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Transfer between the metro (underground railway system) and buses is standard in many cities, and the simultaneous arrival of these two modes can provide passengers with a smoother transfer experience. However, previous synchronous transfer studies rarely consider different public transport modes simultaneously. This paper presents an optimization model that maximizes the number of metro and bus network synchronizations considering the connection level. An improved algorithm that combines simulated annealing (SA) and artificial bee colony (ABC) is proposed. The best nectar source position in history is combined with the SA operation. The ABC and simulated annealing and improved artificial bee colony (SA-IABC) algorithms are used to solve the model using the Nanmendou metro station and the bus stations within 1.2 km around it in Fuzhou City, China. The results show that ABC and improved SA-IABC algorithms increase the synchronization times of the metro and bus network by 17% and 24% on average, respectively, without expanding the departure frequency. Key words: connection and transfer, connection level, simultaneous transfer, optimization model, artificial bee colony algorithm, 1. Introduction Urban public transport carries the daily travel of urban residents. The smooth connection between public transport modes depends on efficient and convenient transfer. Synchronization times are an essential [...]

Expressway crashes in interchange areas are a critical concern in China, posing significant economic and social challenges. Utilizing three years of crash data from the Beijing-Shanghai Expressway, this study investigates the transferability and heterogeneity of crash characteristics between interchange and noninterchange areas, as well as the temporal shifts in factors influencing injury severity levels. The research employs four series of random parameters logit models to estimate three potential crash injury severity outcomes of severe injury, minor injury, and no injury (based on the most severely injured individual in each crash) and to identify key determinants, encompassing driver, vehicle, roadway, environmental, temporal, traffic, and crash attributes. Likelihood ratio tests and out-of-sample predictions are utilized to assess the temporal stability and transferability of crash area characteristics. Additionally, the marginal effects of various determinants are calculated to understand their influence across different year periods and crash types. Key variables such as overspeed, single-vehicle, AADT (annual average daily traffic volume), Ls[sub.min], and other crash type indicators are identified as significant random parameters, demonstrating heterogeneity in means and variances. Notable distinctions are observed between interchange and noninterchange crashes, indicating nontransferability, with most significant indicators revealing temporal instabilities. Furthermore, factors such as multivehicle involvement, buses, and nighttime conditions are identified as risk indicators, notably increasing the likelihood of severe injuries. These insights are invaluable for expressway designers and decision-makers, aiding in understanding the contributing mechanisms of various elements. This study suggests that stricter enforcement measures are crucial to prevent random lane changes, particularly at interchange entrances and exits. Additionally, effective management strategies and enforcement countermeasures should be implemented to mitigate crash injury outcomes in both interchange and noninterchange areas., Author(s): Fang Wang [1]; Chenzhu Wang (corresponding author) [2]; Said M. Easa [3]; Siqi Lian [4]; Fei Chen [2]; Jianchuan Cheng [2] 1. Introduction In China, 211,074 motor vehicle crashes [...]

This study proposes random-parameters multinomial logit models, with heterogeneity in means and variances, to explore the differences in the factors influencing injury severities of drivers involved in different types of two-vehicle crashes. The models are verified using crash data from the United Kingdom (UK) over three years (2016-2018). Three types of crashes are separately identified (car-car, car-truck, and truck-truck crashes). In this study, a wide variety of potential variables, including the driver, vehicle, road, and environmental characteristics, are considered, with two possible injury-severity outcomes: severe and slight injury. The results show that unobserved heterogeneity existed for young drivers in both car-car and truck-truck crash models and the 30mph speed limit in the three separate models. Remarkably variations are observed in crashes involving different types of vehicles. The driver's age and gender, speeding, sideswipes, presence of junctions, weekdays, unlit, and weather conditions significantly impact driver-injury severities in various types of vehicle crashes. These findings are expected to help policymakers seek to improve highway safety and implement proper safety countermeasures., Author(s): Qiang Wu [1]; Dongdong Song (corresponding author) [2]; Chenzhu Wang (corresponding author) [3]; Fei Chen [3]; Jianchuan Cheng [3]; Said M. Easa [4]; Yitao Yang [5]; Wenchen Yang [6,7] [...]

