In recent years, motorcycle ownership has significantly increased, particularly in urban areas. Although in developed economies the use of this mode of transport is not so popular, in developing countries it is one of the most widespread modes. Powered two three-wheelers (PTWs) were responsible for 21

The European Union’s path towards zero carbon dioxide emissions for new passenger vehicles necessitates a transitional period in which conventional vehicles coexist with zero-emission alternatives. This shift requires targeted strategies from engineers and policymakers, particularly in the area of road design, to reduce pollution. This study aims to investigate the environmental benefits of converting a two-lane urban roundabout into a turbo-roundabout through a virtual microsimulation approach using PTV VISSIM. The simulated model was calibrated and validated with real-world daily traffic data by properly adjusting the driving behavior parameters and comparing observed and modeled traffic volumes and queues. The Vehicle-Specific Power (VSP) emission method was applied to model, calculate and illustrate emissions by analyzing vehicle trajectories for the examined scenarios. Results show a statistically significant reduction in emissions for nearly all trips, with emissions decreasing by up to 44% across the intersection and its surrounding areas, and up to 23% at the intersection itself. Emissions are largely influenced by trip duration and traffic efficiency, both of which are enhanced by the improved geometric configuration of the case study intersection. These findings highlight that turbo-roundabouts represent an effective, environmentally sustainable design solution for urban intersections.

The impact of cycling-related traffic crashes on public health has increased significantly in recent decades, with cyclists being among the most vulnerable road users. The risk of severe injury in traffic crashes is notably high for cyclists, especially when distracted. Research indicates that distraction while cycling significantly increases the crash risk. This study investigates cycling distraction through a field operational test involving 100 participants. Riders followed a predetermined course while being exposed to external visual and auditory stimuli, including alarms, advertising signs, and car horns. Distraction levels were measured using eye-tracking technology. Data were analyzed by means of descriptive statistics, cluster, and correlation analyses. Our findings showed that auditory stimuli distract a higher percentage of cyclists, while audiovisual stimuli from road-related factors cause longer-lasting distractions. Additionally, five distraction clusters were identified based on stimulus duration. Lastly, it was found that males were more likely to belong to high-distraction clusters, whereas females and daily cyclists were more likely to fall into the lowest-distraction group.

This study explores and evaluates different methodologies for designing the edge-of-traveled-way turning paths at right-angle at-grade intersections, with emphasis on low-speed maneuvers involving large design vehicles. Three geometric approaches are examined as follows: the standard AASHTO configuration, the German RAS-K-1 triple-radius method, and a clothoid-based transition curve design. Simulations using representative design vehicles, conducted under speeds ≤ 15 km/h, are used to assess each method’s performance in terms of spatial efficiency, steering continuity, and lateral clearance. The findings suggest that while the AASHTO asymmetric compound curve offers an effective balance between clearance and compactness, clothoid curves may improve transition smoothness and provide an alternative option for designing the edge-of-traveled-way turning paths at right-angle at-grade intersections.

Over the past several decades, there has been a significant increase in the influence that bicycle-related traffic events have on public health. A particularly susceptible category of drivers are cyclists. Cycling raises the possibility of getting into a car accident and having severe injuries as a result. According to the research, there seems to be a substantial correlation between being distracted and the chance of getting into a traffic accident when bicycling. Despite the difficulty of driving, there is a serious risk to transportation safety when drivers focus on with anything other than driving. Understanding the phenomenon of driver distraction, gathering information vital to the development of efforts by the many stakeholders to tackle the issue, and utilizing the results as a foundation for further research are the goals of this article. A summary of recent studies on driver distraction is given, with a focus on distraction brought on by external factors. The phenomenon of distracted bikers is then investigated through a field operational test conducted in Volos. In this study, fifty cyclists were given instructions to bike a predefined course while being subjected to external auditory and visual stimuli. Data analysis and studies indicate that cyclists who drive while distracted provide a significant safety concern that should definitely be considered.

Driver distraction is a growing problem, as it seems to be an important cause for several road accidents. This study was conducted with the aim to look into the contributory factors that may cause a driver’s distraction, some of which are the use of mobile devices, fatigue of the driver, consumption of food and beverages and smoking while driving. In this paper, we report on the findings of an online questionnaire survey in which 1214 Greek drivers willingly participated in a study that aspired to unveil drivers’ perspective on their own driving habits. The data collection tool was a questionnaire consisted of 27 questions and divided into seven parts. The first questions referred to participants’ profile such as gender, age, educational level and years of holding a driving license. The next questions focused on participants’ mobile phone use in their everyday activities and mobile phones use while driving, and on participants’ consumption of food, beverages and smoking during driving. Further questions examined driver’s fatigue and its frequency, the impact of driving with passengers in the vehicle and the extent to which the interaction with them affects a driver’s attention. Finally, participants were asked to grade their personal and other drivers driving skills and behavior. This survey can contribute to the improvement of road safety, as the findings help us quantify the negative effects of drivers’ habits that contribute to distracted driving and supports that the drivers should be better trained and authorities should pay more attention in this situation.

