IATSS Research最新文献

{"title":"Changes in road traffic fatalities in France over a decade: Disentangling exposure and fatality risk","authors":"Mohamed Mouloud Haddak,&nbsp;Nathalie Havet,&nbsp;Bouthayna Hayou,&nbsp;Abdoudramane Ganame,&nbsp;Alexis Penot","doi":"10.1016/j.iatssr.2026.09.007","DOIUrl":"10.1016/j.iatssr.2026.09.007","url":null,"abstract":"<div><h3>Introduction</h3><div>In a context of demographic ageing and changing mobility practices, understanding how fatality risks evolve once exposure to traffic is considered is essential for designing effective prevention policies.</div></div><div><h3>Method</h3><div>This study analyses changes in road fatality risks in France between 2007-2008 and 2018–2019 using police-reported fatal crash data combined with individual travel data from the national mobility surveys. Exposure-based fatality rates are estimated per million person-hours travelled. Analyses are conducted by gender, age group, and type of road user. A decomposition approach is used to disentangle changes in the number of fatalities attributable to variations in exposure from those attributable to changes in fatality rates.</div></div><div><h3>Results</h3><div>Over the study period, annual road fatalities decreased by 15%, while total travel time increased by 22%, resulting in a 30% reduction in the overall exposure-based fatality risk. However, trends differed markedly across casualty categories. Young adults (17–29) and the elderly (70+) showed the highest fatality risks per hour travelled. Motorised two-wheeler riders remained the most at-risk despite declining fatality rates. Cyclists experienced a doubling of fatality risk, driven primarily by an increase in fatality rates rather than by greater exposure. Decomposition results show that improvements in fatality rates offset rising exposure for most groups, except for cyclists.</div></div><div><h3>Conclusions</h3><div>These findings underscore the need for targeted road safety policies that address both exposure and risk. Improving infrastructure and protective measures for cyclists, alongside adaptations for an ageing population and high-risk motorised users, appears critical to sustain the decline in road deaths.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 3","pages":"Pages 1182-1192"},"PeriodicalIF":3.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149140872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of yellow interval adjustment on red-light running behavior: A before-and-after study using LiDAR","authors":"Mojtaba Naseri,&nbsp;Neda Dehestanimonfared,&nbsp;Anam Ardeshiri,&nbsp;Nasim Samadi,&nbsp;Ehsan Mehryaar,&nbsp;Mansoureh Jeihani","doi":"10.1016/j.iatssr.2026.08.006","DOIUrl":"10.1016/j.iatssr.2026.08.006","url":null,"abstract":"<div><div>Red-Light Running (RLR) is a major traffic safety issue, often influenced by signal timing design, particularly the clearance interval and its specific yellow interval duration. This study investigates the impact of yellow interval adjustments on RLR behavior at a signalized urban intersection in Baltimore, Maryland. A before-and-after experimental design was employed, using high-resolution LiDAR sensors to capture vehicle trajectories, RLR events and red-light violator speeds with high accuracy. Yellow intervals were increased on north-south approaches and decreased on east-west approaches. The study analyzed RLR event frequency and violator speeds, normalized by traffic volumes, and applied Chi-square and <em>t</em>-tests for statistical evaluation. Results indicate a statistically significant reduction in RLR events following an increase in yellow duration, while a decrease in yellow time did not significantly change violation frequency. However, a notable increase in violator speeds was observed on approaches with reduced yellow time, suggesting increased safety risks. Conversely, increased yellow interval was associated with lower violator speeds. These findings emphasize that even when RLR frequency remains unchanged, speed-related severity metrics are sensitive to yellow interval changes. The study highlights the value of high-resolution sensing technologies in traffic safety research and provides practical insights for signal timing optimization to enhance intersection safety.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 3","pages":"Pages 1146-1153"},"PeriodicalIF":3.