Investigation of Motorcycle Trajectories in 2-lane Horizontal Curves

-Most of the road design guidelines assume that the vehicles traverse a trajectory that coincides with the midline of the traffic lane. Based on this assumption the thresholds of various features are determined such as the maximum permissible side friction factor. It is therefore important to investigate the extent to which the trajectory of the vehicles is similar to the horizontal alignment of the road or substantial differences exist. To this end, a naturalistic riding study was designed and executed with the use of an instrumented motorcycle which measured the position of the motorcycle with great accuracy in a rural 2-lane road segment. The derived trajectories were then plotted against the horizontal alignment of the road and compared with the 3 consecutive elements which form a typical horizontal curve i.e., the entering spiral curve, the circular curve, and the exiting spiral curve. Linear equations were developed which correlate the traveled curvatures with the distance of each horizontal curve along the road segment under investigation. The process of the data revealed that the riders differ their trajectory compared to the alignment of the road. However, in small radius horizontal curves is more likely to observe curvatures that are similar to the geometric one. Moreover, the riders perform more abrupt maneuvres in the first part of the horizontal curves while they straighten the handlebars of the motorcycle before the end of the curve. The present paper aims to shed light on the behavior of motorcycle riders on horizontal curves and hence to contribute to the reduction of motorcycle accidents, particularly the single-vehicle ones. © 2021, World Scientific and Engineering Academy and Society. All rights reserved

Investigation of speed and trajectory of motorcycle riders at curved road sections of two-lane rural roads under diverse lighting conditions

Introduction: Vehicular accidents at horizontal curves are over-represented compared to accidents that occur at tangent sections. Investigations have been conducted aimed at identifying the major causes that result in higher accident risk, both in terms of severity and rate, at curved road sections. Excessive or abrupt changes in speeding and improper vertical position are cited as major factors of lane departure, whereas other factors (either human or environmental) have also been documented. However, most research involves 4-wheel vehicles rather than other modes of transport that behave differently. More specifically, while motorcyclist fatalities occur more frequently than passenger vehicles, when accounting for vehicle distance traveled only a limited number of research studies address their behavior at curved road sections. Method: This paper presents the findings of field operational tests carried out by motorcyclists along two-lane rural roads with a wide range of horizontal curves using an instrumented motorcycle. Key objectives of the research included the conditions under which the motorcyclists differentiate their trajectory in regards to the direction of the horizontal curves, the correlation between the trajectory and the geometry of the road, and the impact of the lighting conditions on riders’ behavior. Results: The research showed that motorcyclists tend to ride closer to the centerline of the road, neglect the hazards associated with dim lighting conditions, and maintain constant speed in the left hand and the right-hand horizontal curves. © 202

Recording and Evaluation of Motorcyclists’ Distraction of Attention in Urban Areas

Over the last years, distracted driving constitutes a considerably increasing road safety problem with disastrous results and it possesses a leading position among the accidents causes. The present study deals with motorcycle users’ distraction due to out of the vehicle factors. Considering exterior factors as the most significant, we can group them in four categories: built roadway, situational entities, the natural environment, and the built environment. All these contribute to the setup of a very dangerous environment by increasing driver’s distraction and inattention. This research is based on a medium scale experimental procedure which took place in urban areas in Greece. The distraction of the motorcyclist’ attention is evaluated via a continuous recording of his gaze which acts as the main indicator regarding driver’s performance. The main objective of this paper is to find out and evaluate the main factors of distraction of motorcyclists’ attention in urban road segments and intersections. The results of this type of research procedures are very useful as a tool to encourage the adaptation of more precise regulations with regard to the road infrastructure, the placement of roadside elements, etc. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG

