Journal of Traffic and Transportation Engineering-English Edition最新文献

{"title":"Potential application of jet 3D printing technology for crack repair on asphalt pavement","authors":"Fangyuan Gong ,&nbsp;Yuqin Yuan ,&nbsp;Xiaoyu Zhang ,&nbsp;Xuejiao Cheng ,&nbsp;Yuqi Huang ,&nbsp;Changjian Wu","doi":"10.1016/j.jtte.2025.04.002","DOIUrl":"10.1016/j.jtte.2025.04.002","url":null,"abstract":"<div><div>To clarify the key points and direction of injection 3D printing technology for repairing pavement cracks, the types and repair methods of common pavement cracks are summarized, and the characteristics of pavement crack repair methods are introduced, including advantages of the injection method. Two kinds of 3D printing technology, 3D printing main molding technology and the advantages of 3D printing technology for repairing pavement cracks are introduced. Based on injection method and 3D printing technology, the injection 3D printing technology, equipment and 3D printing materials are proposed in this paper. It is summarized as follows. (1) Jet 3D printing technology is used to repair pavement cracks without slotting cracks. Repair material in the nozzle is jetted at a high speed, and the bond strength with crack wall is high, the repair effect is good. (2) Research on the technology of automatically determining the print path after the equipment identifies cracks, so that the equipment can complete the two processes of picture confirmation print path and print head jet repair material at the same time. The efficiency and accuracy of printing cracks are improved. (3) Emulsified asphalt is modified by mineral powder, water-based epoxy resin and styrene-butadiene rubber. Asphalt is modified by rubber, SBS, polyethylene, epoxy resin, etc., or by adding two or more polymers. The materials such as polyurethane and adhesive can be modified by titanium dioxide/shape memory polyurethane composite material and Duct Tape Federation (DTF) self-adhesive suture tape. Our research group intends to use rubber and C₉ petroleum resin to modify SBS modified asphalt. It can obtain a 3D printing asphalt pavement crack repair material with good viscosity, elasticity, high temperature stability and low temperature ductility. (4) Strengthen the research on printability of asphalt, the bonding strength between repair materials and crack edges, and other performance tests. Evaluation indicators should achieve a unified standard.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 453-468"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147862973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards reduced carbon emission and sustainable performance of industrial waste-derived pervious concrete","authors":"Bright Singh Seeni ,&nbsp;Murugan Madasamy ,&nbsp;Chellapandian Maheswaran ,&nbsp;Arunachelam Nakarajan","doi":"10.1016/j.jtte.2024.12.009","DOIUrl":"10.1016/j.jtte.2024.12.009","url":null,"abstract":"<div><div>Pervious concrete provides a promising solution to reduce surface runoff in urban roads owing to its interconnected voided structure. Production of cement based pervious concrete involves higher amount of cement content affecting the sustainability in its production. Hence, Evaluation of mechanical properties and hydrological property of pervious concrete with consideration of its sustainability performance becomes vital. The study comprises of a wide range of experimental parameters of pervious concrete with different SCM’s namely fly ash, silica fume, metakaolin and ground granulated blast furnace slag (GGBS) partially in place of ordinary Portland cement. The significance of current study lies in the evaluation of the life cycle assessment and mechanical performance of pervious concrete mixes incorporating different supplementary cementitious materials (SCM) and sizes of coarse aggregates (12.5 and 20.0 mm). Replacement of 50% of the cement content by GGBS reduced the cost of production, energy consumption and carbon emission by 12.30%, 35.91% and 45.00%, respectively, contributing to effective achievement of sustainable development goal (SDG)-9 with considerable improvements in its mechanical properties.