Road Infrastructure Safety Research Articles

Influence of Transport Process Management on Exceeding Permitted Load Weights in Transport Companies

Poland is the leader in the performance of international transport in the EU, serving more than half of its market. The most common branch of transport is road transport, predominantly heavy goods transport, which contributes to the strain on road infrastructure. Furthermore, around one-fifth of those vehicles may exceed the permissible total mass. In this respect, the increasing demand for road transport further complicates the slowdown and prevention of road network degradation. Overloads have significant consequences for road infrastructure, economics, and traffic safety. Load management in transport companies is crucial for eliminating overloads. This article aims to assess how companies conducting freight transport manage the cargo weighing process in the context of potential overloads. Data from a survey among transport industry companies in Poland were analysed. Using non-parametric U Mann-Whitney and Kruskal-Wallis tests, the influence between propensity for cargo overloading and the method of cargo weighing was examined. The results indicated that the propensity for cargo overloading in TSL industry companies is significantly associated with both the occurrence of the weighing process and its method, as well as the responsibility for this process among individual participants in the transport process.

The integrated methodology for assessing the safety of the road network infrastructure in Romania.

Abstract Romania has the highest road fatality rate in the EU and the lowest perception of road quality. This study presents the implementation of a preliminary procedure and tools provided by the European Commission for the safety assessment of the DN2-E85 road infrastructure, which covers 472.23 km. This road was selected due to the high number of road deaths between 2017 and 2022. The research focuses on the application of both proactive and reactive methodologies as required by Directive (EU) 2019/1936, which requires full road network safety assessments by 2024, with subsequent assessments every five years. The proactive methodology assesses the built-in road safety of the road infrastructure based on design parameters, while the reactive methodology is based on historical data on accidents and traffic flows. The integration of these methodologies allows the classification of road segments into five risk levels. Preliminary results indicate that approximately 59% of the length of the DN2-E85 road is classified as “very high priority”, highlighting significant safety deficiencies, which require actions to immediately improve traffic safety. This study highlights the need for systematic road infrastructure safety assessments and prioritisation of high-risk segments to reduce road fatalities and improve overall road safety. The findings serve as crucial information for road safety auditors and the Romanian Road Authority - ARR, supporting the identification of high-risk areas and the allocation of resources to improve safety. In addition, this research provides a basic basis for future adaptations of road infrastructure safety assessment guidelines, considering the specific characteristics of national and county roads. By aligning with EU directives and national standards, the study aims to increase road safety and reduce the incidence of serious accidents in Romania. The insights gained from this research are essential for developing effective road safety strategies and implementing remedial measures that address the most dangerous segments of the road network.

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.

Network-level crash risk analysis using large-scale geometry features

Road traffic crashes are common occurrences that create substantial losses and hazards to society. A complex interaction of components, including drivers, vehicles, roads, and the environment, can impact the causes of these crashes. Due to its complexity, crash identification, and prediction research over large-scale areas faces several obstacles, including high costs and challenging data collecting. This study offers a method for large-scale road network crash risk identification based on open-source data, given that roadways’ horizontal and vertical geometric alignment is crucial in highway traffic crashes. This methodology includes a comprehensive technique for feature extraction from horizontal curves (H-curves) and vertical curves (V-curves) and a novel way of combining the XGBoost model’s attributes with the Harris Hawks Optimization (HHO) algorithm—referred to as the HHO-XGBoost model. Using this model on the road geometry-crash risk dataset developed specifically for this study, the HHO approach adaptively identifies the optimal set of XGBoost hyperparameters and yields favorable outcomes. This study creates a three-dimensional road geometry database that may be utilized for various road infrastructure management, operation, and safety in addition to completing a tiered risk analysis of “region-road-segment” for large-scale road networks. It also offers direction on using swarm intelligence algorithms in integrated learning models.

