National Road Network Research Articles

Internalizing External Accident Costs in Safety Investment Evaluation Using Cost–Benefit Analysis

The primary objectives of transportation system development in European countries include improving transport efficiency, enhancing national economic competitiveness, and promoting sustainable mobility. A key aspect of achieving these goals is the evaluation of transport externalities, particularly external accident costs, which is critical for ensuring the economic and social sustainability of road transport development. This study comprehensively evaluates external road accident costs and proposes an innovative approach to internalizing these costs through a cost–benefit analysis (CBA). By integrating these external costs into CBA, policymakers can better understand the societal impact of road safety investments, allowing for more informed decisions regarding measures to reduce road accidents and fatalities. This paper also explores the role of specific safety investments, such as installing vehicle restrain systems (VRS), buffers, and terminals on the national road network, as well as installing speed cameras, in reducing accidents and mitigating external costs. The findings highlight road safety measures’ importance in enhancing economic efficiency and social well-being, providing a solid foundation for the sustainable and efficient development of transportation systems.

Management Model Using Standardized Contracts and BIM Tools for the Optimization of PPP Projects in Peru

Public–private partnerships (PPPs) are contractual schemes that have relative success in Latin America due to their configuration, where the spirit of the contract lies in an appropriate distribution of risks. This is both the most important and fundamental aspect of this contractual scheme but also the most complex, as it is the main cause of contract modifications (addenda) in countries across the region. In this context, different concessionary contractual frameworks for PPPs on the national road network of Peru were evaluated, revealing common failure indicators that lead to contract modifications within the first six years of the concession. This study offers the development of a management model that includes the good practices of contractual management of NEC4 Option F and the application of BIM information management processes, optimizing the management of infrastructure through emerging technologies of information management supported by agile contractual schemes.

Emission inventory of IVOCs from diesel engine emissions in China based on real-world measured data

Intermediate volatility organic compounds (IVOCs), recognized as significant precursors of secondary organic aerosols, play a pivotal role in environmental pollution. This study utilized measured real-world emission factors to construct an inventory of IVOC emissions from diesel engines and to analyze their spatial distribution across China in 2022. Furthermore, the emission inventory derived from this approach was compared with that obtained through the IVOC/primary organic aerosol (POA) ratio method. The following findings were observed: (1) In 2022, the total IVOC emissions from diesel engines in China amounted to approximately 430 Gg, surpassing those emitted by gasoline engines and residential solid fuel combustion. Specifically, the IVOC emissions attributed to on-road diesel vehicles, inland vessels, agricultural machinery, and non-road construction machinery were recorded at 377, 39.3, 10.4 and 3 Gg, respectively. (2) In terms of geographical distribution in 2022, IVOC emissions from diesel engines were predominantly concentrated in Eastern, Southern and Northern China; on-road diesel vehicle emissions were primarily located within logistics hubs or regions characterized by extensive national and arterial road networks; while non-road construction and agricultural machinery emissions were largely confined to Eastern and Central China. Emissions from inland vessels exhibited a more distinct regional pattern concentrated mainly within the Yangtze River Delta, Pearl River Delta, and Bohai Rim areas. (3) A comparative analysis between the inventory established using real-world measured emission factors and that derived via IVOC/POA ratios indicated that the latter methodology may have overestimated emissions associated with inland vessels and non-road construction machinery. Moving forward, reducing IVOC emissions from diesel engines is crucial for enhancing air quality and safeguarding human health-particularly concerning heavy-duty vehicles, light-duty vehicles, and inland vessels.