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149140982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Random forests for road traffic safety research: Recent advances, empirical applications, and future directions","authors":"Yingheng Zhang,&nbsp;Dongyu Wu","doi":"10.1016/j.iatssr.2026.08.005","DOIUrl":"10.1016/j.iatssr.2026.08.005","url":null,"abstract":"<div><div>This paper presents a consolidated overview of random forest-based methods for road traffic safety research, mainly focusing on recent methodological developments tailored to particular needs in three typical crash data modelling tasks: crash frequency modelling, crash injury severity modelling, and countermeasure evaluation. Along the way, basic ideas behind the traditional random forests and how they fit with crash data analytics are first described. Newer forest-based alternatives are then detailed, together with selected empirical applications for illustration. Random forests have achieved significant success in this field due to their intuitive algorithmic ideas and competitive predictive performance, and we believe that a comprehensive summary of their new features would be helpful for road traffic safety researchers and practitioners to better exploit this strand of tools. Lastly, future research directions are outlined.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 3","pages":"Pages 1078-1087"},"PeriodicalIF":3.4,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149153592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prevalence and predictors of speeding in two Ghanaian cities: Implications for road safety improvement","authors":"Simon Ntramah,&nbsp;Francis Afukaar,&nbsp;Williams Ackaah,&nbsp;Lamisa Ashraf,&nbsp;Yuan Shang,&nbsp;Nukhba Zia,&nbsp;Abdulgafoor M. Bachani","doi":"10.1016/j.iatssr.2026.05.007","DOIUrl":"10.1016/j.iatssr.2026.05.007","url":null,"abstract":"<div><div>Globally, about 1.19 million people died from road traffic injuries in 2021, of which more than 90% occurred in low- and middle-income countries. Every 1% increase in speed results in a 4% likelihood of a fatal crash and a 3% risk of a serious crash. The study aimed to establish the prevalence and predictors of speeding in two Ghanaian cities–Accra and Kumasi–across six rounds of data collection between 2022 and 2024. Microwave radar guns were used to unobtrusively observe vehicle speeds from 15 sites per city. Every site was observed for five daily sessions, for two weekdays and one weekend per data collection round. The prevalence of speeding was comparatively higher in Accra than in Kumasi (54% vs. 31%). Speeding generally decreased over the observation rounds for both cities with significant differences across the rounds (<em>p</em> &lt; 0.001). When adjusted for vehicle, driver and environmental factors, speeding in both cities was more likely among young drivers, male drivers, SUVs, motorcycles, and sedans (<em>p</em> &lt; 0.05). Other speeding predictors included company-owned vehicles and weekends (p &lt; 0.05). Empirical evidence from the study is useful for designing strategies to improve road safety in urban Ghana.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 963-970"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the effectiveness of emergency pull-offs in reducing the impact of stopped vehicles on mainline traffic","authors":"Mohammad Khojastehpour,&nbsp;Yangsong Gu,&nbsp;Jacob Tyer,&nbsp;Lee D. Han","doi":"10.1016/j.iatssr.2026.05.006","DOIUrl":"10.1016/j.iatssr.2026.05.006","url":null,"abstract":"<div><div>Freeway emergency pull-offs provide designated areas for vehicles with emergencies or breakdowns. Pull-offs provide broad lateral clearance between stopped vehicles and the mainline through traffic. Despite their wide applications on state freeways, no studies have specifically evaluated the benefits of these pull-offs so far. This study aims to untangle whether pull-off areas would mitigate the impact of stopped vehicles on general lanes' traffic flow. To this end, the study integrates three datasets: video footage, incident data, and traffic flow data. The pruned exact linear time (PELT) algorithm was applied to detect sharp change points in the passing traffic's speed and volume over a time series. These abrupt changes capture sudden disruptions in traffic flow triggered by stopped vehicles, which, in turn, can be used to measure the impact of stopped vehicles. The speed and volume of mainline traffic were compared between scenarios involving vehicles on the shoulder and scenarios involving vehicles on pull-offs, while other traffic conditions are similar. The results indicate that there is a larger reduction in mainline traffic speed when vehicles stopped on the shoulder (speed reduction of 40%) than when vehicles parked on pull-offs (speed reduction of 17%). Likewise, on average, volume was reduced by 3% when vehicles were on the shoulder and by 0.1% when vehicles were in pull-offs. This study consolidates the operational benefits of installing emergency pull-offs.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 989-1000"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Safety over all? How European riders evaluate advanced cyclist assistance systems (ACAS) and their features","authors":"Sergio A. Useche,&nbsp;Steve O'Hern,&nbsp;Francisco Alonso,&nbsp;Dorothea Schaffner,&nbsp;Javier Gene-Morales,&nbsp;Milad Mehdizadeh,&nbsp;Mette Møller,&nbsp;Trond Nordfjærn,&nbsp;Felix W. Siebert,&nbsp;Nora Studer,&nbsp;Oscar Oviedo-Trespalacios","doi":"10.1016/j.iatssr.2026.05.002","DOIUrl":"10.1016/j.iatssr.2026.05.002","url":null,"abstract":"<div><div>As cycling gains traction as a sustainable transport mode, enhancing cyclists' safety has become a key priority within European policy. Among the various developments introduced, Advanced Cyclist Assistance Systems (ACAS) stand out as a promising technological innovation. However, research on their perceived value and adoption remains limited, particularly regarding user preferences and demographic differences.