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 423-452"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spray and combustion characteristics of F-T diesel blending oxygenated fuel based on constant volume combustion chamber","authors":"Limin Geng ,&nbsp;Yang Zhao ,&nbsp;Fujia Liu ,&nbsp;Shiyu Shan ,&nbsp;Nan Gao ,&nbsp;Zhao Liu ,&nbsp;Hao Chen","doi":"10.1016/j.jtte.2024.05.008","DOIUrl":"10.1016/j.jtte.2024.05.008","url":null,"abstract":"<div><div>In this work, 20% of polymethoxy dimethyl ether (PODE) and n-butanol are blended with F-T diesel by volume, respectively, referred to as FP20 and FBU20. Based on the constant volume combustion chamber (CVCC), the spray characteristics and combustion characteristics of diesel, F-T diesel, FP20 and FBU20 under high ambient temperature and pressure are studied by using high-speed photography combined with Matlab image processing technology. Results show that the steady-state liquid spray tip penetration and spray projection area of FP20 and FBU20 are smaller than those of F-T diesel due to their good evaporation. Combustion characteristics studies show that compared to D100, the ignition delay and flame lift-off length of FT100 decrease by 22.9% and 43.6%, respectively. Compared to FT100, the flame lift-off length of FP20 and FBU20 increases by 36.8% and 44.1%, respectively. Due to the addition of high cetane number and high oxygen content PODE, the ignition delay of FP20 is shortened by 3.7%, and the ignition delay of FBU20 is prolonged by 40.1% due to the effect of high latent heat of vaporization and low cetane number of n-butanol. Compared to D100, the peak flame area of FT100 increases by 8.5%, while the peak flame luminosity decreases by 18.2%. Because PODE and n-butanol can improve evaporation and increase the oxygen content of fuel and then reduce the formation of soot, compared to FT100, the peak of flame area and flame luminosity of FP20 and FBU20 are decreased. The results of two-color method show that after adding PODE and n-butanol into F-T diesel fuel, the generation of soot and combustion temperature of the mixed fuel are reduced. Moreover, FP20 has higher oxygen content and better atomization characteristics, so the effect of reducing soot is better than that of FBU20.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 657-670"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors associated with travel speeds of young novice drivers: A systematic review","authors":"Teresa Senserrick ,&nbsp;Natalie Watson-Brown ,&nbsp;Judy Fleiter ,&nbsp;Katie Price ,&nbsp;Lisa Buckley ,&nbsp;Barry Watson ,&nbsp;Bridie Scott-Parker","doi":"10.1016/j.jtte.2024.10.006","DOIUrl":"10.1016/j.jtte.2024.10.006","url":null,"abstract":"<div><div>Young drivers are over-represented in crashes involving excess speed, with driving inexperience a known contributing factor, but not always accounted for in research investigations. This project aimed to systematically review literature on factors contributing to young novice drivers’ travel speeds. Two authors searched four databases: Embase, Scopus, transportation research information database and web of science. Preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed to select speed-related studies of drivers who were both young (aged 15–24 years) and novices (newly-licensed). Included studies examined factors directly or indirectly associated with travel speed in the “everyday” driving of passenger car-type vehicles, published in English in years 2012–2022. Of 2680 records, removing duplicates and screening resulted in 106 eligible studies, from which 26 were selected, and rated mostly of strong or moderate quality. Factors associated with driving too fast included factors relating to the individual young driver: lower global cognitive functioning, higher impulsivity and risk propensity, alcohol use, and perceptions of police speed enforcement methods as unjust. Additional social factors were having risky friends (generally), driving with passengers (adults or peers), driver-passenger mood, and some phone use. Driving environment factors were inner urban and highway settings, rural roads close-to-home and clear weather. Lower speeds were associated with hazard perception training, a parent-directed intervention when first driving independently and (weakly) viewing medical dramas. Searching roadside signs, texting, and being sleep deprived were also associated with lower speeds, but in ways that increased crash risk. The results provide insights to strengthen or develop new education programs, graduated licensing systems, and other interventions to assist young novice drivers develop and maintain safer speed management skills. Further research also is needed into the effectiveness of more general speeding countermeasures, such as speed management vehicle technologies and infrastructure treatments, specifically with young novice drivers.