Contemporary urban planning models include urban trail paths. These are paths that create active transportation corridors within a city’s built environment, providing more sustainable travel, especially for short trips. The benefits of their use are plentiful, including improvements in commuters’ health, reductions in energy footprint, and socio-economic benefits for the entire society. In modern urban planning approaches such as the “15-minute city”, urban trail paths serve as connectors, facilitating access to amenities beyond the close-proximity concept of a “neighborhood”. They act as a way of connecting residents to other 15-minute cities/neighborhoods via safe routes, reducing extensive car use. Micromobility constitutes a novel approach to short trips with proven results. This paper explores the possibility of introducing micromobility as a means of connecting 15-minute cities/neighborhoods through urban trail paths. Through a literature review, an analysis is conducted of the opportunities arising from the introduction of micromobility, as well as on the factors influencing its sustained use in urban mobility and the public realm.

The current paper presents the results of a questionnaire survey which examines the trail path usage conditions on Peranthi Hill in Arta, a medium-sized city in northwestern Greece. The key element of the survey is the detailed mapping of the suburban trail path network of the city, and it focuses on questions about the types of activities of people who walk or bike on the trail paths and the day, time, duration and distance of their trips, as well as their equipment (bicycles, clothes, shoes, etc.). Further questions focus on maintenance and safety issues (e.g., security, guarding, cleanliness) and infrastructures which are considered necessary in order to improve the trail paths’ environment and their use. Taking into consideration that several routes are being developed on Peranthi Hill, with distinct differences in their layouts, the preferred layout is explored in relation to each activity selected by the users. The results of the questionnaire survey, and the cluster analysis specifically, aim to address these issues and assist stakeholders and policymakers in improving the trail paths in terms of their utility and usability level.

The utilization of conclusions from the data analysis of road traffic accidents is of high importance for the development of targeted traffic safety measures, which will effectively reduce the rate of road traffic accidents, thus promoting road safety. Considering the problems of time and money, it is not practical to improve road safety in all the places where road traffic accidents occur. Therefore, the process of identifying accident-prone locations, known as black spots, is a cost-effective and efficient way to analyze the causes of road accidents and reduce them. Identifying black spots is an effective strategy to reduce accidents. The core methods that may be used in the process of identifying the black spots of a road network are the sorting, grouping, and accident prediction methods. However, in practice, it is easy to overlook certain factors that significantly contribute to defining and characterizing a spot on the road network as black. Therefore, suggestions to carry out projects required to reduce security risks shall not be based on the above methods. Machine learning algorithms that in recent years have been widely used in the field of predicting a road traffic accident cover these weaknesses. They can effectively classify data sets and make a connection between factors and the severity of events. Machine learning algorithms include classification, regression, clustering, and dimensionality reduction. In this work, a study was conducted on road traffic accidents that took place on the national and provincial network of Northern Greece from 2014 to 2018, with the aim of determining the black spots. The study provided the general public access to a database of black spots on the road network of Northern Greece. At the same time, it created a point of reference for the recognition of the points in question located on the entire road network, and selected a black spot determination model, after having compared specific measures to determine the quality of a model, which resulted from the application of a logistic regression and machine learning algorithms.

Undoubtedly, road accidents are a public health problem, the impact and importance of which have increased in recent decades. Road safety data have systematically shown how cyclists are very vulnerable to being involved in a car accident and suffering serious injuries resulting from it. Furthermore, although the data are still very limited, in addition to the other human factors involved in cycling accidents, distraction when using the bicycle seems to contribute significantly to the road risk of riders. It is well known that driving is a complex process that requires the simultaneous existence of physical, mental and sensory abilities. Despite the complexity of driving, it is observed that drivers deal with things that are irrelevant to the driving task. And this is a huge problem in transport safety, the distraction of the driver. With the growing number of portable devices as well as the electronic help and entertainment systems offered to the driver, the sources of distraction are constantly increasing. The purpose of this study is to understand the phenomenon of driver distraction and to export results, important for the progress in dealing with the phenomenon by the various agencies that can be used as a basis for further research. More specifically, a summary of the recent literature on driver distraction is made, focusing specifically on the distraction of drivers, both by technological means and by external factors. Finally, a methodological approach is applied to the phenomenon, and in particular to the distraction of the bicycle driver in the urban environment, which includes the realization of an experiment in real conditions in the city of Volos. The research involved 15 drivers, who were asked to perform a specific route by cycling and following specific instructions through a navigator. The data collected were analyzed and showed that the phenomenon of driver distraction is real and is a high-risk factor.