High fatality rates in frequent rear-end crashes have underscored significant safety concerns in China. This study aims to explore the mechanisms and determinants of rear-end crashes, with a particular focus on the factors influencing crash severity during weekdays and weekends (W-W). Employing the Random Parameter Logit Model (RPLM) to account for variability in data, we analyzed W-W rear-end crashes on the Beijing-Shanghai Expressway in Jiangsu province from 2017 to 2019, considering three severity levels: no injury, minor injury, and severe injury. Our comprehensive analysis covered variables from temporal, roadway, vehicle, crash, and environmental categories, alongside calculating the marginal effects of each significant variable on crash severity. Findings reveal temporal instability over the three-year period and notable differences in W-W crash severity. Out of all variables, four displayed random parameter characteristics, indicating potential interactions that influence crash outcomes. Specifically, our results indicate that rear-end crashes involving three or more vehicles on bridges are more likely to result in casualties. Interchange segments typically saw no injuries in two-vehicle crashes. Speeding during winter or on sunny days significantly increases the risk of injuries and fatalities. Furthermore, rear-end crashes in interchange areas during winter are particularly prone to causing injuries. These findings offer guidance for the development of effective safety countermeasures targed at different pediods. [ABSTRACT FROM AUTHOR]

Due to the effects of low-pressure and hypoxic environments at high altitudes, drivers in high-altitude areas exhibit increased perceived reaction times, leading to challenges in accurate speed estimation and handling judgment. This study aims to quantitatively analyze the impact of plateau environments on operating speeds at interchange exit ramps. Utilizing a UC/win-road simulator, six scenarios of expressway exit ramps were constructed. The simulation experiments involved 50 participants (35 males, 15 females) from Nanjing, China (altitude of 50 m) and 50 participants (36 males, 14 females) from Lhasa, China (altitude of 3,650 m). This research focused on examining the influence of the plateau environment on drivers' operating speeds, investigating variations in speed between drivers in plain and plateau areas, across genders, and during different acclimation periods. It also aimed to predict operating speeds at the midpoint and exit of the curve on the exit ramp for drivers in both plain and plateau areas. Based on these predictions, the study elucidated the trend of operating speed as influenced by the low-pressure and hypoxic conditions of the plateau, as well as the characteristics of the exit ramp's horizontal curve. Additionally, the research uncovered the internal correlations and potential reasons linking operating speed to drivers' perception and response abilities, physiological and visual load levels, and driving styles. [ABSTRACT FROM AUTHOR]

This study focuses on solving the problem of metro first/last mile, studying the method for designing microcirculation bus routes and coordinating schedules considering the impact of shared bicycles. First, we propose a bilevel mixed-integer programming model for designing microcirculation bus routes and coordinating schedules considering the impact of shared bicycles. The upper-level model minimizes the weighted sum of the travel time cost of passengers and the operating cost of public transport enterprises, and the lower-level model maximizes the number of passengers served by microcirculation bus routes. Then, an improved genetic algorithm is developed to solve the model, called the Monte Carlo adaptive genetic algorithm (M-GAI). Finally, the proposed model and algorithm are evaluated using the case study in the area near the Fubao metro station of Shenzhen Metro Line 3. Results show that if the impact of shared bicycles is not considered, the passenger demand will be greater than the actual value, and the operating cost of public transport enterprises will be increased by 36%. Compared with GAI, the average number of iterations of M-GAI is reduced by 31%, and the objective function value is decreased by 4%. In addition, when the number of routes increases, the average waiting time of passengers is shortened, the average attendance rate of microcirculation buses increases, and the average empty distance of each vehicle is shortened. However, the operating cost of public transport enterprises will increase with the number of routes. Finally, when weight factors α and β are 0.6 and 0.4, respectively, and the sum of the travel time cost of passengers and the operating cost of public transport enterprises reach optimal. [ABSTRACT FROM AUTHOR]