Assessing Multifaceted Effects of Speed Humps and Bumps: Travel Time, Safety, and Environmental Considerations

This study focuses on investigating the significant impacts of speed breakers on various parameters, including travel time delays, vehicle speeds, fuel consumption, pavement maintenance costs, and vehicular exhaust emissions. Field data was collected and analyzed to assess the effects of different types of traffic calming measures on these parameters. The findings provide valuable insights into the implications of speed breakers on road safety, environmental pollution, and overall road infrastructure management. The results reveal that the implementation of speed humps, speed bumps, and triple bumps effectively slows down vehicles, as evidenced by considerable reductions in the 85th percentile speeds. The reduction percentages were 41.65% for speed humps, 73.52% for speed bumps, and 86.27% for triple bumps. This indicates the effectiveness of these traffic calming measures in improving road safety by reducing vehicle speeds. However, the presence of speed breakers also leads to increased travel time delays. On average, traversing stretches with speed humps, speed bumps, and triple bumps resulted in delays of 9.31, 16.42, and 29.51 seconds, respectively. While the individual delay times may appear relatively short, the cumulative effect of multiple speed obstacles along a road needs to be considered. Another significant impact observed is the increased fuel consumption associated with speed breakers. The study found that for every 100 km of travel, motorcycles and passenger cars consumed approximately 12.07 km and 27.37 km of additional fuel, respectively, when the density of speed breakers was 1.33/km. This translates to a fuel consumption increase of 13.73% for motorcycles and 37.74% for passenger cars. Furthermore, the presence of speed humps was found to contribute to pavement deterioration, as indicated by decreased Pavement Condition Index (PCI) values. The study also revealed that sections with speed humps incurred significantly higher maintenance costs compared to sections without speed humps. The increase in maintenance cost ranged from 100 to 264% across different road sections, with higher traffic volumes leading to greater cost escalation. Additionally, the study confirms that lower vehicle speeds, particularly between 0-15 km/hr, are associated with higher emissions of pollutants, including carbon monoxide (CO) and other pollutants. This highlights the environmental implications of speed breakers and their contribution to urban air pollution. Doi: 10.28991/CEJ-2024-010-07-07 Full Text: PDF

Smart Accident Detection and Emergency Response System for Enhanced Road Safety

In the realm of road safety, prompt and accurate accident response is paramount to mitigating fatal injuries and saving lives. The existing approach, reliant on manual reporting to authorities or the injured party's ability to communicate with emergency services, introduces delays that can prove fatal. The presented system uses a combination of IoT modules to detect the accident and alert the EMS. It uses an accelerometer to detect the accident, a sim module equipped with a 2G sim to send an alert message consisting of the drivers details, car details, and crash location, acquired by the GPS module to the authorities and few selected individuals. The goal is to drastically reduce emergency response time, improving the likelihood of survival and quick recovery of the injured. This innovative approach not only addresses the current gaps in accident reporting but also contributes to an overall improvement in road safety infrastructure. This work uses a collection of sensors to identify an accident and point out the accident location. This data is sent as a text message to emergency services through which immediate help can be received.

Eco-efficient asphalt recycling for urban slow mobility

Cycling infrastructures contribute to advancing zero-impact transport systems, aligning with the European Commission’s proactive climate change mitigation policies. This paper explores the potential of innovative and sustainable pavements for cycling paths with mixtures composed of road-milling materials. This investigation involves low-environmental-impact bituminous-based mixtures differing from recipe, mixing method, and laying. Up to 100% secondary aggregates are used as alternative materials to design the Grande Raccordo Anulare delle Biciclette (GRAB), a 44-km cycling ring in Rome. According to the European standard EN 15804, their “from cradle to gate” life cycle analysis allows a comprehensive assessment and comparison of the environmental impact. Core and additional environmental impact categories and resource use indicators were quantified using primary data from asphalt producers and secondary data from the Ecoinvent database in the SimaPro software. Within the H2020 InfraROB project (grant agreement no. 955337), which aims at enhancing road infrastructure integrity, performance, and safety through autonomous robotic solutions and modularization, experimental sections have been constructed using a cold-mixed asphalt composed entirely of recycled asphalt and a rejuvenating additive. The results underscore the potential of the examined low-impact approach in conserving Earth’s resources, ensuring long-lasting infrastructure for vulnerable urban populations and fostering sustainable environmental management.

