Open research questions in Traffic and Road Safety

What the literature leaves open

• The paper identifies challenges related to the complexity of socio-technical systems and the need for a comprehensive assessment of environmental and socio-technical factors. It notes the limitations of the study, including the static nature of the socio-technical indicators and the dependence on expert judgment.

  Spatially integrated assessment of urban road-safety conditions in complex terrain: coupling environmental resistance with socio-technical indicators · 2026 · DOI

• The paper identifies a gap in the current understanding of road traffic safety in complex terrain, highlighting the need for a comprehensive assessment of environmental and socio-technical factors. It notes that prior studies have not adequately addressed the interaction between human, vehicle, roadway, and environmental factors in complex socio-technical systems.

  Spatially integrated assessment of urban road-safety conditions in complex terrain: coupling environmental resistance with socio-technical indicators · 2026 · DOI

• Sharp descending curves pose a challenge for driver safety, as excessive speed can lead to crashes. The effectiveness of perceptual road markings on these curves is unknown, making it a challenge to design effective traffic-calming measures. The study had to account for the limitations of the driving simulator, including the lack of vestibular cues.

  Low-Cost Traffic-Calming Road Markings on Sharp Downhill Curves: A Driving-Simulator Comparison of Perceptual Treatments · 2026 · DOI

• Traffic accident data is sparse and imbalanced, and traditional models are biased toward the majority classes. Traditional models may not effectively capture spatiotemporal dependencies, as they often fail to account for the dynamic nature of traffic patterns and accident occurrences.

  Multimodal Spatiotemporal Deep Fusion for Highway Traffic Accident Prediction in Toronto: A Case Study and Roadmap · 2025 · DOI

• The dataset is limited to U.S. accident records and Google/OSM data, which may limit its applicability to regions with different road structures, driving patterns, or sensor resolutions. The model relies solely on image-text descriptions, which is insufficient for inferring dynamic processes.

  Domain-Adapted MLLMs for Interpretable Road Traffic Accident Analysis Using Remote Sensing Imagery · 2025 · DOI

• The need for location-specific analysis of road accidents. The lack of understanding of the relationship between road accidents and area characteristics in Poznań.

  A Safe Location for a Trip? How the Characteristics of an Area Affect Road Accidents—A Case Study from Poznań · 2025 · DOI

• The traditional Driver Behavior Questionnaire has limitations in addressing group-specific behaviors among commercial truck drivers. There is a need for a framework that incorporates emerging risks specific to the commercial transport environment.

  Extending the DBQ Framework: A Second-Order CFA of Risky Driving Behaviors Among Truck Drivers in Thailand · 2025 · DOI

• The literature on the effectiveness of city-wide 30 km/h speed limits in Europe is limited. Previous research lacks important aspects, such as the impact on safety, environment, and public health. The paper addresses this gap by assessing the effectiveness of 30 km/h speed limits in European cities.

  Review of City-Wide 30 km/h Speed Limit Benefits in Europe · 2024 · DOI

• There is a need for an overall study of the influencing factors of road traffic accidents as a whole.

  An Influencing Factors Analysis of Road Traffic Accidents Based on the Analytic Hierarchy Process and the Minimum Discrimination Information Principle · 2024 · DOI

• The lack of understanding of key factors affecting accident severity on mountainous two-lane roads. The need to compare the interpretability of model performances with statistical and machine learning models. The need to assess the ability of models to uncover underlying causal relationships.

  Investigating Factors Influencing Crash Severity on Mountainous Two-Lane Roads: Machine Learning Versus Statistical Models · 2024 · DOI

• In particular, little is known about how Japanese cyclists perceive risk, comply with traffic rules, and experience cycling crashes compared with riders in other regions.

  What are the behavioral features of Japanese cycling? Identifying risk-related strengths and weaknesses in a global context · 2026 · DOI

• Future research should explore real-world ACAS implementation and long-term adoption trends to support safer and more technologically integrated cycling environments.

  Safety over all? How European riders evaluate advanced cyclist assistance systems (ACAS) and their features · 2026 · DOI

• Drivers' cognitive appraisals of their performance are significantly associated with their actual driving behaviors, often in ways that remain insufficiently explored.

  Driving anxiety related cognitions as mediators: Bridging driver skills and behavioral outcomes among Turkish drivers · 2026 · DOI

• Previous studies analyzing AS primarily use traditional statistical models, which are limited by assumptions about data distribution and linear relationships.

  A comprehensive analysis of accident severity determinants in Bangladesh using machine learning · 2026 · DOI

• Many deliveries occur in the evening when visibility is reduced, yet little is known about visibility aid use by delivery bicyclists.

  The use of visibility aids by food delivery bicyclists · 2026 · DOI

• Future research should examine additional cultural and national factors and extend this approach to other road safety behaviours beyond speeding and mobile phone use.

  Cross-national variations in traffic safety culture: Insight into socio-cognitive determinants of speeding from 31 countries · 2026 · DOI

• Previous studies have obtained some pedestrian-friendly vehicle front-end shapes, which show good pedestrian protection ability, but their effectiveness in protecting pedestrian ground contact injury has not been evaluated yet.

