Road Safety Performance Research Articles

Auditing road safety achievement using MEREC–ARAS–QBKM model: an empirical study for APEC member economies

Progress monitoring and action recalibrations are advocated as promising methods for improving road safety, which significantly relates to economic stability and social development. To achieve this, an auditing framework that can evaluate road safety and aid in policymaking is urgently required. To this end, this study developed a systemic decision model that integrates the method based on the removal effects of criteria (MEREC), additive ratio assessment (ARAS), and quantile-based k-means clustering (QBKM), termed MEREC–ARAS–QBKM, with the aim of auditing road safety achievements and providing corresponding policy suggestions with substantial reliability. In particular, the performance of the traditional k-means clustering model was improved by implanting quantiles to determine the initial clustering, which overcomes the uncertainty of k-means clustering owing to the variety of initial cluster centers. Multiple comparisons of empirical results based on a case study of the Asia-Pacific Economic Cooperation (APEC) member economies verified the robustness of the proposed model, demonstrating its applicability, practicability, and reliability in handling real-world multi-criteria decision-making problems in the field of road safety. The empirical findings show that road safety developments among the APEC countries are of class differentiation, suggesting an urgent regional benchmarking. Overall, the proposed methodology empowers decision-makers and policymakers in APEC to swiftly formulate effective action plans, countermeasures, and investment schemes, ultimately contributing to the enhancement of road safety performance and socio-economic benefit across APEC members.

Revealing the mechanisms of water permeability enhancement of urban loess subgrades due to vibration application

Urban loess subgrades are affected by considerable vibrations from traffic, especially when the underground pipelines leak, and seepage under vibrations often causes road damage. However, the influence of vibrations on the water permeability of loess subgrades remains elusive. Here we address this issue by performing vibration-assisted permeability tests and scanning electron microscopy, mercury intrusion porosimetry, and suction–nuclear magnetic resonance measurements. This allowed the evolution of the saturated hydraulic conductivity (Ks), water-air migration, soil microstructure, and pore water forms to be evaluated. The water permeability of the loess subgrade is promoted by vibrations due to the increase in Ks, the acceleration of wet front migration, and the escape of entrapped air. Moreover, the value of Ks under vibration is 3–14 times greater than that without vibration, and the maximum increase occurs at a vibration frequency near the natural frequency of the loess. Furthermore, a theoretical framework of loess vibration permeability is proposed, and the mechanisms by which vibration accelerates the permeability behavior of the loess subgrade are revealed. Vibration promotes the expansion of soil pores, a decrease in the binding capacity of pore water, the mobilization of fine particles, and the formation of local low-permeability layer. Moreover, it accelerates the opening of entrapped air bubbles and the displacement of water-air, the reduction in seepage resistance. Thus, seepage water flows rapidly along infiltration channels. These findings are highly important for the road safety performance and the sustainable development of the traffic environment in loess regions.

Design and Implementation of a Car’s Black Box System using Arduino

A black box system (BBS) in a car is crucial for recording and analyzing critical data to enhance safety, investigate accidents, and improve vehicle performance. This research presents a BBS developed using Arduino for cars, aimed at using the power of modern technology for comprehensive data capture and analysis in vehicular contexts. The BBS, or Event Data Recorder (EDR), is an essential component for enhancing road safety, accident analysis, and overall vehicle performance evaluation. The proposed system uses Arduino, a versatile and cost-effective microcontroller platform, to create a robust and customizable solution. It integrates various sensors and data acquisition modules to collect critical data points, including speed, acceleration, GPS coordinates, engine performance, and vehicle diagnostics. The architecture of the system and its smooth integration into automobiles are described in this article through detailed hardware and software design. Data retrieval and analysis are made possible by the system's user-friendly interface, which helps with fleet management, driver behaviour analysis, and accident investigation. This paper addresses the importance of data privacy and security while highlighting technological improvements. It proposes measures to ensure that personal data is managed responsibly and in accordance with legal requirements. In conclusion, a major advancement in improving road safety and vehicle monitoring has been made with the integration of Arduino technology into the car's BBS. Considering data security and privacy, this system provides users with an extensive set of facts to enable them to make well-informed decisions.