Analysis of Pothole Detection Accuracy of Selected Object Detection Models Under Adverse Conditions

Abstract Potholes detection is an essential aspect of road safety and road infrastructure maintenance. Potholes, which are typically caused by a combination of heavy traffic and weather, are depressions or holes in the road surface that can cause damage to specific parts of a vehicle. Autonomous vehicles, in particular, must be capable of detecting and avoiding them. Hitting a deep or sharp-edged pothole at high speed can lead to loss of control or even an accident. This makes pothole detection all the more important. The accuracy of pothole detection systems installed in autonomous vehicles may be significantly impaired by adverse weather and bad light conditions. Therefore, the classification accuracy of selected well-known computer vision models for pothole detection under these specific conditions has been investigated. The results were then compared with state-of-the-art methods. Our findings showed that we outperformed many of them when used under adverse weather and low light situations. This paper presents valuable insights into the precision of various computer vision models for potholes detection. It may aid in selecting the optimal model for a specific application.

Proactive safety assessment of urban through-roads based on GPS data

Road safety is a worldwide issue, while urban roads account for a high share of serious road injuries, especially involving vulnerable road users, such as pedestrians or cyclists. Specifically, the safety of major roads through built-up areas (through-roads) is insufficient due to mixed traffic conditions including vulnerable road users, varying driving behaviour, and many disruptions, which are combined with excessive speed.. In this context, various traffic calming measures have been implemented to improve road safety, such as gateways or pedestrian refuge islands. However, the specific safety impacts of traffic calming combined with specific characteristics of through-roads are often unknown, since most traditional evaluations have been limited by small sample sizes of crash data, as well as wide variations in physical and road characteristics. To overcome the limitations of crash-based evaluations, we used the GPS-based data from a sample of 21 Czech and 12 Polish through-roads to develop the Speed-Safety Index, which combines speed, speed variance, and traffic volume. Our study has three novelty features: (1) To assess safety, we used speed and speed variance simultaneously. (2) To complete the missing link between specific traffic calming measures and safety, we validated the statistical relationship between the developed Speed-Safety Index and crash history. (3) To prove the usefulness of the developed index, we also showed its practical interpretation by proving the effect of spacing between traffic calming measures on safety. The index proved to be well correlated to crash frequency and it also proved the effect of spacing between traffic calming measures: the longer spacing, the smaller speed-reducing effect. The paper concludes with a discussion on the limitations, which we plan to address in further research, by moving from the current macro-perspective (Speed-Safety Index on the level of through-roads) to the micro-perspective (focusing on individual directions, locations, and traffic calming measures). We also plan to investigate the method’s applicability in different contexts. If the approach proves feasible, with reliable and valid results, it may become an alternative for a proactive network-wide road assessment, as called for by the European Road Infrastructure Safety Management Directive.

Mega-Events: Assessing Road Safety through an Operating Framework. An Application for the Milano–Cortina 2026 Winter Olympic Games

To meet the United Nations and European Union goals of reducing road crash fatalities and injuries, it is also relevant to address the negative externalities due to mega-events on the road network and the local communities, to assess the safety of the road network involved, and to implement appropriate measures for different road environments. Despite their relevance, the literature often overlooks social costs and risks associated with mega-events. This study presents an operating framework for rapidly assessing the safety of the Milano–Cortina 2026—“Via Olimpica” road—which will host a significant proportion of the traffic during the Winter Olympic Games in 2026. The framework proposes a simplified Road Infrastructure Safety Management (RISM) to address the unique challenges posed by the limited time available for screening and implementation by local authorities. The framework integrates four data sources and follows a seven-step procedure. It provides recommendations for improving road safety by identifying critical road sections and blackspots. Road authorities, practitioners, and public administrations may all benefit from the framework, as it makes it easier to prioritise safety improvements within time constraints.

The impact of indirect benefits (reduced travel time, fuel use and emissions) in cost benefit analysis of road safety countermeasures.

