Editorial: Calculation of Passenger Car Equivalents at Roundabouts

Editorial on the Research Topic: Calculation of Passenger Car Equivalents at Roundabouts About this Research Topic: Calculation of Passenger Car Equivalents (PCEs) for heavy vehicles represents the starting point for the operational analysis of road facilities and other traffic management applications. PCEs are used to consider the presence of heavy vehicles in the traffic stream and are expressed as multiples of the effect of an average passenger car. Moreover, the highly curvilinear nature of the roundabout design, both in urban and rural environment, has significant effects on the paths that heavy vehicles would travel; as a consequence, the interaction between the physical and performance characteristics of the heavy vehicles and the geometric features of roundabouts can produce higher impacts on traffic operations than other at-grade intersections. The PCEs at roundabouts can be affected by numerous and specific factors, which include geometric and traffic properties, and other factors (e.g. location and environment, driver behaviour), the effect of which can be significant under conditions of unlimited traffic with high saturation degrees of the traffic streams. Based on these considerations, this Research Topic aims to verify the effect of geometric and traffic-related determinants on the calculation of PCEs for heavy vehicles at modern (i.e. single-lane and multi-lane roundabouts) roundabouts and alternative types of roundabouts (i.e. turbo and flower roundabouts). Since only a few studies were based on field data or have calibrated PCEs for roundabouts, academics and practitioners during the last decade have been using microscopic traffic simulation to calculate the PCEs on roundabouts. Thus, many challenges and research themes are still open for modern and alternative roundabouts, including: how to determine the PCE of different types of vehicle that reflect the actual traffic conditions in presence of motorized and non-motorized vehicles, or how to evaluate the transferability of the Highway Capacity Manual (HCM) recommendations for heterogeneous traffic conditions to adequately explain the traffic complexities of a mixed-traffic state, or how to optimize the working parameters of microscopic traffic simulation models in view of PCEs calculations, or how to assess the likely changes to traffic flow characteristics that may result from the introduction of new technologies for vehicles and how to assess the effects on fleet composition and level of service determinations. This Research Topic welcomes contributions addressing all aspects of simulation of PCEs for modern and alternative roundabouts geared toward solving the above questions. As such, we solicit submissions of research papers dealing with themes that include, but are not limited to: • Prediction of entry lane capacity for roundabouts in heterogeneous traffic conditions and model calibration; • Estimation of capacity for roundabouts based on percentages of heavy vehicles in entering and circulating flows; • Prediction of the entry capacity based on the difference in driver’s gap acceptance behavior between cars and heavy vehicles; • Planning and designing of roundabouts under mixed-traffic flow conditions; • Case studies. https://www.frontiersin.org/research-topics/8991/calculation-of-passenger-car-equivalents-at-roundabout

Blending Efficiency and Resilience in the Performance Assessment of Urban Intersections: A Novel Heuristic Informed by Literature Review

Urban mobility underscores the vital importance of ensuring traffic efficiency on road segments, intersections, and transportation networks, especially in challenging circumstances. In this perspective, the essential approach to improving urban intersection efficiency should involve understanding critical factors for maintaining operational performance in the face of disruptions such as storms. This paper, inspired by a systematic literature review, presents a novel heuristic for evaluating urban intersection efficiency, with resilience as its guiding principle. The methodological path was designed to address the fundamental question: How can urban intersections be designed and managed to ensure efficiency and resilience in the face of disruptions? Drawing inspiration from the Highway Capacity Manual procedure, the methodological approach encompasses both pre-storm and post-storm scenarios, comparing delay times at roundabouts and signalized intersections before and after a storm. The results reveal significant changes in delay times for traffic signals, although the choice between roundabouts and signalized intersections should be context-specific, considering factors like traffic conditions, resilience requirements, and associated trade-offs. By shedding light on the interplay between intersection design, control strategies, and urban resilience, this research provides valuable insights into integrating resilience considerations into intersection performance assessment and management strategies. It also underscores how particular intersection designs can impact efficiency and recovery, essential considerations when assessing whether a road or intersection project is resilient

Proportion of Vehicles Moving Freely Depending on Traffic Volume and Proportion of Trucks And Buses

Adequate description of traffic in all intersections where traffic is not controlled by traffic lights is substantially affected by the adopted model of proportion of vehicles which move freely in traffic flow. The present study attempts to evaluate the proportion of vehicles moving freely in traffic flow depending on traffic volume and the effect of proportion of trucks and buses on this parameter. The analyses were carried out with an example of flows of vehicles moving in small roundabouts. It was observed based on the results of the analyses that the proportion of vehicles moving freely in traffic flow depending on traffic volume is best characterized by a spline, composed of three components which include quasifree traffic, uniform traffic and non-uniform traffic

An analysis of the factors influencing the selection of a given form of learning

In modern times, we observe many new trends, including technological, economic, cultural, ecological, and economic changes, which are part of the fast and uneven process of globalization. The current educational system is undergoing global changes caused by the current situation related to the COVID-19 pandemic, forcing both academic teachers and students not only to change the way they function or operate, but also to change attitudes and beliefs, especially regarding new media and remote learning. The article presents an analysis of the factors influencing the selection of a given form of learning in technical faculties from among three hypothetical options: stationary learning, remote learning, and hybrid learning. This analysis was based on the results of a survey conducted among students after two years of experience studying in the COVID-19 pandemic. The obtained results allowed for the selection of features influencing the choice of a given form of learning by the students. The knowledge of these factors is especially valuable for university authorities making decisions about the form of student learning after the end of the COVID-19 pandemic

A Heuristic Approach to Assess the Performance Efficiency of Road Intersections in Urban Environments from the Resilience Perspective

Which intersection geometry or type of control mode may affect the efficiency and resilience at urban isolated intersections before and after a disruption as a storm? Is the research question that is expected to answer in this paper. Starting from some types of urban road intersections from the realworld, this paper presents the first conceptualization of the research problem including both prestorm situations where delay times lost at roundabouts and signalized intersections are compared with each other, and post-storm situations where the delay times at roundabouts and two-way stop-controlled intersections are compared assuming that traffic signals act as stop signs after the disruption. There were significant changes in delay times for traffic signals before and after a storm. In view of future road traffic management strategies, the results may guide to select the types of intersections suitable to maintain stable operation against disruptions and to improve their resiliency

Systematic review on the evaluation of the effects of ride-hailing services on public road transportation

In the last few years, there has been a rise in interest in ride-hailing as a novel form of urban transportation and mobility service. This comprehensive literature analysis evaluates how ride-hailing services affect public road transportation in terms of traffic congestion, safety and security. The evaluation is grounded in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology, which includes a thorough search for pertinent studies, careful article screening and selection, data extraction, and quality assessment. This systematic literature review analyses and summarises data from 160 studies examining how ride-hailing services affected public road transportation. The literature review results indicated that ride-hailing services affect public road transportation positively and negatively, depending on various variables such as the regulatory environment, user behaviour, and service accessibility. The positives include greater environmental sustainability, lessening traffic congestion, and increased accessibility and comfort for riders. Nevertheless, the negatives comprise heightened competition among public transportation companies, decreased funding for public transit agencies, and perhaps even unfavourable consequences on ride-hailing drivers\u27 working conditions. Based on the results of our literature review, we can conclude that there is a need for additional research to investigate the intricate relationships between ride-hailing services and public road transportation, as well as to develop suitable policy measures to minimise unfavourable effects and maximise the potential benefits of these ride-hailing services