements and presents the development of digital material passport platforms for excavated soil and stone within the LIFE IP RESTART project. It explores pathways based on material status, such as waste, by-product, or construction product, supporting more efficient resource use in line with circular economy principles.

EXPLORATION OF INTELLIGENT TECHNOLOGIES FOR SMART EXPRESSWAY ELECTROMECHANICAL SYSTEMS

Luo Weimin — 2026-06-18

With the rapid development of intelligent transportation systems, smart expressways demand higher reliability, integration, and intelligence of electromechanical (EM) systems. However, existing EM systems often suffer from fragmented architectures, limited data utilization, and low intelligence in operation and maintenance (O&M). To address these issues, this paper proposes a methodology-oriented framework for the intelligent upgrading of smart expressway EM systems. The framework integrates condition-based monitoring, a layered intelligent management platform, and a data-driven O&M mechanism. Multi-source operational data are utilized to enable real-time equipment monitoring, fault prediction, and predictive maintenance. A centralized data architecture and QR code–based field operations are introduced to enhance data traceability and maintenance efficiency. The proposed approach improves system reliability, maintainability, and operational efficiency, providing a scalable solution for smart expressway EM systems.

DYNAMIC OVERTAKING BAN SYSTEM FOR HEAVY VEHICLES

Stamenka Stanković — 2026-06-18

A Dynamic Overtaking Ban System for Heavy Goods Vehicles represents a traffic management measure that enables the overtaking regime to be adapted to prevailing traffic flow conditions. Unlike permanent bans, this system is activated only during periods when traffic flow conditions indicate a higher likelihood of traffic flow disturbances caused by overtaking maneuvers of heavy vehicles. This paper presents the operational logic of the dynamic overtaking ban system, with particular emphasis on the criteria for its application, such as traffic volume, the share of heavy vehicles, and roadway longitudinal grade. The application of the defined logic is tested on sections of the Serbian motorway network, with the aim of estimating the number of hours per year during which the system would be active. The obtained results provide insight into the justification for introducing a dynamic overtaking ban system and identify motorway sections where this measure could have the greatest positive impact on traffic flow efficiency and stability.

TRAFFIC SIGN TAXONOMIES IN COOPERATIVE, CONNECTED, AND AUTOMATED MOBILITY ENVIRONMENTS

Miroslav Petrović — 2026-06-18

The progressive deployment of automated driving and connected vehicle technologies within modern transportation systems has intensified the need for consistent and machine-interpretable representations of roadside traffic signage. Within the framework of Cooperative, Connected, and Automated Mobility (CCAM) and its implementation through Cooperative Intelligent Transport Systems (C-ITS), traffic signage functions not only as a physical roadside infrastructure element but also as a structured information source supporting infrastructure–vehicle interaction. Advancement of vehicle automation questions adequacy of existing conventional traffic sign taxonomies and classification schemes. This narrative review focuses on taxonomies related to roadside traffic signage in the context of automated driving and connected vehicles. It synthesizes existing approaches to traffic sign classification, semantic structuring, and functional categorization as discussed across scientific, industrial, and regulatory literature over the past decade. Based on review findings, areas of convergence and divergence among proposed traffic signage taxonomies, as well as conceptual gaps affecting interoperability between vehicle systems and roadside infrastructure, are presented. The analysis indicates that, while technological capabilities for automated and connected mobility continue to evolve, the development of harmonized and future-oriented traffic signage taxonomies remains fragmented. The paper outlines current research directions and highlights open issues that may point the way of evolution of classification frameworks for traffic signage toward unification within cooperative and automated transportation systems.

IMPACT OF IFC EVOLUTION ON BIM IMPLEMENTATION AND DATA EXCHANGE STANDARDIZATION IN INFRASTRUCTURE PROJECTS

Nikola Knežević — 2026-06-18

The development and application of Building Information Modeling (BIM) in infrastructure projects were long limited by the lack of open and neutral data exchange standards. Industry Foundation Classes (IFC), a key openBIM standard, began its development with a focus on vertical construction, but its application later expanded to the field of infrastructure projects. This paper analyzes the evolution of the IFC schema, with a special focus on the transition from the limitations of the IFC 2x3 version to the extensions introduced in IFC 4.3, as well as the conceptual directions of the development of IFC 5.0. Early implementations based on IFC 2x3 were problematic for infrastructure projects. Since the schema did not contain native infrastructure entities, there was a loss of semantic precision in the models with limited possibilities for automated processing. The paper further discusses how IFC 4.3 improved the application of BIM in infrastructure projects by introducing native support for infrastructure entities. Through the analysis of this evolution, the paper provides insight into how improvements to the IFC standard contribute to a more stable and wider acceptance of the openBIM approach in large-scale infrastructure projects.