In cost benefit analysis of road safety countermeasures, all relevant effects on safety, travel time and environment have a substantial impact during economic appraisal. However, in the most widely used road safety appraisal tools such as SafetyAnalyst and International Road Assessment Programme (iRAP), indirect effects related to travel time and environment are not considered. Most economic appraisal studies conducted for road safety countermeasures consider only the safety benefits and ignore the indirect benefits due to lack of models to evaluate them. This study attempts to document the quantitative impact of indirect benefits during economic appraisal of road safety infrastructure investments particularly from the angle of reduced crashes. To this effect, data from 9 European countries and the 20-year infrastructure improvement programme developed for the Netherlands are applied to demonstrate the impact of these indirect benefits through a quantitative study. The results show that indirect benefits increase the value of benefits by 7%, which improves the cost effectiveness of countermeasures. Consequently, the number of countermeasures selected for implementation are increased due to addition of these benefits. Travel time benefits constitute the largest share of indirect benefits with a contribution of 6% to the overall benefits due to countermeasure implementation. In conclusion, indirect benefits have a substantial impact on the computation of benefits and countermeasure selection process. In order to present improved business cases for road safety infrastructure investments, there is need to include these benefits during economic appraisal process. Travel time benefits have the highest portion of all indirect benefits compared to vehicle operating costs (VOCs) and emission benefits. The study recommends conducting more research related to travel time benefits due to countermeasure implementation.

Road infrastructure safety assessment using the integrated method - case study DN2.

This study aims to practically test, identify vulnerabilities and analyses the limits of working tools for assessing road network safety and validate the integrated method proposed by the European Commission in the context of different technical classes of national roads in Romania. The research aims to adapt, convert, and transform the calculation values of the formulas of the proactive evaluation tool to the values used by national norms for road design and construction. 2 evaluation parameters are analysed, which represent the width of the traffic lane, respectively the widths and type of shoulders. On the other hand, the study is a tool for analysing road infrastructure safety, for efficiently allocating resources and for prioritising specific road safety inspections on the most dangerous sections of roads. The case study is the comparison of the results obtained from the safety assessment of DN 2 road infrastructure, both by the proposed test method and by the method adopted by the European Commission following Member States’ comments.

The influences of human factors on road accidents in Romania in the period 2013 – 2022.

The main objective of the study is to establish a correlation between the main causes of road traffic accidents in Romania and “human factors”. The aim of the study is to show that accidents are attributed exclusively to human mistakes in a higher percentage than. The data used in the research are taken from the database of the Traffic Police-for Road traffic accidents during 2013-2022 and from the database of the Romanian Road Authority - ARR - for road safety inspections during 2018-2021. From the perspective of human factors, the research will give answers on the nature of the causes that lead to the production / favouring of road accidents in Romania and will propose solutions to address road risks to improve road infrastructure safety. As a case study, the research will focus on the human factors that contribute to road accidents on National Road 2. Compared to other national roads, on DN 2 road accidents occur with the highest number of fatalities, approximately 8.28% of all road deaths nationwide. The analysis of findings from road safety inspection reports carried out on DN2 shows that there is a correlation between road infrastructure non-conformities and causes of road traffic accidents.

Road Accident and Safety Issue in Bangladesh: A Critical Review

Road accidents are a major public health concern in Bangladesh, causing significant harm to individuals and society as a whole. Despite various initiatives taken by the government, the number of road accidents continues to increase, highlighting the need for a legal approach to address this issue. This study aims to analyze the current legal framework in Bangladesh with regards to road safety and identify potential areas for improvement. The study found that the current legal framework in Bangladesh contains several provisions aimed at promoting road safety, including the Bangladesh Road Transport Act, the Bangladesh Road Transport Corporation Act, and the Bangladesh Road Transport Authority Act. However, these laws lack effective enforcement mechanisms, and there is limited accountability for those who violate traffic rules. This has led to widespread flouting of traffic regulations and a high incidence of road accidents. The study recommends the introduction of stricter penalties for those who violate traffic rules, including fines and imprisonment. It also suggests the establishment of an independent road safety commission to monitor compliance with traffic rules and to ensure effective implementation of road safety measures. The commission should have the authority to investigate road accidents and to take appropriate actions against those found responsible persons. Additionally, the study recommends the introduction of mandatory training programs for all drivers and the provision of better infrastructure and technology to support road safety. This may include the installation of traffic lights and speed cameras, as well as the use of innovative technologies such as GPS-based monitoring systems. In conclusion, a legal approach is crucial in addressing the problem of road accidents in Bangladesh. By introducing stricter penalties, establishing an independent road safety commission, and investing in road safety infrastructure and technology, the government can help to reduce the number of road accidents and save lives. Further research is needed to understand the impact of these measures and to identify additional ways to promote road safety in Bangladesh.