Mapping Geospatial AI Flood Risk in National Road Networks

Previous studies have utilized machine learning algorithms that incorporate topographic and geological characteristics to model flood susceptibility, resulting in comprehensive flood maps. This study introduces an innovative integration of geospatial artificial intelligence for hazard mapping to assess flood risks on road networks within Portuguese municipalities. Additionally, it incorporates OpenStreetMap’s road network data to study vulnerability, offering a descriptive statistical interpretation. Through spatial overlay techniques, road segments are evaluated for flood risk based on their proximity to identified hazard zones. This method facilitates the detailed mapping of flood-impacted road networks, providing essential insights for infrastructure planning, emergency preparedness, and mitigation strategies. The study emphasizes the importance of integrating geospatial analysis tools with open data to enhance the resilience of critical infrastructure against natural hazards. The resulting maps are instrumental for understanding the impact of floods on transportation infrastructures and aiding informed decision-making for policymakers, the insurance industry, and road infrastructure asset managers.

Top causes of road traffic accidents in Romania

Abstract Road accidents worldwide impose a significant burden on national budgets, particularly affecting the least developed countries. According to the latest WHO “Global Status Report on Road Safety 2023,” road fatalities are the leading cause of death among young people aged 5 to 29. Among the European Union countries, Romania has the highest mortality rate. Between 2011 and 2021, approximately 2.8% to 1.1% of Romania’s GDP represented the social costs caused by road accidents. Statistical analysis of serious road accidents in Romania during this period reveals five main causes responsible for at least 50% of the total deaths recorded on the national public road network. The most significant cause is “speed not adapted to road conditions,” accounting for approximately 19% of the total. A road accident occurs due to the action or interaction of three determining factors: human, vehicle, and road (road environment). In most cases, the blame for road accidents is attributed to human error or behaviour. This conclusion is often influenced by data collection methods that do not consider all the influences of road infrastructure on the accident’s dynamics. A closer analysis shows that road infrastructure deficiencies often influence or cause road accidents, highlighting the importance of continuous evaluation and improvement of infrastructure to reduce accident risk. The implementation of Directive 2008/96/EC on road infrastructure safety management has prompted authorities to pay particular attention to infrastructure deficiencies in fatal accidents. During 2018-2021, following road safety inspections, auditors provided police and road administrators with detailed reports on deficiencies that caused or favored fatal accidents. Processing and analysing these reports can form the basis for developing a statistical model that provides a unified approach to road infrastructure deficiencies. This model can set up best practices for road safety, contributing to the uniform treatment of infrastructure problems found by auditors. With the transposition of Directive (EU) 2019/1936, which amends Directive 2008/96/EC, through Romanian Government Ordinance no. 3/2022, an innovative approach to managing road infrastructure deficiencies has been introduced. At the EU level, emphasis is placed on finding main road sections with low safety levels. Specific inspections are directed towards road sections with multiple risks, and remedial measures will focus on cost-effective solutions to enhance safety. Continuous evaluation and improvement of road infrastructure are crucial for reducing accident risk. By addressing deficiencies contributing to serious accidents, authorities can create safer road environments. This proactive approach involves detailed inspections and thorough data analysis to find and rectify potential hazards. The goal is to set up a system that not only responds to accidents but also prevents them by mitigating infrastructure risks. In conclusion, road safety management needs a multi-faceted approach that integrates human, vehicle, and road factors. By implementing directives and conducting rigorous inspections, authorities can significantly reduce road accidents. The development of a statistical model from inspection data will systematically address deficiencies, leading to safer roads and reduced fatalities, highlighting road safety as a public health issue.

A preliminary investigation of the small rockfall triggering conditions along a road network in Slovenia