HOT MIX ASPHALT RECYCLING AT HIGH PERCENTAGES: PRACTICE OF OPTIMIZATION AND USE OF REJUVENATORS IN SERBIA AND CZECH REPUBLIC

Shahin Eskandarsefat — 2026-06-18

Asphalt recycling, whether hot, warm, or cold, has proven to be the most sustainable, efficient, and readily applicable technology for a wide range of paving applications. In response to this, numerous technical specifications and standards have been developed in recent years to facilitate the incorporation of reclaimed asphalt (RA) into new asphalt mixtures, in some cases even removing limits on the allowable recycling content. In Europe, Italy and Serbia are pioneers in this field, as their regulations define minimum RA contents for new asphalt production and mandate the use of rejuvenators. This paper investigates commonly applied protocols for rejuvenator optimization and presents two successful case studies from the Czech Republic and Serbia, where asphalt mixtures containing 50% and 40% RA, respectively, were produced using a vegetal-based rejuvenator. The results indicate that, in addition to bitumen-scale testing, whether conventional or advanced, a minimum set of mixture-scale performance tests is essential to ensure the satisfactory in-situ performance of asphalt mixtures with high RA contents.

WASTE POLYCARBONATE DERIVED PYROLYTIC OIL AS POTENTIAL BITUMEN REJUVENATOR

Primož Pavšič — 2026-06-18

Increasing the use of reclaimed asphalt pavement (RAP) is a key objective in sustainable pavement engineering; however, high RAP contents often lead to performance degradation due to the aged and brittle binder. Rejuvenators are therefore required in the production of new asphalt mixes with high RAP content to restore binder properties. Meanwhile, incineration remains a common end-of-life option for plastic waste, which conflicts with zero-waste and carbon neutrality principles. Pyrolysis offers a sustainable alternative to incineration by a thermal conversion of plastic waste into oils that can act as bitumen rejuvenators, enabling the use of higher RAP content in new asphalt mix production. This study investigates pyrolytic oil derived from waste polycarbonate as a rejuvenator for aged bitumen. The experimental programme includes oil characterization, compatibility evaluation, and assessment of its effects on the mechanical, rheological, and chemical properties of aged binder. Results demonstrate that polycarbonate-derived pyrolytic oil is a promising rejuvenator for aged bitumen, enabling the useful utilization of waste polycarbonate and the use of higher RAP content in new asphalt mix production, thus supporting circular economy goals and plastic waste reduction.

THE IMPACT OF LINEAR INFRASTRUCTURE DEVELOPMENT ON THE SPREAD OF JAPANESE KNOTWEED (REYNOUTRIA SPP.) IN SERBIA

Jovo Pokrajac — 2026-06-18

Invasive plant species represent an increasing threat to biodiversity in riparian ecosystems, and the development of road infrastructure facilitates their spread. Japanese knotweed (Reynoutria spp.) forms dense monocultures that suppress native vegetation and destabilize riverbanks. This study examines the distribution, ecology, and management effectiveness of populations of this species within road‑construction zones in Serbia, based on monitoring results and digital mapping, comparing them with findings from international studies. It was determined that construction activities significantly influence the spread of Japanese knotweed, with increased activity intensity coinciding with the emergence of new populations and the re‑establishment of previously removed ones. Treated locations showed a substantial reduction in populations and prevention of further spread compared to untreated sites, confirming that linear infrastructure development increases the risk of invasive species expansion and that timely and long‑term application of control measures is crucial for effective management.