More collisions occur at the exit ramps of expressways due to frequent lane-changing behavior and interweaving between vehicles. Young drivers with shorter driving mileage and driving experience, radical driving styles, and worse behavior prediction are likelier to be involved in collisions at the exit ramps. This paper focuses on the correlation analysis between young drivers' characteristics and their visual and physiological attributes at expressway exit ramps. First, the driver's gender, driving experience, and mileage are classified. Then, seven expressway exit models are established using the UC/Win road modeling software. The driver's driving plane vision is divided into four areas using the K-means clustering algorithm. In addition, the driver's visual and heart rate attributes were analyzed at 500 m, 300 m, 200 m, and 100 m away from an expressway exit. The results show that the visual attributes, gender, and driving mileage of young drivers strongly correlate with the fixation times and average saccade amplitude. In contrast, the driving experience has almost no correlation with the fixation behavior of young drivers. Young drivers' driving experience and mileage strongly correlate with cardiac physiological attributes, but there is virtually no correlation with gender. The practical implications of these results should be helpful to highway planners and designers. [ABSTRACT FROM AUTHOR]

To improve the traffic efficiency of bus at a group of intersections and reduce their delay, this paper develops a speed guidance strategy for buses under travel time control at intersection groups. The approach considers the influence of bus departure time, bus station arrival rate, and bus station dwell time. Simulation experiments are carried out on three consecutive intersections along Jinshan Avenue in Fuzhou, China. Results show that the average travel time of buses, the average delay of buses, and the average delay per capita in the priority direction are reduced by 5.5%, 9.9%, and 9.4%, respectively. The optimal rate of the average number of bus stops reached 15.2%. The indicators of the non-priority direction of social vehicles are not significantly affected. It shows that the efficiency of buses has improved after implementing the speed guidance strategy at the intersection groups without affecting the social vehicles as far as possible. [ABSTRACT FROM AUTHOR]

Evaluating the reliability of a bus line can provide useful information on the service performance of the city's bus transit system and the need for improvements. This paper presents a reliability evaluation model of a bus line based on information entropy. The model integrates the weighted bus-stop index and the variation index of bus travel time. To better determine the weights of the bus stop, six indices were established based on three characteristics: passenger flow, bus-stop properties, and the environment. The proposed model was applied to typical bus lines in Fuzhou, People's Republic of China. The results show that most bus-stop reliabilities at the peak period were smaller than those at the off-peak period. In addition, for either peak or off-peak period, the reliability shows a slight upward trend following a gradual decline after the first stop, generally reflecting the influence of passenger flow, environment, and location factors. Key words: bus line, reliability evaluation, bus-stop weight, information entropy. L'evaluation de la fiabilite d'une ligne d'autobus peut fournir des renseignements utiles sur le rendement des services du reseau d'autobus d'une ville et sur la necessite d'apporter des ameliorations. Ce document presente un modele d'evaluation de la fiabilite d'une ligne d'autobus fonde sur l'entropie informationnelle. Le modele integre l'indice pondere des arrets d'autobus et l'indice de variation de la duree de trajet d'autobus. Afin de mieux determiner la ponderation des arrets d'autobus, six indices multiples ont ete etablis en fonction de trois caracteristiques : la circulation de passagers, les proprietes des arrets d'autobus et l'environnement. Le modele propose a ete applique aux lignes d'autobus typiques a Fuzhou, en Republique populaire de Chine. Les resultats montrent qu'en general les degres de fiabilite des arrets d'autobus pendant la periode de pointe etaient inferieurs a ceux en periode creuse. En outre, en periode de pointe ou en periode creuse, le degre de fiabilite montre une legere tendance a la hausse suivant une baisse graduelle apres le premier arret refletant l'incidence de la circulation de passagers, de l'environnement et des facteurs de localisation en general. [Traduit par la Redaction] Mots-cles: ligne d'autobus, evaluation de degre de fiabilite, ponderation des arrets d'autobus, entropie informationnelle., 1. Introduction With increasing traffic congestion, the development of good bus transit systems has become an important strategy for solving traffic problems. For urban bus transit systems, many studies have [...]