AbstractRockfalls are among the natural hazards that endanger infrastructure, cause major economic disruptions, and threaten human lives. These phenomena result from long-term geological processes such as tectonic rock deformation or weathering, but the actual rockfall itself occurs suddenly, usually without warning. The triggering mechanisms are complex and difficult to trace. In this study, we investigated the triggering mechanisms of more than 2100 small rockfalls that occurred in 2021 in Slovenia, Europe, along the 51,000 km long national road network. We analyzed their spatial and temporal characteristics, as well as the triggering mechanisms of their occurrence, based on different weather scenarios. Multiple data mining methods were used to investigate triggering conditions, and scenario analyses were used to understand the triggering mechanisms. Most small rockfalls in 2021 were recorded in winter and spring at a density of 1 rockfall per 10 km2. The results show that winter weather conditions have the greatest potential for triggering small rockfalls in Slovenia, both in terms of spatial extent and frequency of triggering weather conditions. The analysis showed that summer storms are an important but indeterminant factor for the occurrence of small rockfalls. Among the scenarios tested, the winter scenario, which includes a combination of antecedent precipitation, snowmelt, and freeze‒thaw cycles a few days before the event, was able to predict 72% of the events in the colder season.

An Integrated Infrastructure Resilience Approach, from the Geotechnical Asset to the Transport Network

The main objective of this work is to present a comprehensive and integrated methodology to enhance the resilience of transportation critical infrastructure (TCI), focusing on the interplay between geotechnical assets and the transport network. Societies are greatly dependent on transport infrastructure systems, and as the mobility of passengers and the transport of freight is continuously growing, a disruption due to natural or man-made hazards creates significant impacts and dysfunctionalities on their operation and necessitates response measures to minimize vulnerability and ensure continuous functionality and robustness through resilience. Therefore, resilience quantification allows the design of ad hoc operation action plans before, during, and after a disruption, considering the dynamics of societal, ecological, and technological (SET) environments. The current work focuses on resilience quantification methodologies for TCIs and on the influence of single geotechnical asset (i.e., slope failure) resilience capacity on the overall system (i.e., national road network) resilience. Two case studies of unexpected transport network disruptions that took place in Greece are presented, and resilience metrics and performance indicators are applied to quantify the influence of the recovery stage.

Mapping Road Surface Type of Kenya Using OpenStreetMap and High-resolution Google Satellite Imagery

Identifying road surface types (paved or unpaved) can ensure road vehicle safety, reduce energy consumption, and promote economic development. Existing studies identified road surface types by using sensors mounted on mobile devices and high-resolution satellite images that are not openly accessible, which makes it difficult to apply them to large-scale (e.g., national or regional) study areas. Addressing this issue, this study developed a dataset of road surface types (paved and unpaved) for the national road network of Kenya, containing 1,267,818 road segments classified as paved or unpaved. To accomplish this, this study proposes a method that integrates crowdsourced geographic data (OpenStreetMap) and Google satellite imagery to identify road surface types. The accuracy, recall, and F1 score of the method were all above 0.94, validating the effectiveness of the method. The data sources of the method are freely available, and the method may be applied to other countries and regions. The dataset developed based on the method can provide data support and decision support for local governments to improve road infrastructure.

Applying Digital Images to Identify Pavement Damage in Support of The Road Infrastructure Development Program

Road damage can cause discomfort while driving and even lead to accidents. According to the National Road Network Condition Map Data in 2017, the level of severe and minor road damage in the East Java region had reached 288 kilometers. Based on this data, periodic road condition assessments and maintenance are essential to minimize damage. Road maintenance efforts are crucial to support road infrastructure development programs. The initial step in road maintenance is to identify road damage, determining the necessary actions to be taken. In this research, road pavement damage identification is carried out using the Yolov5, Yolov6, and Yolov7 methods. Test results indicate that the Yolov5 method performed the best with a validation mAP (mean Average Precision) score of 42%, a Precision value of 0.544, and a Recall value of 0.453. These scores indicate that the accuracy of road pavement damage detection using the YOLO algorithm for depression, corrugation, potholes, and alligator cracking is at its maximum level.