Safety Assessment of Suburban-Type Arterial Roadways: New Findings Using Heterogeneity Models

This study investigates the safety performance of suburban-type roads (STRs), a category of medium-speed arterial roads characterized by high vehicular traffic and limited pedestrian and cyclist mobility. Such roadways present unique challenges in road safety, often overlooked in traditional road design focused predominantly on driver needs. By employing a correlated random parameter ordered probit model to analyze police-reported crash severity data from STRs, this research uncovers critical insights into the factors influencing crash injury severities on these roads. Our findings highlight the nuanced impact of various dimensions, such as road design, traffic volume, and environmental conditions, on STR safety; the results offer a detailed understanding of crash contexts on STRs and point toward targeted interventions for enhancing road safety. These interventions include the potential redesign of roadways to accommodate diverse user needs and the implementation of speed regulation measures tailored to specific road characteristics. This research contributes significantly to the existing body of knowledge on suburban road safety, providing evidence-based recommendations for improving the overall safety of these increasingly prevalent road types. The implications of these findings are far-reaching, offering a foundation for future studies to explore diverse methodologies in road safety analysis and to extend this research to other geographic contexts.

Assessment of road safety performance based on Entropy-RSR model

This paper develops a hybrid decision-making model, Entropy-RSR, for benchmarking road safety for Southeast Asian countries at the regional level. This model generates ranking and grouping of the countries, which provides policymakers and practitioners with a valuable tool for policymaking and decision-making in road safety management.

Possibilities to evaluate the vehicle’s accelerations through MATLAB Simulink simulations

This scientific present paper explores the methods for assessing the longitudinal and lateral accelerations of a vehicle through the combination of experimental validation and MATLAB Simulink simulations. Comprehending these accelerations is essential for a number of uses, such as stability, overall performance analysis, and vehicle safety. The first step of the study is building a detailed Simulink model of the car. With an emphasis on lateral and longitudinal accelerations, this model makes it easier to simulate a range of driving scenarios and explore how a vehicle handles and behaves under different circumstances. A key element of the study is the experimental validation of the Matlab Simulink model, which involves gathering real-world data from vehicle testing and contrasting it with simulated outcomes. Simulink model iterative refinement is made possible by the integration of simulation and experimentation, which ultimately improves the model’s predictive accuracy. The study’s conclusions demonstrate the integrated approach’s potential to advance vehicle dynamics analysis and make cars safer and more effective. Furthermore, it offers insights into the optimization of vehicle designs and the development of innovative control strategies to enhance overall road safety and vehicle performance.

Does the 80 km/h speed limit save lives in France?

Introduction: Speeding is considered to be a major contributor to road fatalities and injuries worldwide. Inappropriate speeding behavior is associated with a high casualty burden. It could be responsible for at least 30% of road accidents. Method: In 2018, the French authorities decided to introduce a new speed limit. They lowered the speed limit to 80 km/h on the unseparated interurban network. The aim was to reduce the number of fatalities and injuries and to implement some measures in line with international commitments. This paper uses different econometric models applied to time series for different groups of counties. Results: The results show a significant positive contribution of the new speed limit. The estimated number of lives saved is between 300 and 350. The overall reduction in the number of fatalities is 10%. The results also show a differentiated impact according to the local context and the different dynamics at play. Conclusions and Practical Applications: The results of this paper are in line with the scientific literature on speed limit reductions. They represent a validation of a debated public decision, while at the same time consolidating the body of knowledge on the subject, helping the decision-maker to adopt an appropriate measure to improve road safety performance.

Impact of quantitative safety targets on road fatality reduction: an empirical support toward governance plan.

The role of quantitative target setting has become an important topic in debates on the improvement of road safety performance. Specifically, there are questions regarding the relationship between quantitative safety targets and their actual effects. Although previous studies have provided important insights into this subject, their empirical findings have largely been equivocal, and research on this topic remains inadequate. Based on panel data representing 20 years of observations from 34 OECD member states, we employed nonlinear and linear panel models to investigate whether and how the attributes of quantitative road safety targets (i.e., target ambition and duration) influence their success (i.e., target completion status and rate). The results indicate that a quantitative target with a higher level of ambition is associated with a lower likelihood and rate of completion, whereas there is no support for a connection between target duration and final completion rate. This suggests that an excessively ambitious target does not necessarily result in better road safety performance and is detrimental to achieving expected fatality reductions. From an empirical perspective, this study revealed a potential interaction effect between quantitative road safety targets and practical fatality reduction performance, providing government officials and policymakers with essential references for future practices on target setting and governance planning in regard to public health.