Survey and Design Consistency Evaluation in Two-Lane Rural Road Segments

-The present research proposes a time and cost-effective methodology to survey and perform a design consistency evaluation in two-lane rural road segments. The implementation of the proposed methodology carried out in Central Greece and more particularly along the national road Volos-Karditsa, from the local community Mikrothives up to the entrance of the Volos municipal unit. The road survey methodology, the process of creating the terrain model as well as the cross-check between the designed road with the requirements included in the Greek Road Design Guidelines Manual-Chapter X, are analytically presented. Similar checks are also performed for the sight distance throughout the road segments aiming to enable the rehabilitation of existing rural roads and enhance their safety level. The design of the road was followed by the execution of an experiment with the participation of a motorcycle rider aiming at the recording of his trajectory throughout the road which was then compared with its geometry. The experiment carried out by exploiting an instrumented vehicle and GPS technology. Several conclusions were drawn regarding the encroachment of the centerline and the deviation from the theoretical trajectory in the middle of the travelled way. Subsequently, the proposed methodology provides a reliable and simple solution of surveying and evaluating a 2-lane rural road in safety terms. © 2022, World Scientific and Engineering Academy and Society. All rights reserved

Sustainable Travel Behavior and Perspectives on the Daily Commute – A Questionnaire Survey in a Typical Mid-Sized Greek City

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. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG

Comparative analysis of motorcyclists’ gaze behavior in different road environments

-While car drivers consist the vast majority of road users, motorcycle drivers are considered among the most vulnerable ones with significant participation in accidents. The present study investigates the role of elements that permanently exist in the road environment and affect motorcyclist’s behavior since their usefulness requires visual contact between them and the rider during a certain period of time. Therefore, on such an occasion the riders do not monitor the road ahead which is considered as a fundamental driving task and hence the visual search and scan is not directed to the frontal view. The main objective of this paper is to identify and evaluate certain aspects of motorcyclists’ behavior influenced by exterior factors, such as observation of vertical signage or advertisement signs, by using naturalistic data. Motorcyclist’s visual behavior is evaluated via a continuous recording of his gaze, which acts as the main indicator regarding the rider’s performance, with the use of special equipment under naturalistic riding conditions. The selection of a naturalistic method permits continuous data recording, producing real-time data. Thus, the results are reliable and valid to the maximum possible extent. This research is based on a medium-scale experimental procedure that took place in three different road sections in Western Greece. A number of 11 motorcyclists participated in the study. The present research may be used as a tool to improve road infrastructure and to identify attitudes that pose a risk to rider’s safety aiming to the creation of a safer road environment, which will lead to less fatal and serious accidents. © 2021, World Scientific and Engineering Academy and Society. All rights reserved

A Methodology to Investigate Powered Two-Wheeler Rider’s Comfort over Road Sections with Skew Superelevation

The proper surface water drainage not only affects vehicle movement dynamics but also increases the likelihood of an accident since inadequate drainage is associated with potential hydroplaning and splash and spray driving conditions. Nine solutions have been proposed to address hydroplaning in sections with inadequate drainage e.g. augmented superelevation and longitudinal slope, reduction of runoff length, and skew superelevation. The latter has been extensively implemented in highways recently, enhancing the safety level in the applied road segments regarding the effective drainage of the rainwater. However, the concept of the skew superelevation has raised concerns regarding the level of driver’s comfort when traveling over skew superelevation sections particularly with high speeds. These concerns were alleviated through the concept of the round-up skew superelevation which reduces both the lateral and the vertical acceleration imposed on the drivers and hence, improves comfort and traffic safety. The present study investigates the behaviour of power two-wheeler riders since they are susceptible to any changes on the pavement surface and therefore a comparison between the traditional superelevation practice and the skew superelevation concept is of paramount importance. The methodology is based on the utilization of sophisticated software to design the model of the road for several values of longitudinal slopes. Based on the values of the slopes and the use of mathematical equations, the accelerations imposed on the wheel of the motorcycle were calculated. Since the final aim of the study is the influence of the skew superelevation to the rider, it was deemed necessary to convey the calculated accelerations from the wheel to the rider. That was accomplished by implementing the quarter car suspension model adjusted to the features of two-wheeler vehicles. Finally, the accelerations derived from this process evaluated according to specific thresholds based on the literature which correspond to certain levels of comfort. The most important conclusion drawn is that the comfort of the riders is not dependent to a great extent on the form of the road gradient because the vertical acceleration imposed on the riders took similar values regardless of the value of the longitudinal slope. © 2021, World Scientific and Engineering Academy and Society. All rights reserved