Vulnerability Analysis of a National Road Network: The Case of Mexico

Vulnerability Analysis of a National Road Network: The Case of Mexico

Fatigue vulnerability assessment of a steel arch bridge using the probabilistic weibull model and considering its remaining service life under localized corrosion effects

This study attempts to obtain the approximate fatigue vulnerability of a steel arch bridge from the Colombian national road network. It establishes the interaction between the demand and the available capacity through the Weibull probability equation, and an AASHTO remaining-time equation indicated in (FHWA, 2015). However, the available capacity in terms of the S-N curve obtained from available international references was modified to account for the effects of corrosion present in elements and/or joints in the bridge. The load demand was modeled as the controlled action of the fatigue truck reported in AASHTO, which was systematically located on a structural model represented by Shell and Frame type finite elements, which represented the information available in drawings (in the current Colombian bridge management system), and the one obtained from structural survey activities. The structural model was further calibrated by a parametric study on the modulus of elasticity of steel, which included the minimization of the error difference in the vertical deflections of a bridge load test, keeping the magnitude within the expected ranges established in a protocol. Such reports of actual deflections were achieved using distance meters at important points of the bridge. This model allowed for estimating the magnitude of stresses in the structural elements of the bridge, especially in an area of interest for the study where chemical and physical elements of structural deficiency were determined. The results show an inverse relationship between the probability of failure and remaining service life. The effect of corrosion on the remaining capacity and the probability of failure of the structural elements is clear.

Analysis of National Road Network Connectivity in Bali Province

Bali Province has an area of 5,636.66 km2 or 0.29% of the area of the Unitary State of the Republic of Indonesia. Transportation in the Province of Bali is quite unique because the Province of Bali is a connecting road between the islands of Java and Nusa Tenggara and there is almost no public transportation, this causes transportation in the Province of Bali to be quite busy. Bali Province consists of 57 Districts. Transportation in the Province of Bali is the lifeblood and an important part in terms of supporting development that has economic, social and strategic values which are expected to be able to provide services that benefit the wider community. In addition, transportation also greatly influences the direction of development of the Province of Bali in the future, if there are good transportation facilities and infrastructure between sub-districts, development will be faster and easier to carry out. The literature study used in the connectivity analysis in this study used the literature from Dr. Jean-Paul Rodrigue in his book which discusses Transportation and Accessibility. In the book Rodrigue (2020) mentions Accessibility is a key element in transportation geography and geography in general because it is a direct expression of mobility in terms of people, goods or information.

Analisis Karakteristik Lalu Lintas Terhadap Tingkat Pelayanan Jalan pada Jalan Komodo, Ruteng, Kabupaten Manggarai

Komodo Street is a national road network that connects the regencies of Manggarai and West Manggarai. Along the Komodo Street there are several shopping centers, restaurants and houses of residents who do not have adequate parking space. The existence of pedestrians crossing and the activity of vehicles going in and out of the road affect the level of service. The purpose of this study is to determine the quantity of traffic flow, capacity, and level of service on Komodo Street. The method used in this study is the quantitative analysis based on the PKJI 2014. The analysis of the value of the maximum traffic flow at Point 1 yielded a maximum of 1.103 light vehicle units/hour and a minimum of 519 light vehicle units/hour. At Point 2, the maximum traffic flow value is 1.085 light vehicle units/hour, while the minimum value is 568 light vehicle units/hour. At Point 3, the maximum traffic flow value is 1.077 light vehicle units/hour and the minimum is 558 light vehicle units/hour. At Point 4, the maximum traffic flow value is 1.068 light vehicle units/hour and the minimum is 612 light vehicle units/hour. The maximum capacity value for Point 1 is 2.105 light vehicle units/hour, while the minimum capacity value is 2.061 light vehicle units/hour. The maximum capacity value for Point 2 is 2.105 light vehicle units/hour, and the minimum capacity value is 1.953 light vehicle units/hour. The capacity value for Points 3 and 4 is 2.105 light vehicle units/hour. The level of service values for all points vary at any time, namely B and C.

