Analyzing the safety effects of different operating speeds for an autonomous shuttle bus service
DOI:
https://doi.org/10.55329/beui4479Keywords:
automated driving shuttle bus, autonomous vehicles, conflicts, market penetration rate, safetyAbstract
This study aims at evaluating the impacts of different operational speeds of an autonomous shuttle bus service on road safety by increasing Connected and Automated Vehicles (CAVs) Market Penetration Rate (MPR) and combining network characteristics. A microscopic simulation analysis was performed in order to quantify the impact of road safety of an automated shuttle bus service within traffic. In the traffic network of Villaverde, Madrid, several scenarios were simulated using the Aimsun software considering the various CAV MPRs (0%–100%), and the different operational speeds of the service, namely 15, 30, and 45 km/h. From the microscopic simulation, the vehicle trajectories were extracted and analyzed using the Surrogate Safety Assessment Model (SSAM) software that identified conflicts. Statistical analysis was then performed using negative binomial regression using the frequency of conflicts that the shuttle bus service was involved in as the dependent variable. The analysis revealed that the conflict frequency is lower when the shuttle bus operates at 45 or 30 km/h compared to 15 km/h, with the 45 km/h speed showing the largest reduction. This reduction in conflicts is probably due to the shuttle bus adapting more easily to the average traffic speed and is more synchronized with traffic flow. Furthermore, greater CAV MPR results in steadily decreased conflict frequency probably due to the automated shuttle's adaptability and collaboration with automated and connected traffic vehicles. The current study establishes a solid relationship for the conflict frequency of AV shuttles enabling stakeholders to optimize road safety towards a future of automated traffic.
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Author Biographies
Maria G. Oikonomou, National Technical University of Athens, Greece
Maria G. Oikonomou is a Civil Transportation Engineer, PhD Candidate and Research Associate at the Department of Transportation Planning and Engineering at the School of Civil Engineering of the National Technical University of Athens (NTUA). She holds a Civil Engineering Diploma from NTUA majoring in Transportation Engineering since 2019.
CRediT contribution: Conceptualization, Data curation, Formal analysis, Methodology, Writing—original draft.
Marios Sekadakis, National Technical University of Athens, Greece
Marios Sekadakis is a Civil – Transportation Engineer, Research Associate and PhD Candidate at the Department of Transportation Planning and Engineering at the School of Civil Engineering of the National Technical University of Athens (NTUA). In 2020, he graduated in Civil Engineering from the National Technical University of Athens (NTUA) majoring in Transportation Engineering. He has more than four years of experience in several aspects of traffic engineering and road safety.
CRediT contribution: Conceptualization, Formal analysis, Methodology, Writing—original draft.
Christos Katrakazas, National Technical University of Athens, Greece
Dr. Christos Katrakazas is a Civil Engineer, PhD, and a Research Associate at the Department of Transportation Planning and Engineering at the School of Civil Engineering of the National Technical University of Athens (NTUA). He holds a Civil Engineering Diploma from NTUA majoring in Transportation Engineering (2013) and a Ph.D. in safety of autonomous vehicles from Loughborough University (2017). After finishing his doctoral studies, he worked for 8 months as a Research Associate at Loughborough University, and for two years at the Chair of Transportation Systems Engineering at the Technical University of Munich (TUM), Germany.
CRediT contribution: Conceptualization, Methodology, Writing—review & editing.
George Yannis, National Technical University of Athens, Greece
Dr. George Yannis is Professor and Director of the Department of Transportation Planning Engineering at the National Technical University of Athens (NTUA). He leads the NTUA Road Safety Observatory, a Center of Research and Innovation Excellence with global recognition for its highly valuable contribution to safer mobility for all, in Greece, in Europe and worldwide. He has a thorough and broad understanding of the transportation sector, through his active involvement for more than 30 years as engineer, academic, advisor and decision maker in all areas of transportation planning and engineering at national and international level, with emphasis on data science.
CRediT contribution: Supervision.
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Copyright (c) 2025 Maria G. Oikonomou, Marios Sekadakis, Christos Katrakazas, George Yannis
This work is licensed under a Creative Commons Attribution 4.0 International License.
Funding data
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Horizon 2020 Framework Programme
Grant numbers No 875530