Turbo roundabouts, originating from the Netherlands, have been proven to have safety and operations benefits compared to traditional multilane roundabouts. Turbo roundabouts are gradually being adopted by North American transportation and road authorities. However, no design guidelines have been developed yet per North American practices. Sight distance requirements were not even specifically addressed in the Dutch mature design guidelines for turbo roundabouts. This paper focuses on basic turbo roundabouts, examines stopping sight distance (SSD) characteristics, recommends SSD requirements for three critical locations—circulatory roadway, entry approach, and crosswalk on the exit approach—based on AASHTO and Transportation Association of Canada's (TAC's) SSD guidelines, presents analytical models, and develops design guidelines for the required lateral clearance and intersection clear sight triangles to meet the required SSD. The values of the required SSD at the circulatory roadway and to the crosswalk on the exit approach equal the values for the speeds. The required approach SSD is the same as for any roadway section with the same design speed. The minimum crosswalk setback of a one-vehicle gap of 6.0 m between the queued vehicle and the crosswalk is sufficient to meet the required SSD. The required lateral clearance and intersection clear sight triangles are recommended. The recommended guidelines would help develop future design guides per North American practices and provide a guide to property needs for planning basic turbo roundabouts. Practical Applications: Turbo roundabouts initially built in the Netherlands have gradually attracted North American transportation and road authorities' attention, given their safety and operations benefits. After more than a decade's effort in advancing and promoting turbo roundabouts, the first turbo roundabout was built in the US in 2022. However, design guidelines per North American practices are lacking, such as the required stopping sight distance (SSD). The required SSD at the circulatory roadway and entry approach and SSD to the crosswalk on the exit approach are three critical locations. The values of the required SSD at the circulatory roadway and to the crosswalk on the exit approach equal the values of the travel speeds. The required approach SSD is no different from any roadway section with the same design speed. The minimum crosswalk setback of a one-vehicle gap of 6.0 m between the queued vehicle and the crosswalk is sufficient to meet the required SSD. Sight obstructions should meet the required lateral clearance at the roundabout approach and circulatory roadway due to the curve alignment. Clear sight triangles at the roundabout quadrants should be provided to meet the required SSD to the crosswalk on the exit approach. [ABSTRACT FROM AUTHOR]

Mainline coordinated control is usually based on fixed speed and statistical traffic flow by period. However, in actual operation, the vehicles parked in front of the intersection and the arriving vehicles often fluctuate, and the through-traffic green time is wasted due to phase transition, which leads to mismatches between the signal plans and actual traffic flow requirements, affecting the traffic efficiency of the intersection. To address the above issues, using vehicle–road collaborative control (VRCC), by calculating the phase difference lead time and phase difference of adjacent intersections, the green extension time for the green wave through-traffic phase, and the guiding vehicle speed, the goal of reducing the detention volume of through traffic, reducing the waste of through-traffic green time caused by phase transitions and improving the throughput of through traffic can be achieved. The speed of the green wave traffic flow is increased by guiding vehicles to form saturated platoons during green periods. Finally, PTV VISSIM 4.3 was used for simulation verification, and the results showed that compared to not implementing the control strategy, the average delay on the arterial road was reduced by 85.1%, the average number of stops was reduced by 84.3%, the average travel time was reduced by 34%, and the average queue length was reduced by 62.6%. This significantly improved the efficiency of traffic on the arterial road and effectively reduced congestion. [ABSTRACT FROM AUTHOR]

This study explores the temporal instability and non-transferability of the determinants affecting injury severities of pedestrians struck by motorcycles and non-motorcycles. Using the pedestrian-vehicle crash data in Rawalpindi, Pakistan, over three years (2017–2019), three possible crash injury severity categories (minor injury, severe injury, and fatal injury) are estimated using alternative models to account for unobserved heterogeneity. These are a random-parameters multinomial logit (RP-ML) model with heterogeneity in means and variances and a latent-class multinomial logit (LC-ML) model with class probability functions. Temporal instability and non-transferability in the effects of explanatory variables are confirmed using a series of likelihood ratio tests based on the two alternative models. Various variables are observed to determine pedestrian-injury severities, and the estimation results show significant temporal instability and non-transferability in both RP-ML and LC-ML models. However, several explanatory variables produce relatively temporally stable and transferable effects, providing valuable insights to implement effective countermeasures from a long-term perspective. Moreover, out-of-sample predictions are simulated to confirm the temporal instability and non-transferability. At the same time, the LC-ML models produce higher differences for temporal instability and lower differences for non-transferability compared to the RP-ML model. Understanding and depth comparing the estimation results, likelihood ratio tests, and out-of-sample predictions using alternative models is a promising direction for future research to explore how the observed and unobserved heterogeneity can be estimated in terms of temporal instability and non-transferability. [ABSTRACT FROM AUTHOR]