Road Safety for All Road Users – Current Situation and Perspectives for 2030

Abstract This article presents a brief overview of Romania’s road infrastructure and road safety situation in general, and outlines perspectives for reducing the number of lives lost in road crashes by 2030. Romania’s road fatality rate per 100,000 population has improved overall from a 2008 high of around 15 to the current 2020 value of 8,5. However, despite a 30,8% reduction in road deaths during the past decade, Romania’s total annual number of road deaths has remained at an average of around 1890 fatalities per annum over this period, and compared to the EU average of 36,7%, Romania is positioned among the worst performing countries in the European Union (EU) in recent years in terms of road safety. A World Bank road safety management capacity review performed in 2016 found a series of factors to be contributing to this high number of road deaths, such as inadequate political commitment to effective actions to reduce road fatalities, fragmented government road safety activities across a number of regulatory entities, speed limits set at levels that exceed internationally accepted survivable limits, weak traffic law enforcement including a lack of speed enforcement cameras resulting in a failure of drivers to comply with speed limits, and a lack of structured programs to implement human error tolerant road infrastructure constructed according to Safe System principles. A series of recommendations from the capacity review were adopted since 2016, although much remains to improve road safety in Romania, especially in light of the Second Decade of Action for Road Safety 2021-2030 and the United Nations Sustainable Goals.

Road safety impact assessment practices and recommendations

Abstract This article reviews the practices for conducting Road Safety Impact Assessment (RIA). An overview of current research and methodologies related to this field is presented, and various aspects of the preparation of RSIA are analysed. The DIRECTIVE OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL on road infrastructure safety management (RISM Directive) defines the procedure “road safety impact assessment” as a strategic comparative analysis of the impact of a new road or a substantial modification to the existing network on the safety performance of the road network”; The RISM Directive provides only the basic framework for conducting such analysis by just pointing out its basic elements without providing specific methodology for it. Some countries have developed their own methodologies, others not. Although the RIA is a procedure, that was included in the initial RISM Directive (2008), Bulgaria has not yet had much experience with it, nor has a developed methodology or recommendations for it. The main aim of this article is to review and analyse international experience in conducting road safety impact assessment and to present some recommendations about it for such procedures from national teams. The article draws attention to the methods and tools used in the preparation of the RIA. This includes the collection and analysis of road infrastructure and traffic data, the study of previous safety analyses, modelling and simulations of the proposed measures, and the assessment of social and economic aspects. One of the main aspects discussed in the article is the possibility of using computer models and artificial intelligence (AI) in the preparation of the RIA. AI can be applied to process large volumes of data and perform complex risk and scenario analyses. This allows practitioners to obtain more accurate and predictable results to serve as a basis for making informed road safety decisions. In conclusion, the article emphasizes the importance of preparing Road safety impact assessment and presents different practices and methodologies that can be used in this process. The use of computer models and AI can improve the efficiency and accuracy of RSIA and contribute to achieving higher standards of road safety.

