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

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

Oral administration of chios mastic gum or extracts in mice: Quantification of triterpenic acids by liquid chromatography-tandem mass spectrometry

Chios mastic gum, the resin obtained as an exudate from the trunk and branches of Pistacia lentiscus L var. chia, is used extensively as a constituent of herbal drugs or functional foods. The oral absorption of its major constituents still remains unclear. In the context of identifying the features of mastic gum that are responsible for either therapeutic effects or effects of nutritional value, a methodology based on high-performance liquid chromatography (HPLC) coupled to tandem mass spectrometry (MS/MS) was developed and applied for the quantification of mastic gum triterpenic acids, 24Z-isomasticadienonic acid (IMNA), and 24Z-isomasticadienolic acid (IMLA) in mouse plasma. The specific compounds were selected based on their biological activity and potential against Helicobacter pylori. Concentrations were determined simultaneously in mouse plasma after oral administration of mastic gum or total mastic extract without polymer (TMEWP) in order to evaluate the role of the natural polymer, poly - myrcene, in the absorption process. Following TMEWP administration in mice, circulating IMNA and IMLA plasma levels were significantly higher (approximately 10-fold) in comparison to IMNA and IMLA plasma levels following total mastic gum administration (CMG), suggesting that the polymer plays a critical role in the absorption process. More specifically following TMEWP administration, Cmax plasma values were 3300±859ng/mL for IMNA and 163±58ng/mL for IMLA. In comparison, following CMG administration, Cmax plasma values were 329±57ng/mL for IMNA and 28±8ng/mL for IMLA. The methodological approaches presented in this study, along with the findings, offer valuable information on the availability of bioactive components following ingestion of mastic and facilitate the uses of mastic either as an ingredient of functional foods or as a herbal drug. © Georg Thieme Verlag KG Stuttgart - New York

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

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

Investigation of speeding and centerline encroachment by motorcycle riders on a 2-lane rural road

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. © 2021, World Scientific and Engineering Academy and Society. All rights reserved