Road Safety Efficiency on Interurban Roads in Spain.

The slowdown in economic development caused by traffic accidents in Spain, together with the disparity in the risk of death or injury due to traffic accidents in its provinces, makes it necessary to evaluate their road safety performance. Therefore, the objectives of the present research are, on the one hand, to find out the level of road safety efficiency of Spanish provinces in the period 2014-2018. On the other hand, it is also aimed to determine to what extent the annual efficiency change is originated by pure changes in efficiency or by technological changes. To achieve both objectives, the nonparametric technique of Data Envelopment Analysis and the Malmquist Index have been used based on the consideration of the Safety Performance Indicators (SPI) as the inputs of the process. The research findings show changes in the level of road safety efficiency in each of the years of the study period. Thus, it is possible to identify a geographical delimitation of the causes that generate changes in efficiency in recent years. A contraction in efficiency and technological progress is identified in part of the Spanish provinces in the north, northeast, and south of Spain.

Improvement of road safety management systems of local governments in Korea after evaluating related indicators

This study analyzes what has changed in the road safety management systems (RSMS) of local governments after evaluating the related indicators continuously from 2015 to 2019. It has evaluated 24 indicators in four areas of RSMS such as institutional management, intervention, intermediate outcome, and the final outcome, according to Han and Lee (2020). It seems that continuous evaluation of indicators of RSMSs in local governments for five years has helped to improve road safety performance in local governments. The result shows that the average overall scores have increased from 77.92 to 83.89, a 7.7% increase. This improvement should have resulted from the competition between local governments, which do not want to be at the bottom in the score comparison. The most remarkable increase has been identified in the areas of institutional management and intervention. They have increased by 13.3% and 16.0%, respectively. In terms of types of local governments, it has been found that the increase in overall scores is higher in provinces which include most rural areas than in metropolitans. However, it has been found that the improvement of institutional management and interventions are not directly associated with the increase of the intermediate and final outcomes, at least during the five years. Further studies examining the relationship between the four areas of RSMS are needed.

Development of a Road Protection Value Model as an Indicator for National Road Safety Performance Assessment from the Perspective of Drivers of Four or More Wheeled Motorized Vehicles

This paper introduces the model of Star Rating Scores (SRS) or Road Protector Scores (RPS) for Indonesian National Roads from the perspective of motorized vehicle drivers with four or more wheels, which are explored from the characteristics of traffic accidents along Indonesia's national roads. This SRS model takes into account 2 different main parameters and 4 main parameters that are the same as the main parameters of the SRS International Road Assessment Program (iRAP) and a total of 51 road attributes. The two main parameters that differ from the SRS iRAP model are the parameters for front-rear crashes and fore-side crashes when turning around. While the 4 parameters are the same as front-side collision accidents at property access, single accidents leaving the road body, front-to-front collision accidents, and accidents at intersections. In the early stages, the National Road SRS model was designed using 51 road attributes. After analysis using the Importance and Performance Analysis (IPA) method, 43 road attributes were successfully formulated for the SRS National Road model, consisting of 30 likelihood factor attributes, 10 severity factor attributes, 2 external traffic influence factor attributes, and 1 factor attribute operational speed. In addition, it is proven that the SRS National Road model is significantly different from the SRS iRAP model. The three main parameters of the National Road SRS model, namely the front-rear hit accident parameter, the front-side hit accident parameter when turning around, and the front-side hit accident parameter at property access are significantly different from the parameters of the SRS iRAP model.

Road Safety Performance Monitoring Practices: A Literature Review

Road Safety Performance Monitoring Practices: A Literature Review

Auckland Transport’s Mass Action Pedestrian Improvement Programme

Auckland's road safety performance deteriorated significantly with death and serious injury crashes increasing by more than 70% between 2014-2017 compared to the previous five years. A fifth of all pedestrian related crashes in Auckland occurred at existing zebra crossings. In response, the Mass Action Pedestrian Improvement Programme (MAPI) delivered 37 upgrades of existing at grade crossings to raised zebra crossings over 2018/19 financial year and since this time, Auckland Transport have upgraded more than 100 crossings across the network. This paper discusses the research and evaluation that were undertaken to inform the design and implementation of MAPI and to determine safety outcomes and impacts. Key learnings from the programme and the challenge of balancing safety benefits, community acceptance, and the efficient operation of the network, are discussed.