YOLO: A Competitive Analysis of Modern Object Detection Algorithms for Road Defects Detection Using Drone Images

Efficient identification of road defects is a critical concern for road safety and infrastructure upkeep. This research employs drone-captured imagery and advanced object detection algorithms to expedite defect recognition, with a specific focus on determining the optimal algorithm for prompt and precise detection. The importance of timely road defect detection, crucial for mitigating potential hazards, remains central. A comprehensive comparative analysis of contemporary object detection algorithms, encompassing YOLOv5s, YOLOv5m, YOLOv5l, YOLOv5x, and YOLOv7. The results of this study highlight YOLOv7 as the most efficient, with a notable mAP of 68.3%, closely followed by YOLOv5l (66.8%), YOLOv5m (66.3%), YOLOv5x (66%), and YOLOv5s (63%). The integration of drone-derived imagery, capturing distinct gradients, significantly enhances defect detection accuracy. Beyond road safety, this study offers valuable insights to computer vision and machine learning practitioners. By bridging technological innovation with practical implementation, it holds potential to advance road safety and transportation infrastructure quality and the use of revolutionary drone technology.

Road Accident and Safety Issue in Bangladesh: A Critical Review

Road accidents are a major public health concern in Bangladesh, causing significant harm to individuals and society as a whole. Despite various initiatives taken by the government, the number of road accidents continues to increase, highlighting the need for a legal approach to address this issue. This study aims to analyze the current legal framework in Bangladesh with regards to road safety and identify potential areas for improvement. The study found that the current legal framework in Bangladesh contains several provisions aimed at promoting road safety, including the Bangladesh Road Transport Act, the Bangladesh Road Transport Corporation Act, and the Bangladesh Road Transport Authority Act. However, these laws lack effective enforcement mechanisms, and there is limited accountability for those who violate traffic rules. This has led to widespread flouting of traffic regulations and a high incidence of road accidents. The study recommends the introduction of stricter penalties for those who violate traffic rules, including fines and imprisonment. It also suggests the establishment of an independent road safety commission to monitor compliance with traffic rules and to ensure effective implementation of road safety measures. The commission should have the authority to investigate road accidents and to take appropriate actions against those found responsible persons. Additionally, the study recommends the introduction of mandatory training programs for all drivers and the provision of better infrastructure and technology to support road safety. This may include the installation of traffic lights and speed cameras, as well as the use of innovative technologies such as GPS-based monitoring systems. In conclusion, a legal approach is crucial in addressing the problem of road accidents in Bangladesh. By introducing stricter penalties, establishing an independent road safety commission, and investing in road safety infrastructure and technology, the government can help to reduce the number of road accidents and save lives. Further research is needed to understand the impact of these measures and to identify additional ways to promote road safety in Bangladesh.

Impact of Traffic Sign Diversity on Autonomous Vehicles

Traffic sign classification is indispensable for road traffic systems, including automated ones. There is a fundamental difference in the visual appearance of traffic signs from one country to another. Each dataset has its design standards and regulations based on shape, color, and information content, making implementing classification and recognition techniques more difficult. This paper aims to assess the influence of traffic sign diversity on autonomous vehicles (AVs) by reviewing several previous studies, comparing, summarizing their results, and focusing on classifying and detecting traffic sign datasets based on color, shape, and deep learning spaces using various methods and applications. Furthermore, it covers the main challenges facing road designers and planners considering changes to road safety infrastructure. It will be argued that compiling and standardizing a comprehensive global database of traffic signs is very difficult because it is costly and complex in application. However, it is still one of the possible solutions for the coming decades. Recommendations for future developments are also presented in this study.

Road safety and road infrastructure expenditure: A bivariate analysis

A considerable body of earlier literature has analysed the determinants of road safety outcomes at the aggregate level. A sub-set of that literature has sought to assess the effect of road expenditure, both investment and maintenance spending, on road safety. The results have been inconclusive and, in part, counterintuitive. To clarify that relationship, this paper undertakes a bivariate analysis using European panel data. Three main results emerge. First, there is only limited evidence of longer-term relationships (common stochastic trends) among different measures of the variables. Second, causality tests on stationary variables suggest that the direction of causality depends on how the variables are measured. Third, unrestricted Vector Autoregression (VAR) analyses suggest that there is a positive relationship from some measures of road safety outcomes to road infrastructure investment, and that an increase in one real measure of road infrastructure investment reduces fatalities permanently, if with a lag. While not modelling the true and complex data generating processes, these bivariate analyses help address the salient empirical issues emerging from earlier literature, and the results provide a detailed description of the relationship between road safety and infrastructure expenditure.