Motorcycle riders are considered as one of the most vulnerable road users group worldwide. This is supported by numerous statistics which reveal that despite the reduction of vehicular fatalities over the last 15 years, the lesser improvement is observed in motorcycle fatal accidents compared to the other road users, either vulnerable or not. Speed and lane departure have been documented as significant contributory factors which precipitate the occurrence of motorcycle accidents. Many researchers attempted to identify and analyze the reasons behind this fact by conducting naturalistic riding studies using instrumented motorcycles and a relatively small number of volunteers. The recent development of multifunctional GPS devices of high positional and speed accuracy has assisted in this direction by allowing the planning of field measurements in a cost and time-effective manner. A similar practice has been adopted to the present study which aims to record and process the recorded data of a mid-scale naturalistic riding study in a two-lane rural road segment in an effort to investigate whether the motorcycle riders follow the posted speed limits. Apart from the investigation of the traveling speed, the high accuracy of the recorded positional data permitted us to compare the trajectory of the riders with the one that is determined by the theoretical model. The latter assumes that the road users travel along the midline of the travel lane and hence the curvature of the horizontal alignment coincides with the actual trajectories. The findings of the paper reveal that the riders do not comply with the posted speed limits to a large extent and follow a trajectory different from the theoretical one. Both findings pose a great risk to motorcycle riders’ safety, which strengthening is the main contribution of the present paper.

The development of operating speed models has been the subject of numerous research studies in the past. Most of them present models that aim to predict free-flow speed in conjunction with the road geometry at the curved road sections considering various geometric parameters e.g., radius, length, preceding tangent, deflection angle. The developed models seldomly take into account the operating speed profiles of motorcycle riders and hence no significant efforts have been put so far to associate the geometric characteristics of a road segment with the speed behavior of motorcycle riders. The dominance of 4-wheel vehicles on the road network led the researchers to focus explicitly on the development of speed prediction models for passenger cars, vans, pickups, and trucks. However, although the motorcycle fleet represents only a small proportion of the total traffic volume motorcycle riders are over-represented in traffic accidents especially those that occur on horizontal curves. Since operating speed has been thoroughly documented as the most significant precipitating factor of vehicular accidents, the study of motorcycle rider's speed behavior approaching horizontal curves is of paramount importance. The subject of the present paper is the development of speed prediction models for motorcycle riders traveling on two-lane rural roads. The model was the result of the execution of field measurements under naturalistic conditions with the use of an instrumented motorcycle conducted by experienced motorcycle riders under different lighting conditions. The implemented methodology to determine the most efficient model evaluates a series of road geometry parameters through a comprehensive literature review excluding those with an insignificant impact to the magnitude of the operating speeds in order to establish simple and handy models.

The bicyclist’s behavior under different road and build environment in the road network of Volos, a mid-sized Greek city, is recorded and analyzed. The developed methodology was based on the use of GPS technology embedded in instrumented vehicles for the acquisition of behavioral and performance data parameters such as speed, position, and lateral/longitudinal accelerations. These parameters are crucial for two-wheeler road users compared to the four-wheeler. This study concludes that it is feasible to record bicyclists’ speed and acceleration profiles with accuracy and speed, and moreover supports that there is a strong indication that a bicycle is a rather controllable and predictable transport mode. However, the generalization of the conclusions drawn in a wider proportion of road users demands the conduction of more experiments including a greater number of participants and road sections.

This study examines the relationship between commuters’ travel behavior and sustainable transport modes infrastructure in the city of Volos (a mid-sized Greek city) during the years of economic crisis (2008–2017). The scope of this survey was to study how the travel behavior has changed during the examined years and if there is a preference to sustainable transportation. The study was based on a questionnaire survey conducted on a random sample of 293 individuals through personal interviews in the year 2017. The questionnaire was formed of 32 questions divided into four parts. This study supports that citizens have changed their travel behavior in the city during the examined years, favoring the use of sustainable transport modes. The recovery of Greek economy from economic crisis should not be an excuse to increase use of private vehicles but an opportunity to change commuters travel behavior in urban areas and promote sustainable transport modes with relative societal, environmental and economic benefits.