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 556-575"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147862976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal liquefaction of algae: A possible green alternative to petroleum-based bitumen-A review on wholly bio-based binders","authors":"Kussai Waleed Alrini ,&nbsp;Piergiorgio Tataranni ,&nbsp;Daniele Torreggiani ,&nbsp;Patrizia Tassinari ,&nbsp;Cesare Sangiorgi","doi":"10.1016/j.jtte.2025.03.007","DOIUrl":"10.1016/j.jtte.2025.03.007","url":null,"abstract":"<div><div>This literature review examines 100% bio-based binders (bio-binder) derived from algal biomass as a sustainable alternative to petroleum-based bitumen in the pavement construction industry. The traditional use of bitumen contributes significantly to greenhouse gas (GHG) emissions and environmental deterioration, highlighting the critical need for renewable, low-carbon emitting materials in response to global initiatives. Algal biomass, particularly through hydrothermal liquefaction (HTL), offers a promising alternative due to its quick growth, high lipid content, and capacity to survive in various settings, including non-arable lands and wastewater. HTL effectively transforms wet algal biomass into high-quality bio-crude oil, which may then be processed into bio-binders. Studies show that these bio-binders can match or outperform standard bitumen in terms of durability and mechanical performance. The economic feasibility of bio-binders is increasing as crude oil prices rise and biotechnology advances. Additionally, algae cultivation sequesters CO₂, which may offset emissions from bio-binder manufacturing. The transition to bio-binders has major environmental and economic benefits, such as lower carbon footprints and new market potential in renewable energy. However, issues including scalability, production costs, and energy usage arise. This paper provides a complete overview of current research, technological achievements, and future possibilities, emphasizing bio-binders' potential to alter road construction sustainably. Collaboration between governments, industry, and researchers is required to develop supportive policies and technology for widespread adoption.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 374-393"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Land transport network resilience to cascading failures: A systematic literature review of modeling, evaluation, and recovery","authors":"Wei Ren ,&nbsp;Fei Ma ,&nbsp;Zhen Shang ,&nbsp;Lei Wang ,&nbsp;Wenjun Liu ,&nbsp;Qing Liu ,&nbsp;Jinghui Li ,&nbsp;Joonho Ko","doi":"10.1016/j.jtte.2026.03.001","DOIUrl":"10.1016/j.jtte.2026.03.001","url":null,"abstract":"<div><div>Local failures in land transport networks can escalate into systemic paralysis through cascading effects, severely reducing accessibility and the efficiency of travel. The land transport network encompasses surface passenger and freight transportation systems, including road, rail, metro, public transport and land-based multimodal transport networks with clearly defined transfer connections. This study focuses on the cascading effects of interactions between services and traffic propagating within or across these modes of land transport. To summarise recent advances in modelling, evaluating and recovering from such cascading events, a systematic literature review of peer-reviewed journal articles was conducted. Using the ScienceDirect, Web of Science and Scopus databases, supplemented by cross-reference verification, 180 qualifying studies published between 2015 and 2025 were identified. Then, these research findings were systematically organised using a “modelling-evaluation-recovery” framework. At the modelling stage, load-capacity and coupled map lattice (CML) models account for nearly three-quarters of all reviewed studies, with increasing attention to multilayer interdependencies and behavioural feedback. At the evaluation stage, resilience is increasingly assessed jointly with vulnerability, robustness and reliability, using both topology- and performance-based indicators. At the recovery stage, studies propose interventions such as rerouting, mode-shift management, critical component prioritisation and resource allocation to accelerate functional restoration. Despite these advances, a gap between research and practice remains. Contributing factors include insufficient operational data and calibration, overly simplified behavioural and institutional assumptions, and the computational burden of large-scale, high-fidelity simulations. This paper examines how these limitations constrain implementation, proposing actionable solutions such as dynamic behavioural modelling, scenario libraries, data assimilation and real-world validation methods. This review maps advanced methods and metrics and provides guidance on selecting models and designing decision support tools for improving the resilience of land transport networks to cascading failures.