Crash Prediction Modeling for Horizontal Curves on Two-Lane, Two-Way Rural Highways Based on Consistency and Self-Explaining Characteristics Using Zero-Truncated Data

Consistency and self-explaining characteristics play important roles in road safety performance, especially at rural highway curves. This study aims to take into account the effect of several contributing factors associated with consistency and self-explaining. The scope is limited to the roads based on the crash frequency that occurred at horizontal curves of Two-Lane, Two-Way Rural Highways (TLTWRHs). The main contribution is to simultaneously consider the traffic, geometry, consistency, and self-explaining variables, as novel parameters, for a set of 224 selected horizontal curves of TLTWRHs in Iran. The curves with existing at least one fatal crash in their history for the three-year period, from 2018 to 2020, have been selected as a case study. The collected data was zero-truncated and under-dispersion. The modeling process was carried out using the Poisson, Zero-Truncated Poisson (ZTP), and Conway-Maxwell-Poisson (COM-Poisson) regression models followed by analyzing the results. The results showed that the COM-Poisson regression model could effectively be used in the case of under-dispersed zero-truncated crash data and demonstrated that there are strong relationships between the crash frequency and the consistency variables: the ratio of curve radius to the average radius of the adjacent curves (as the alignment consistency variable) and the difference between expected and existing superelevation (as the vehicle stability consistency variable). Furthermore, the findings indicated enhancing the Field of View (FOV), as one of the self-explaining characteristics of the roads, is an effective low-cost approach for improving road safety on TLTWRH horizontal curves, compared to the other measures. Moreover, the results confirmed that constructing TLTWRH self-explaining horizontal curves is four times more effective than improving its consistency in terms of crash reduction meanwhile the curve self-explaining is 33% more effective than the superelevation improvement of TLTWRH curves.

Effects of freeze-thaw cycles on high-sulfated organic soil improved by waste of glass raw materials processing factory

Changes in soil performance due to freeze–thaw cycles can lead to subsidence or swelling of asphalt, which will have a significant impact on road safety performance. The present study aims to stabilize sulfated fine-grained soil containing organic matter with waste from glass raw material production factory and to investigate the effects of Freeze–Thaw cycles on soil properties. First, to examine the effect of adding waste to the base soil before applying the F-T cycle, three compounds containing 5, 10, and 15% of waste were investigated. The results revealed that compounds containing 10, 5, and 15% of waste had the highest shear strength and CBR, respectively. Then, to investigate the effect of F-T cycles, UCS, triaxial tests, and CBR were performed for samples containing 5 and 10% waste with 90-day curing. After applying 4 different F-T cycles (3, 6, 9, and 12 cycles), while reducing the shear strength and CBR number of stabilized samples, the axial strain values showed an ascending trend. The resilience modulus was also calculated using the CBR results, indicating that in the stabilized samples, before and after the cycle, the recommended values of the standards were met. Thus, according to the results obtained for compounds containing 10% of waste, it was found that this waste can be used to reduce the amount of traditional stabilizers such as anti-sulfate cement or lime in cold regions to improve sulfated soils containing organic matter.

Road Safety Development and Economic Growth in China From 1979 to 2018

Road safety development is affected by both motorization rates and economic growth. This phenomenon is studied using the Kuznets curve model, which uses data such as the number of road fatalities, the population, the number of vehicles, and the gross domestic product (GDP) per capita, all of which are verified by applying the data envelopment analysis (DEA) model. The results showed that there were strong links between road safety development and economic growth in China. As GDP per capita rose from 1979 to 2018, the number of vehicles per person increased and the number of fatalities per vehicle decreased, producing a relationship that followed an N-shaped curve. However, in 2002, the relationship between the road mortality rate and GDP per capita followed an inverted U-shaped curve; the point at which this happened in the Kuznets curve was the turning point for road safety performance in China. Thus, road mortality rates increased as GDP per capita increased, but declined once GDP per capita exceeded 17 187 CNY. The analysis that stems from the results of the Kuznets curve model is consistent with the performance evaluation derived from the DEA-based road safety model. The findings could provide an important reference for policymakers to improve road safety under harsh economic conditions.