SPATIAL VARIABILITY OF TRAFFIC NOISE IN URBAN AREAS – A CASE STUDY OF A SEGMENT OF BELGRADE’S TRAFFIC NETWORK

Milena Stamenković — 2026-06-18

Traffic noise represents one of the most prominent forms od environmental pollution in urban areas and poses a significant challenge for sustainable urban development, particularly due to its negative impact on the physical and psychological health of the population. This study analyzes traffic noise through a case study of selected sections of the traffic network in the city of Belgrade. The aim of the research is to determine the intensity of traffic noise at several characteristic locations and to identify traffic-related factors contributing to its occurrence. The research encompasses noise measurements at locations with diverse functional and spatial characteristics, along with an analysis of the impact of road classification, traffic flow intensity, presence of public transport and other relevant factors. Comparative analysis of the obtained results allows for the assessment of the spatial variability of traffic noise in relation to the selected indicators. Based on the results of the research, measures are proposed to reduce the negative impact of traffic noise, in accordance with the principles of sustainable development, environmental protection and the improvement of urban life quality.

NEW SUSTAINABLE MODULAR AND CERTIFIED ROCKFALL PROTECTION SYSTEMS

Roberto Luis — 2026-06-18

The transition to modular, certified rockfall protection systems represents a natural evolution in flexible barrier engineering. Rather than refining isolated parts, the approach reframes how systems are designed, manufactured, and installed to satisfy current technical, logistical, and environmental requirements. Through modularization, Geobrugg consolidates structural elements that previously evolved separately—post heads, post bases, brake elements, and base plates—thereby simplifying engineering, reducing part diversity, and streamlining logistics without compromising dynamic performance. From an environmental perspective, component standardization reduces embodied carbon, transport‑related emissions, and waste, which is material given that Scope 3 accounts for more than 97% of the Group’s footprint. Field deployment (e.g., Genestoso, Asturias) shows faster installation and fewer on‑site errors, while full compatibility with EOTA‑ETA, CE Marking, FOEN, and the Geobrugg 2025 test protocol has been kept. Overall, the modular strategy strengthens sustainability, manufacturing efficiency, and safety, and supports circular‑economy aims.

IMPACT OF ROAD INFRASTRUCTURE ON THE ENVIRONMENT – UNDERGROUND AND SURFACE WATER

Sanja Fric — 2026-06-18

It is undeniable that the development of road infrastructure brings with it numerous benefits, but it is also impossible to avoid numerous negative impacts on the environment in general. Within this paper, an analysis of the impact of the road infrastructure on underground and surface water will be given. The analyzed influences mean the influences from the road in general, from the applied type of pavement structure, the way of road maintenance, but also the conditions present in the traffic flow. The paper will also show the method of transport of pollutants that wash off the pavement, through underground and surface waters, reach the plant and animal world, and even the population in general. After identifying individual critical situations, measures will be given for reducing negative impacts through the planning of specific drainage systems, methods of surface and underground drainage, as well as methods of filtration of waste water originating from road surface runoff.

COMMERCIAL EXPLOITATION OF HIGHWAYS AND ENVIRONMENTAL EFFECTS: CASE STUDY MILOŠ VELIKI

Marija Mladenović — 2026-06-18

This study examines the distribution of traffic between the “Miloš Veliki” motorway and the alternative route, the “Ibar Highway,” following the introduction of toll charges. The main objective is to determine whether the introduction of tolls influenced drivers’ route choices, increased traffic volumes on the Ibar Highway, and consequently affected the level of harmful gas emissions due to more frequent braking and stopping. The analysis covers the period before and after the motorway was opened to traffic (2018–2024). The research is based on official statistics on traffic volumes, including the number of vehicles by vehicle type and road category (motorway or alternative route), as well as the total distance traveled on specific road sections in the Republic of Serbia. In addition, the COPERT methodology was applied to assign emission factors, enabling the estimation of harmful gas emissions by vehicle category (passenger cars, light-, medium-, and heavy-duty vehicles, and buses) and by road type. The study was conducted using descriptive statistics and correlation analysis in the SPSS statistical software package. The findings indicate a redistribution of traffic between the motorway and the alternative route after the introduction of tolls, with increased traffic load observed on the Ibar Highway. However, in relative terms, the growth rate of motorway usage was higher than that of the alternative route. The results also show that pollution levels are higher on the alternative route and confirm a statistically significant relationship between the number of vehicles and the estimated volume of harmful gas emissions on the observed road sections.