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 491-523"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147862975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation on characterization of solid soot particle emissions using in-situ developed thermal desorption system from reactivity-controlled compression ignition engine","authors":"Sahil Rana,&nbsp;Mohit Raj Saxena,&nbsp;Rakesh Kumar Maurya","doi":"10.1016/j.jtte.2025.03.008","DOIUrl":"10.1016/j.jtte.2025.03.008","url":null,"abstract":"<div><div>This study experimentally investigates the solid soot particle number emissions from the gasoline-diesel (GD) and CNG-diesel reactivity-controlled compression ignition (RCCI) engines. The volatile organic fraction should be removed from the sampling gas before particle measurement to analyze the correct number of solid particle emissions. In the present study, a thermodesorption system is developed to remove the volatile particles from the exhaust sample. This study examines the effect of the thermodesorption system on emissions of nanoparticles from the RCCI engine. The intake manifold of the diesel engine is modified to inject gasoline/CNG to run an engine in RCCI mode. The experiments are performed at different fuel premixing ratios (<em>r</em>_p). The fuel is varied by changing the port-injected gasoline/CNG mass. A differential mobility spectrometer has been used to measure the emissions of nanoparticles. The thermophoresis and diffusion particle losses in the thermo-desorption system are estimated. It is found that the diffusion losses are 4.7%, 2.0%, 1.0%, and 0.2% for 10, 30, 50, and 100 nm diameter particles, respectively, whereas the thermophoresis losses are 7.6% for the same particle diameter. The results depict that the developed thermodesorption system can remove volatile particles with high volatile particle removal efficiency. Nucleation mode particles (NMPs) are significantly reduced with the thermodesorption system. The peak of the NMPs in the 10–30 nm size range is reduced by an order of magnitude when sampling is performed with the developed thermo-desorption system at all premixing ratios for gasoline-diesel and CNG-diesel RCCI combustion.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 639-656"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147862931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel approach for accelerated and accurate spatial conflation of connected vehicle data on GPUs and its application to real-time statewide traffic state estimation","authors":"Mark Amo-Boateng,&nbsp;Yaw Adu-Gyamfi","doi":"10.1016/j.jtte.2025.09.005","DOIUrl":"10.1016/j.jtte.2025.09.005","url":null,"abstract":"<div><div>There is a growing desire among transportation agencies to consider augmenting traditional traffic data collection with high-resolution data streaming directly from vehicles connected to the internet. Merging this dataset with traditional data streams has the potential to improve decision making for transportation systems maintenance, operations and safety. Critical use cases such as shockwave estimation, incident detection, crash risk prediction require near real-time spatial conflation to roads, and other infrastructure mounted traffic sensors. Here, we show a novel conflation algorithm, FastConflate, that combines high-resolution spatial grid cells and novel bottom-up and ring-based conflation technique for fast, accurate spatial matching of large datasets in real-time. Compared to existing algorithms, FastConflate exhibits unparalleled speed and precision, spatial indexing of 50 million points in a mere 9 ms–making it 14,000×, 17,000×, and 106,000× faster than the H3, S2, and geohash algorithms respectively. Moreover, on a standard desktop GPU, it conflates 50 million points to road networks in just 4.2 s, making it faster than cloud versions of Heavy AI-GPU database, PostgreSQL, and Google Big Query by 400×, 344×, and 41× respectively. In addition, we provide a pipeline and show that FastConflate can be applied to real-time transportation intelligence by applying statewide traffic state estimates for speed and volume. Given that FastConflate overcomes the challenges of existing algorithms by being highly accurate at intersections and interchanges, the proposed approach offers hope of implementing real-time transportation intelligence decisions which will lead to enhanced system safety and efficacy to state-wide transportation networks.