The Economic Factor as a Key in Planning Activities of the National Road Network

Transport has a key role in economic and social development. It generates economic growth by increasing access to health, education, and other national and regional public services. On one hand, investment in the transport sector boosts economic growth by increasing the return on private investment. On the other hand, the improvement of the transport service helps to reduce the prices of resources and thus - to reduce the production costs, to increase the possibilities of access to different markets. An important problem in defining the need for the construction of transport infrastructure objects is consideration of the economic factor of the projects. It is necessary for making decisions on the implementation of transport policy at the national and international level. Bringing out the economic factor as a key factor in the planning of activities on the national road network has a wide public significance, this necessitates the improvement of coordination in terms of its implementation.

Strategic development of the national road network

Strategically developed transport infrastructure is a basic prerequisite for efficient, effective, and sustainable transport. The transport infrastructure is essential for economic growth, for the mobility of labor resources, for the supply of transport services and for the competitiveness of the bulgarian economy. A major problem identified in relation to the characteristics and qualities of the infrastructure along the main routes is the lack of continuous, consistent, and permanent transport networks to ensure fast and safe movement over longer distances. The development of the national road network must follow the principles of continuity and synergy with the national and European strategic documents. The main strategic priorities in the development of transport are effective maintenance and modernization of the transport infrastructure, as well as increasing the security and safety of the transport system.

Experiences and practices from application of rockfall remedial works at MKD national road network

Rockfalls, landslides and floods continue to have a growing share in the overall damages and losses, influencing considerably the national budget. Recent experiences and practices related to application of stabilisation measures and remediation of rockfall zones along MKD national road network are presented in the article. Analyses are based on case histories where the prognosis of geotechnical conditions is a key element in definition of remedial measures for rock slopes. Some issues related with Consequence Class, as suggested in Eurocode 7 202x, and the concepts of Acceptable Level of Risk are presented. Proposals in definition of Acceptable Level of Risk, through combining Probability of Failure, Reliability Index and Consequence Classes, are given in the article. These findings can help in development and/or improvement of rockfall, landslide and flood risk management strategies.

Determination of road surface correction factors for CNOSSOS-EU in Ireland

Transport Infrastructure Ireland (TII) is a state agency in the Republic of Ireland. The primary function of TII is to provide an integrated approach to the future development and operation of the national roads network and light rail infrastructure throughout Ireland. TII are designated as the Noise Mapping Body (NMB) responsible for the development of strategic noise maps for all national roads carrying in excess of 3 million vehicles a year. Directive 2002/49/EC (commonly referred to as the Environment Noise Directive, 'the END') relates to the assessment and management of environmental noise. It is the main instrument of the European Union (EU) to quantify noise pollution levels, and trigger action within both Member States and at EU level. The END has the aim of establishing a common approach to the management of noise within the EU. Commission Directive (EU) 2015/996 established the common noise assessment methodology for Europe (CNOSSOS-EU). The CNOSSOS-EU road traffic noise emission model calculates rolling noise for different vehicle categories as a function of speed and frequency. The emission is initially calculated under reference conditions, then corrected for differing situations. For road surfaces which do not align with the reference surface, road surface correction factors should ideally be developed, otherwise a number of default values are provided within CNOSSOS-EU which are taken from the Dutch national noise assessment method, Rmg2012, and therefore contain only surfaces that are common in the Netherlands. For the implementation of CNOSSOS-EU in Ireland, a project was undertaken to develop road surface corrections for at least the three most common pavement types on the TII network with no direct match to the CNOSSOS-EU database. This paper will describe the measurements taken on Irish roads, the resulting road surface corrections, and our conclusions and recommendations for using the road surface corrections.