In areas with significant changes in traffic demand and high vehicle dispersion at adjacent intersections, such as the surrounding roads of large shopping malls and schools, traffic problems are prone to occur. This is due to the unequal signal cycle lengths used at upstream and downstream intersections, which lead to periodic phase offsets as the cycles progress. To address this, we propose a multi-strategy integrated vehicle–road coordinated control method to tackle traffic flow operational issues caused by the offset characteristics of unequal-cycle adjacent intersections. A multi-strategy combined algorithm and control logic is established, which includes downstream intersection coordinated phase green extension, dynamic offset adjustment, and transitional queue speed guidance. The proposed method can substantially minimize the offset from falling into an incompatible threshold, effectively reducing queuing and early arrival of vehicles in the straight-through direction. It enables arriving vehicles to pass through the intersection without or with minimal stopping. Finally, the effectiveness of the method is validated using simulation experiments. A vehicle–road coordinated simulation verification platform was established, and comparative experiments were designed. The results indicate that the multi-strategy combined vehicle–road coordinated control method proposed in this paper, while ensuring the original through capacity for straight movements, can effectively reduce queue lengths, the number of stops, average vehicle delay, and travel time for single-direction straight lanes. This improvement enhances the efficiency of coordinated movements in the unequal–cycle adjacent intersections. [ABSTRACT FROM AUTHOR]

This study proposes a new method to assess the bearing capacity of similar bridges while avoiding the disadvantages of costly static loading tests. First, we present a detailed evaluation of the bearing capacity for a repaired pre-stressed concrete continuous-beam bridge following a ship collision. We have developed a finite element model, modified it, and combined with two other methods to evaluate its bearing capacity. The first method proposed is the bridge design code-based method, where the bearing capacity is assessed using specified design parameters. The second is the field test-based method, where the bearing capacity is evaluated using field tests combined with structural appearance observation. Considering the relative merits of these two methods, a new and improved method for bearing capacity evaluation is proposed and implemented by combining the design code, finite element model, and field loading tests. The innovation and contribution of this paper lie in obtaining modal parameters through a convenient dynamic load test to predict the static behaviour of the bridge structure based on the modified finite element model. Based on the dynamic test results, the static behaviour of the bridge, predicted by the modified finite element analysis, and the appearance test data of the bridge structure, the bearing capacity of the bridge structure is evaluated. [ABSTRACT FROM AUTHOR]

Most existing road infrastructures were constructed before the emergence of automated vehicles (AVs) without considering their operational needs. Whether and how AVs could safely adapt to as-built highway geometry are questions that remain inconclusive, and a plausible concern is a challenge from vertical alignments. To fill this gap, this study uses a virtual simulation to investigate the available sight distance (ASD) of AVs on vertical alignments subject to the current highway geometric design specification and its implications for speed limits. According to the scenario generation framework, several scenarios featuring vertical geometric elements and lidar sensors were created and tested. Moreover, the maximum speed for adequate ASD is calculated to determine the AV speed limit, considering safe sight distance and speed consistency requirements. The results indicate that crest curves are not disadvantaged in ASD compared with either sag curves or tangent grades. Only equipped with multichannel lidar and advanced perception algorithms enabling a lower detection threshold would a level 4 AV be compatible with the as-built vertical alignment with a design speed (Vd) of 100 km/h. However, a level 3 AV can only adapt to the vertical profile with Vd = 60 km/h. The findings of this study should be of interest to the road-oriented operational design domain and support road administrators in regulating AV safe speeds. [ABSTRACT FROM AUTHOR]