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 606-623"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model and algorithm for the quantity adjustment user equilibrium traffic assignment problem with link capacity constraints","authors":"Wangxin Hu ,&nbsp;Ruqing Huang ,&nbsp;Lixuan Wu ,&nbsp;Zhongxiang Huang ,&nbsp;Guanhua Xiang","doi":"10.1016/j.jtte.2025.02.006","DOIUrl":"10.1016/j.jtte.2025.02.006","url":null,"abstract":"<div><div>This research investigates the model and solution techniques of the quantity adjustment user equilibrium link capacitated traffic assignment problem (QUE-CTAP) to provide more realistic traffic assignment results. Given that the existing quantity adjustment user equilibrium traffic assignment problem (QUE-TAP) model is limited to small experimental networks with low saturation levels, this paper defines path quantity signal intensity, eliminates the assumption of non-negative residual capacity on the path, reformulates the QUE-TAP model, and develops a QUE-TAP solution algorithm appropriate for real congested networks. The QUE-CTAP model extends the QUE-TAP by introducing explicit capacity side constraints. While it deviates from strict adherence to the QUE principle, QUE-CTAP follows a modified version by employing explicitly defined generalized quantity signal intensity instead of quantity signal intensity. Solving QUE-CTAP presents significant challenges compared to QUE-TAP. This paper introduces a QUE-CTAP solving algorithm designed for real-world networks. In the main loop, the algorithm updates the Lagrange multipliers for capacity side constraints and performs column generation simultaneously. Within the inner loop, the Lagrange multipliers serve as fixed costs for links, facilitating the sequential resolution of origin-destination (OD) pairs. Numerical results demonstrate that the models and algorithms developed in this paper effectively manage networks of practical scale. Compared to QUE-TAP, QUE-CTAP enhances capacity resource utilization by redirecting excess traffic to non-saturated paths, thereby reshaping traffic distribution patterns.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 624-638"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147863042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microsimulation and extreme value theory to assess the effect of varying levels of automated vehicles on crash risk","authors":"Hardik Gajera ,&nbsp;Ninad Gore ,&nbsp;Srinivas S. Pulugurtha","doi":"10.1016/j.jtte.2024.12.008","DOIUrl":"10.1016/j.jtte.2024.12.008","url":null,"abstract":"<div><div>Per the society of automotive engineers (SAE), automated vehicles (AVs) are likely to penetrate the system via five levels of automation. This implies that AVs and human-driven vehicles (HDVs) will coexist for a long time. The heterogeneity in traffic due to varying levels of AVs and HDVs would significantly affect safety because of uncertainty in vehicle-vehicle interactions. However, it is still unclear how the penetration of varying levels of AVs and HDVs will influence the crash risk. This study employed a microsimulation and extreme value theory (EVT) approach to assess the effect of varying levels of automated vehicles (AVs) on crash risk. A two-step process was proposed to calibrate the simulation model. In the first step, the simulation model was calibrated from an operational perspective, whereas the model was calibrated from a safety perspective in the second step. Different scenarios were formulated with different penetration rates of HDVs and varying levels of AVs. Traffic conflicts were extracted using the surrogate safety assessment model (SSAM), and the non-stationary peak-over threshold-based EVT approach was used to assess the crash risk. Relative crash risk (RCR) was used to evaluate the effect of varying levels of AVs on crash risk. The RCR compares the crash risk for different scenarios of AVs with the base scenario. For most scenarios, the RCR value was less than 1, highlighting improved safety levels under AV conditions. Further, the crash risk for both rear-end and lane-change conflicts was observed to increase with an increase in the penetration of Level 1 AVs. On the contrary, the crash risk decreased with an increase in the penetration of Level 2 and higher-level AVs. This highlights that higher safety benefits can be expected with increased penetration of Level 2 and higher-level AVs.</div></div>","PeriodicalId":47239,"journal":{"name":"Journal of Traffic and Transportation Engineering-English Edition","volume":"13 2","pages":"Pages 524-539"},"PeriodicalIF":6.8,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147862971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}