Road Pavement Condition Index Deterioration Model for Network-Level Analysis of National Road Network Based on Pavement Condition Scanning Data

Surveying the condition of the pavement is one of the most important processes in managing the road network. The information collected during these surveys allows for the calculation of the Pavement Condition Index, which is a derivative cumulative qualitative indicator that evaluates various pavement characteristics and defects. Deterioration modelling of these measured indicators and calculated indices is a critical element and its most accurate prediction brings the process of pavement management closer to a higher quality process by more efficiently allocating funds and repair work. Many different models – both extremely complex and simple – are used in the world to simulate the condition of individual pavement indicators. However, these models are developed based on the data of a certain country or region and are not suitable in another country due to different requirements for pavement structures and other reasons. In Lithuania, measurements of the quality indicators of road surfaces with new generation survey equipment have been carried out recently but the information stored in the databases about road sections is minimal, and it becomes difficult to adapt the models applied abroad due to the missing information. The aim of this study is to create pavement condition index prediction models by evaluating such quantitative and qualitative indicators as traffic loads, road surface unevenness, type of repair, pavement age, climatic zones, and pavement construction classes.

Is the analysis of territorial compatibility in the vicinity of road hazmat transport routes a necessity for developing countries? A case study of Romania

The way dangerous goods are transported on roads within the European Union is regulated by international agreements that have been transposed into national legislation. Unlike European policies that focus on preventing major accidents involving dangerous substances in the industry, the component of territorial planning in areas exposed to technological hazards is not given similar attention when it comes to transport routes of dangerous goods. Since both the transport of hazardous materials and the activities of large industrial operators involve the handling of the same types of dangerous substances, they share similar associated hazards. Within this framework, a question arises as to whether decision-makers should accord greater consideration to the land use policies in the areas adjacent to transportation routes. In this study, the case of Romania was analyzed in detail, with the objective to firstly identify some particularities in how the primary road infrastructure is developed in relation to other European countries. Since the territorial compatibility near large industrial operators is established based on specific regulations at the national level, but there is no similar regulation for the transport of dangerous substances, another objective was to adapt and implement a methodology for the analysis of the territorial compatibility in the proximity of the national roads network. The proposed methodology utilizes open-source data and Geographic Information Systems (GIS) for analysis. It also involves the extensive application of existing rules on territorial compatibility for technological risks, specifically in the context of hazmat transport. The results of this study indicate that the primary road transport network in Romania has different characteristics compared to that of other countries, which determines a higher level of exposure to the hazards specific to the road transport of hazardous materials. Additionally, from an analysis of gasoline and diesel transport on national roads and the implementation of a territorial compatibility matrix, we observed instances of territorial incompatibility in the current state, particularly in areas close to the road, especially for scenarios with a relatively high accident frequency. Thus, the way future large road infrastructure development projects address risks related to dangerous goods transportation and the implementation of environmentally conscious land management strategies can contribute to society's sustainable development.

Wildlife mortality on roads crossing a protected area: The case of Dadia-Lefkimi-Soufli National Park in north-eastern Greece

Wildlife-vehicle collisions have been identified as an important ecological problem in most countries around the world, during the last decades. In the present work we examined the impacts on wildlife arising from two road categories crossing and adjoining the Dadia-Lefkimi-Soufli National Park (DLS NP), in north-eastern Greece. The study area is consisted of one of the most diverse fauna in Europe, with 202 bird species including 36 out of 38 European diurnal raptors, 60–65 mammal species, 29 reptiles and 13 amphibians. Vehicle collisions was the highest mortality factor in the study (83.9%) among five recorded categories, poison, electrocution, drowning, vehicle collisions and unidentified causes. 204 vehicle casualties were recorded out of 243 in total. Mammals (90.7%) were the vertebrates that mainly suffered from road mortality, including 11 species. The stone marten Martes foina contributed with the highest numbers, followed by the red fox Vulpes vulpes, the hedgehog Erinaceus roumanicus and the wild cat Felis silvestris. Although the contribution of birds on the road casualties was low, nine species were identified, including five diurnal and four nocturnal species, with raptors predominating. Most road casualties were observed in the national road network (71.6%), mainly during holidays (58.3%). Traffic volume, road category, season and blind bend were all dominant factors with different effects determining high wildlife-vehicle collision values. Mitigation measures that can reduce the harmful effects of roads on wildlife in the DLS NP are also discussed.