Promotion of cycling can improve the sustainability level of a city or an urban area. This study presents a methodology that audits the bikeability level of the urban road environment across three selected routes in the city of Volos, Greece. This methodology is a useful toolkit in order to evaluate and improve the bikeability level of the urban road environment and also evaluate existing bikeways. Four suitably trained auditors rode their bikes and evaluated the bikeability level using an audit tool in order to audit specific features that influence bicycling suitability across the road segments and intersections of the selected routes. Furthermore, the auditors graded specific features of the road environment in order to set a bikeability score for each tested route. Finally, this study concludes that the bikeability level of the selected routes was moderate and certain actions are necessary in order to be improved.

The paper examines the relationship between sustainable transportation and the reduction of perceived traffic noise levels in the cities of Athens and Thessaloniki. The research was based on a questionnaire survey conducted on a random sample of 490 participants through personal interviews in the year 2016 (271 in Athens and 219 in Thessaloniki). The questionnaire was formed of 18 questions divided into two parts. In the first part (questions 1÷6), the participants stated their demographic data and personal income comparing the years 2008 (before the economic crisis in Greece) and the year 2016 (crisis in progress). In the second part (questions 7÷18), the participants stated the change of traffic noise levels comparing the years 2008 and 2016, the influence of traffic noise in route and transport mode choice and their willingness to increase walking and bicycling due to reduction of traffic noise. Furthermore, they stated the perceived level of traffic noise in the street they resident during day and night time, their awareness of traffic noise negative impacts on public health and their willingness to change their residential area for a quieter but more expensive one. Moreover, they stated their awareness of the sustainable transport modes positive impacts in traffic noise reduction and their willingness to pay an additional tax in order to fund relative sustainable transportation and traffic noise reduction projects in their cities. The present economic crisis in Greece can be an opportunity to change the commuters travel behavior and promote sustainable transportation.

Two of the most prevalent calculation methods of road projects' earthworks in terms of robustness and computational easiness are the methods of the average end-area and applicable lengths. The present study, focuses on the second method and specifically, compares the classical calculation approach to a simplified approach. The classical calculation approach of the applicable lengths computes the earthworks of a cross section (n) by multiplying its surface area with the respective applicable lengths, which is the sum product of 1/4 or 1/2 of the distance with the prior cross section (n-1) and 1/4 or 1/2 of the distance with the following cross section (n+1), depending on whether the prior/following cross section is of the same type (cut or fil) with the section (n). The proposed simplified approach computes the earthworks of a section, by considering that the applicable lengths is always equal to the mean value of the distances with the prior and the following cross section, without checking the type of the prior/following cross section. To validate the performance of the simplified approach the earthworks' volumes of a number of projects was computed with the classical and simplified approach and the results were compared with the exported results from a road design software where volume measurements were taken every one meter. As a first step towards the validation of the approach, nine projects with different territories were investigated. Then, projects with different slope and standard deviations of the height differences between the road profile and the terrain profile were further investigated. Finally, in 45 road projects with the same horizontal alignment but different longitudinal profile, the earthworks' volumes were calculated for three different typical cross sections. The results that arouse from each step of the analysis, indicate that both approaches produce very similar results, regardless of the changing parameters.

In this paper, the evolution across different time periods of coupling and decoupling relationships between transport-related energy consumption and gross domestic product (GDP) for the EU-28 member countries is analysed. Focusing on the period before and after the economic crisis of the year 2008, it is noticeable a differentiation of the relation between economic growth and transport-related energy consumption, as after the economic crisis the vast majority of countries have passed the threshold of coupling and are subjected to a form of decoupling. This new reality creates a significant opportunity for transport activities and for travel habits to enter into a continuous process of rationalisation and reduction of both energy consumption and other transport-related harmful effects to the environment. It is a political and institutional challenge to maintain the observed decoupling, by strengthening and encouraging the green mobility, the environmentally friendly and efficient mobility, which is one of the greatest tasks of the future.

In this paper it is surveyed whether the installation of countdown timers to the traffic lights of an urban intersection can efficiently contribute to the increase of both road safety and traffic capacity of the converging streets. A complete case-study is conducted in the city of Komotini (67,000 inhabitants, north-eastern Greece). By using video monitoring devices and the software Captiv L2100 the behavior of 14,946 drivers in two intersections in the center of the city under study is monitored. The analysis focused on their behavior just before the change of the traffic lights to green and red ones. It is concluded that installation of such devices leads to reduction of delays and increase of traffic capacity. However, concerning safety, drivers have a contradictory behavior. They respect the coming of the red light, while they begin moving before the green light is on. Under these findings, it is suggested to use the specific device before the light turns to red, but not before the light turns to green.