</div></div><div><h3>Aim</h3><div>This study aimed to examine European cyclists' evaluation of five ACAS types and their core functional features, as well as to explore demographic differences, particularly in relation to cyclists' gender and age.</div></div><div><h3>Method</h3><div>This study used the data provided by 6167 cyclists (47.4% females; 51.5% males; 1.1% others) from 19 European countries. Participants provided self-reported evaluations of five ACAS types (environmental monitoring, rider visibility enhancement, real-time information, crash prevention-assistance, and post-crash appliances) along with key features (safety contribution, reliability, ease of use, novelty, and everyday need).</div></div><div><h3>Results</h3><div>Among ACAS types, visibility-enhancing systems (designed to increase cyclists' conspicuity) and environmental monitoring technologies received the highest valuations, while real-time information systems were rated the lowest. Safety contribution was the most highly valued attribute across all ACAS features. Additionally, gender differences were observed, with female cyclists prioritizing visibility and safety-related aspects. In contrast, male cyclists –while also favoring visibility-improving ACAS– placed greater emphasis on ease of use as a core feature.</div></div><div><h3>Conclusion</h3><div>These findings highlight the importance of user-centered ACAS design and suggest that broader adoption may depend on improving system reliability, regulatory frameworks, and alignment with cyclists' needs and attitudinal factors. Future research should explore real-world ACAS implementation and long-term adoption trends to support safer and more technologically integrated cycling environments.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 951-962"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reevaluating pedestrian signal timing for an aging population: A case study of elderly walking speeds in Bangkok","authors":"Tatree Rakmark,&nbsp;Kasem Choocharukul","doi":"10.1016/j.iatssr.2026.04.001","DOIUrl":"10.1016/j.iatssr.2026.04.001","url":null,"abstract":"<div><div>As of December 2023, approximately 20.08% of Thailand's population was classified as elderly, officially designating the country as an aged society. This demographic shift highlights the need for infrastructure adaptations, particularly to enhance pedestrian safety and ensure safe crossings. This study investigates the walking behavior of elderly pedestrians at six signalized crossings with countdown displays in Bangkok, Thailand, where current crossing times may not adequately accommodate slower walking speeds. The study identifies factors influencing elderly walking speeds and compares them with the design standards specified in the Highway Capacity Manual (HCM) (2022). Statistical analyses, including <em>t</em>-tests, ANOVA, and Kruskal-Wallis tests, were conducted to evaluate variations in walking speeds under different conditions. Data from 227 elderly pedestrians indicate that their 15th percentile walking speed does not significantly differ from the HCM (2022) standard. Nevertheless, at three of the six crossings, the design walking speed exceeds the 15th percentile, potentially posing difficulties for elderly pedestrians. Further analysis shows that crossing location and carrying conditions have a significant impact on walking speed. A linear regression model was also developed to estimate appropriate walking speeds, aiming to align crossing times with the proportion of elderly pedestrians. The findings support data-driven recommendations for designing safer and more accessible pedestrian crossings that better serve the aging population.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 1001-1010"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Explainable and hybrid machine learning for predicting fatal crash risk","authors":"Hussein Khanjar,&nbsp;Abdolmajid Erfani","doi":"10.1016/j.iatssr.2026.06.004","DOIUrl":"10.1016/j.iatssr.2026.06.004","url":null,"abstract":"<div><div>Road traffic fatalities remain one of the most persistent public safety challenges, demanding predictive models that are not only accurate but also reliable and interpretable. While numerous machine-learning models have been developed for crash severity prediction, most remain limited in three critical dimensions: they simplify the unit of analysis by focusing only on the driver or the most severe occupant per crash, they emphasize