The impact of mobility characteristics on public transport and road safety performance in selected European cities

The aim of this paper is to investigate the impact of mobility characteristics on Public Transport (PT) and road safety performance. For this purpose, data for several large European cities on population, road network, traffic, mobility and road fatalities were collected from the European Metropolitan Transport Authorities’ reports and the European CARE database. Initially, a database was developed containing data for the period 2014–2018 and then, two linear regression models were developed. The results of the first model indicate that more bus and tram stops, increase in GDP, higher population density and PT public operation have a positive impact on PT demand, while the opposite is the case for increases in car ownership and PT fares. Based on the second model, it is revealed that increases in population density, bus and tram stops, modal share of active travelling modes, GDP and tram speed lead to road fatalities’ decrease.

Development of the road safety strategic plan in Greece, 2021-2030

Despite the most significant improvement in road safety performance among the EU countries during the period 2010-2020 and achieving the target of halving road fatalities, Greece still remains behind the EU average in terms of road fatalities per population. This paper presents the Greek Road Safety Strategic Plan for the decade 2021-2030. With this Plan, Greece adopts the Safe System Approach and the Vision Zero by 2050. The Strategic Plan is in alignment with the EU Road Safety Strategy aiming to halve road fatalities and serious injuries by 2030. Eight targets for road crash casualties’ reduction and eight targets for the improvement of road safety performance are proposed for 2030, with intermediate targets for 2025. A list of 200 Road Safety Measures within 44 Actions within the five UN Pillars is also set. Finally, an integrated system for monitoring road safety is proposed.

Redesign of existing motorway sections to increase capacity: a pilot evaluation of safety-related impacts, in Israel

In Israel as in other countries, motorway design standards are higher compared to other road types, in particular, with regard to lane and shoulder width. However, due to steadily-increasing congestion on the main road network, additional uses of the motorway space are introduced. Recently, a redesign of the road layout was applied to two sections of an Israeli motorway, which connects two major cities, Tel-Aviv and Jerusalem. The redesign aimed to provide three travel lanes instead of two, in both travel directions, within the existing roadway, by means of narrowing both shoulders' and lanes' widths; the speed limit on the redesigned sections was restricted to 90 km/h. The redesign was introduced by the Ministry of Transport as a pilot and was followed-up by evaluations. The evaluations aimed to examine capacity changes and mostly safety-related impacts of the redesign, with a particular focus on safety concerns due to the reduced standard road layout, and included after-before analyses of traffic volumes, travel speeds and road accidents. The pilot results showed that, in the first half-year of operation, daily traffic volumes increased by 20% and speeds in rush hours increased in a range of 10-30 kph, as related to the before-period, while after two-years of operation, the increase in capacity was 17%, speeds continued to be high during day-hours but, overall, speeds were lower than in the initial period of operation. In both evaluation periods, accident numbers and rates did not change significantly as opposed to previous years but safety concerns remained, due to the unchanged frequency of the events when vehicles stopped on the right shoulders. In general, the pilot did not show a deterioration in the road's safety performance following a reduced standard redesign but indicated that restricted speed limits should stay at place.

Road safety and sustainability performance: A cross-country analysis

In this paper, we study the impact of road safety on sustainability performance in the OECD area. Road safety is proxied by the severity of road accidents, whereas the sustainability performance of each country is captured by its sustainability score. Our dataset covers the period 2000-2021 and consists of 35 OECD countries. The employed panel data analysis unveils a statistically significant negative relationship between the number of severe road crashes and sustainability score. In particular, a unit decrease in the number of deaths per one million inhabitants due to road crashes leads to a half unit increase in the overall sustainability score of a country. Therefore, policy makers should undertake measures that improve the efficiency of the transport system since this translates in higher sustainability performance. Indeed, less severe road crashes do have a positive impact on the economy, the society and the environment, thus contributing to all pillars of sustainable development.