  The effectiveness of proposed pedestrian-friendly vehicle front-end shapes and their corresponding controlled braking methods in protecting pedestrian ground contact injuries · 2026 · DOI

• Traditional crash-based evaluations fail to capture this risk proactively, especially in low- and middle-income countries, where crash data are often sparse and underreported.

  A Physics-Aided Framework for Proactive Assessment of Head-on Risk at Two-Lane Rural Horizontal Curves from Both Crash Potential and Severity Perspectives · 2026 · DOI

• Further research on the effectiveness of perceptual road markings on sharp descending curves, - Investigation of other types of road markings, - Study of the effects of road markings on different types of roads…

  Low-Cost Traffic-Calming Road Markings on Sharp Downhill Curves: A Driving-Simulator Comparison of Perceptual Treatments · 2026 · DOI

• Applying deep fusion in real-world intelligent transportation and urban planning systems, - Investigating other fusion approaches for traffic accident…

  Multimodal Spatiotemporal Deep Fusion for Highway Traffic Accident Prediction in Toronto: A Case Study and Roadmap · 2025 · DOI

• Integrate video sequences, external knowledge bases, and event causal graphs to enhance the model's understanding of accident evolution. Adapt the framework to diverse geographic contexts and multi-source imagery.

  Domain-Adapted MLLMs for Interpretable Road Traffic Accident Analysis Using Remote Sensing Imagery · 2025 · DOI

• Further research could explore the application of this framework in other countries or regions, - Additional studies could investigate the effectiveness of targeted safety…

  Extending the DBQ Framework: A Second-Order CFA of Risky Driving Behaviors Among Truck Drivers in Thailand · 2025 · DOI

• Further research is needed to assess the long-term effects of 30 km/h speed limits, - Studies should investigate the impact of 30 km/h speed limits on different populations and cities, - Research should examine the relationship between 30 km/h speed limits and other factors such as traffic patterns and air…

  Review of City-Wide 30 km/h Speed Limit Benefits in Europe · 2024 · DOI

• Further study on the factors influencing various types of road traffic accidents - Research on the transport of dangerous goods by highway - Study on the safety performance level of the railway transport…

  An Influencing Factors Analysis of Road Traffic Accidents Based on the Analytic Hierarchy Process and the Minimum Discrimination Information Principle · 2024 · DOI

• The assumption of homogeneity across different severity levels, - The constraints of the parallel lines assumption, - The need for the Brant test to assess the proportional odds…

  Investigating Factors Influencing Crash Severity on Mountainous Two-Lane Roads: Machine Learning Versus Statistical Models · 2024 · DOI

Most-cited papers in Traffic and Road Safety

• Errors and violations on the roads: a real distinction? · Ergonomics · 1990 · 1,580 citations
• Are we all less risky and more skillful than our fellow drivers? · Acta Psychologica · 1981 · 1,329 citations
• Driving speed and the risk of road crashes: A review · Accident Analysis & Prevention · 2005 · 1,024 citations
• The statistical analysis of highway crash-injury severities: A review and assessment of methodological alternatives · Accident Analysis & Prevention · 2011 · 913 citations
• The Theory of Risk Homeostasis: Implications for Safety and Health · Risk Analysis · 1982 · 875 citations
• Highway accident severities and the mixed logit model: An exploratory empirical analysis · Accident Analysis & Prevention · 2007 · 744 citations
• Do the Health Benefits of Cycling Outweigh the Risks? · Environmental Health Perspectives · 2010 · 740 citations
• Health impact assessment of active transportation: A systematic review · Preventive Medicine · 2015 · 735 citations
• Towards a general theory of driver behaviour · Accident Analysis & Prevention · 2005 · 688 citations
• Modeling traffic accident occurrence and involvement · Accident Analysis & Prevention · 2000 · 662 citations

Most recent work

• Study on a multi-factor lane-changing risk resilience assessment model based on genetic algorithm and fault tree analysis · Accident Analysis & Prevention · 2026
• A Bayesian hierarchical spatio-temporal generalized extreme value modeling for safety analysis from traffic conflicts · Reliability Engineering & System Safety · 2026
• Spatiotemporal diagnosis towards mismatch between traffic crash risks and safety governance in rapidly urbanizing cities · Accident Analysis & Prevention · 2026
• How visibility and alerts shape speed enforcement legitimacy · Transportation Research Part F Traffic Psychology and Behaviour · 2026
• Harnessing the integrated statistical machine learning for traffic crash injury-severity modeling · Reliability Engineering & System Safety · 2026
• Modelling two-vehicle crash severity under interwoven heterogeneity and interaction effects: A reliability and system safety perspective · Reliability Engineering & System Safety · 2026
• Understanding the risk factors of driving dilemmas at urban tunnel exits adjoining diverging areas: A naturalistic study · Accident Analysis & Prevention · 2026
• From Prediction to Prevention: Using Text Mining and Explainable Machine Learning for Urban Bus Accident Analytics · Risk Analysis · 2026
• The role of vehicle kinematic volatilities in expressway crash prediction and analysis: A two-part framework from road features to crashes · Reliability Engineering & System Safety · 2026
• Short-term effects of cannabis legalisation in Germany on driving under the influence of cannabis: a difference-in-differences analysis using Austria as a control · The Lancet Regional Health - Europe · 2026

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