predictive performance while neglecting model confidence and probability calibration, and they often function as black boxes lacking interpretability for real-world decision support. To address these gaps, this study proposes a calibrated hybrid machine-learning framework for nationwide, person-level prediction of fatal versus non-fatal outcomes among individuals involved in fatal crash events using over 745,000 records. The framework integrates gradient boosting, ensemble stacking, and post-hoc probability calibration to produce both high discrimination and trustworthy risk estimates. Results demonstrate that the Hybrid Calibrated Ensemble achieves strong and reliable performance, outperforming single classifiers in probability alignment while maintaining comparable discrimination. Subgroup analyses across gender, person type, seat position, and rural–urban context confirm the model's stability and fairness. SHAP-based explainable AI further reveals that ejection status, restraint use, harmful event type, age, and airbag deployment are dominant determinants of fatality risk, with clear nonlinear effects aligned with crash-mechanics.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 1011-1021"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How to improve public support for a 30 km/h speed limit in built-up areas?","authors":"Teun Uijtdewilligen,&nbsp;Fabiënne Schmidt,&nbsp;Wendy Weijermars,&nbsp;Agnieszka Stelling","doi":"10.1016/j.iatssr.2026.05.008","DOIUrl":"10.1016/j.iatssr.2026.05.008","url":null,"abstract":"<div><div>Reducing speed limits in built-up areas to 30 km/h could considerably improve road safety, yet the effectiveness depends on the reductions in actual driving speeds which, in turn, are related to the general public support for the measure. Therefore, this study investigates the public support in Europe for reducing the speed limit to 30 km/h in built-up areas using the ESRA3 data.</div><div>The support for limiting the speed limit to 30 km/h in built-up areas was found to be quite low; more than two out of five European respondents opposed the measures, about one fifth was neutral and less than two fifth supported the measure. An ordinal logistic regression model showed that car drivers, 18–34 year olds, males, people with a lower than comfortable income, and residents of rural areas were more likely to oppose the measure. Moreover, opponents were less likely to agree with statements highlighting the positive effects of the measure and more likely to agree with statements highlighting the negative effects. The main negative beliefs associated with the measure seem to be potential negative side effects, as well as that the measure would be a burden for people, would be difficult to enforce and that it would limit people's mobility.</div><div>Policy makers can use the results from this study when developing a strategy to increase support for lowering the speed limit in built-up areas, which is important as the level of support is associated with compliance to the speed limit.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 971-979"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of selected factors on the pedestrian injury severity using MAIS classification","authors":"Kateřina Bucsuházy,&nbsp;Pavlína Moravcová,&nbsp;Martina Sedláčková,&nbsp;Robert Zůvala","doi":"10.1016/j.iatssr.2026.05.005","DOIUrl":"10.1016/j.iatssr.2026.05.005","url":null,"abstract":"<div><div>Pedestrians represent the most vulnerable road users, and a comprehensive understanding of injury mechanisms and the factors contributing to injury severity is crucial for the development of effective safety measures. The presented study investigates the factors influencing pedestrian injury severity during frontal vehicle collisions, utilizing the Czech In-Depth Accident Study (CzIDAS) data, which enables a detailed system-level analysis encompassing the vehicle - road infrastructure – human. The severity of pedestrian injuries was assessed using the Maximum Abbreviated Injury Scale (MAIS) as an objective medical classification that addresses the limitations and potential biases associated with subjective injury scoring. The dataset was not restricted by pedestrian age or vehicle type, thereby allowing for a broad and representative analysis. As key factors significantly influencing pedestrian injury severity were identified: the impact speed, pedestrian age, and vehicle-specific characteristics such as Front/Top Transition Point Height, vehicle mass, or vehicle front type. The results of this study offer essential insights into enhancing road safety, highlighting the importance of implementing targeted interventions aimed at reducing pedestrian injuries.</div></div>","PeriodicalId":47059,"journal":{"name":"IATSS Research","volume":"50 2","pages":"Pages 980-988"},"PeriodicalIF":3.4,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148539415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}