Cyclist support systems for future automated traffic: A review

Interpreting the subtleness and complexity of vulnerable road user (VRU) behaviour is still a significant challenge for automated vehicles (AVs). Solutions for facilitating safe and acceptable interactions in future automated traffic include equipping AVs and VRUs with human-machine interfaces (HMl.s), such as awareness and notification systems, and connecting road users to a network of A Vs and infrastructure. The research on these solutions, however, primarily focuses on pedestrians. There is no overview ofthe type of systems or solutions supporting cyclists in future automated traffic. The objective ofthe present study is to synthesise current literature and provide an overview ofthe state-ofthe-art support systems available to cyclists. The aim is to identify, classify, and count the types of communicative technologies, systems, and devices capable of supporting the safety of cyclists in automated traffic. The overall goal is to understand A V-cyclist interaction better, pinpoint knowledge gaps in current literature, and develop strategies for optimising safe and pleasant cycling in future traffic environments with AVs

Prevalence of psychoactive substances in Dutch and Belgian traffic

Objective: The purpose of this study was to compare the prevalence of psychoactive substances in general traffic in The Netherlands and Belgium. Method: Randomly selected car drivers and drivers of small vans in six police regions in The Netherlands and five police regions in Belgium were included between January 2007 and August 2009. Blood and oral fluid samples were analyzed for 23 substances, including ethanol (alcohol), by means of ultra performance liquid chromatography tandem mass spectrometry or gas chromatography mass spectrometry analysis. Samples were weighted according to the distribution of traffic over eight 6-hour periods. Substance groups were categorized in five mutually exclusive classes: single alcohol use, single illicit drug use, single medicinal drugs use, multiple drug use (including drugs from two or more separate substance groups but excluding alcohol), and drug use (either single or multiple) in combination with alcohol. Results: In total, 7,771 drivers (4,822 in The Netherlands and 2,949 in Belgium) were included in the study. In Belgium, the prevalence of single alcohol (6.4%) and single medicinal drugs (3.0%) was much higher than in The Netherlands (2.2% and 0.6%, respectively), whereas the single illicit drugs were more common in Dutch traffic (2.2%) than in Belgian traffic (0.6%). Compared with the estimated prevalence of psychoactive substances in the general driving public in Europe, the prevalence in Belgium (10.7%) was greater than the European average (7.4%), and the prevalence in The Netherlands was below the European average (5.5%). Conclusions: The observed prevalence of psychoactive substances varies largely between The Netherlands and Belgium. Probable reasons for the differences are the higher level of alcohol enforcement in The Netherlands and nonresponse bias in the Belgian study (for illicit drugs in particular). Furthermore, cultural differences and variances in prescription policy could also be influential

An experiment on the lateral steering behaviour of cyclists on narrow bidirectional cycle tracks

Cycling contributes to public health because it requires physical effort [1] and offers economic and environmental advantages over motorized transport [2]. However, 41,000 cyclists die every year in traffic crashes, 3% of the total worldwide [3]. Most fatal bicycle crashes are collisions with motor vehicles. Severe injuries among cyclists, however, are mostly due to single bicycle crashes and their numbers are increasing [4, 5]. An international review showed that the share of hospitalised casualties due to single-bicycle crashes varied from 3% to 41 % of the total number of hospitalised casualties [ 6]. ... The aim of the present study is to investigate the relationship between cycle track width and lateral position. We conducted an experiment in which the cycle track width was manipulated to determine its effect on lateral position. The results have been compared with previous findings from literature. [From: Introduction

The use of navigation systems in naturalistic driving

Objective: In this study, we assessed the use of portable navigation systems in everyday driving by applying in-vehicle naturalistic driving.Method: Experienced users of navigation systems, 7 females and 14 males, were provided with a specially equipped vehicle for approximately 1 month. Their trips were recorded using 4 cameras, Global Positioning System (GPS) data, and other sensor data. The drivers' navigation system use data were coded from the video recordings, which showed how often and for how long the system was activated and how often and for how long a driver operated the system.Results: The system was activated for 23% of trips, predominantly on longer and unique trips. Analyses of the percentage of time for which the speed limit was exceeded showed no evidence of differences between trips for which the navigation system was used or not used. On trips for which the navigation system was activated, participants spent about 5% of trip time interacting with the device. About 40% of interacting behavior took place in the first 10% of the trip time, and about 35% took place while the car was standing still or moving at a very low speed; that is, 0-10km/h.Conclusion: These results shed light on how and when drivers use navigation systems. They suggest that although drivers regulate their use of such systems to some extent, they often perform risky tasks while driving.</p

Behavioural effects of Advanced Cruise Control Use

&nbsp;In this study, a meta-analytic approach was used to analyse effects of Advanced Cruise Control (ACC) on driving behaviour reported in seven driving simulator studies. The effects of ACC on three consistent outcome measures, namely, driving speed, headway and driver workload have been analysed. The indicators of speed, headway and workload have been chosen because they are assumed to be directly affected by the ACC support, their relationship with road safety is reasonably established and they are the most frequently used outcome measures in the sample of analysed studies. The results suggest that different operational settings of ACC that are important for the level of support provided by the system, are significant for the effects ACC have on various aspects of driving behaviour, i.e. on mean driving speed and mean time headway. The obtained effect sizes clustered in two groups, with more intervening ACCs having the effects of an increased driving speed and decreased mean time headway. These results are further discussed in the context of road safety, especially in the context of behavioural adaptation

Comparing a driving simulator to the real road regarding distracted driving speed

Relative and absolute validity of a driving simulator were assessed regarding effects on mean speed and speed variation during distracting secondary tasks, and normal driving. 16 participants drove the same route four times, twice in a simulator and twice in the real world. They performed way finding tasks, using either a paper map or a route guidance system, and mobile phone conversation tasks. Furthermore, driving without secondary tasks on other road segments in the two methods was compared. As both mean speed and standard deviations of speed were not equivalent, absolute validity could not be established. However, as effects found in the experimental conditions varied in the same directions, evidence for relative validity was provided. It is concluded that driving performance regarding speed under distracting conditions may validly be researched in the driving simulator employed here

The Adaption Test: The Development of a Method to Measure Speed Adaption to Traffic Complexity

To monitor novice driver performance in the first years of solo driving, a test aimed at assessing speed adaptation to the traffic situation was developed and evaluated. The Adaptation Test consisted of 18 traffic scenes presented in two (almost) identical photographs, which differed in one single detail, increasing the situation’s complexity. The difference in reported speed between the two pictures was used as an indication of drivers’ adaptation of speed to the complexity of the traffic situation. A previous study showed that novice, unsafe and overconfident drivers, as identified in an on-road driving assessment, performed worse on the Adaptation Test (i.e. less often reported a lower speed in the more complex situation). The analysis of new data in this paper shows no correlation between performance on the Adaptation Test and self-reported crashes, and that after two years, experienced drivers had improved their performance on the Adaptation Test just as much as novice drivers

Overestimation of Skills Affects Drivers’ Adaptation to Task Demands

Inadequate self-assessment, and specifically, overestimation of skill, results in insufficient adaptation to task demands, which can manifest itself on different levels of the driving task. A total of 130 drivers (83 novice and 47 experienced drivers) participated in an on-road driving assessment. Their performance in this assessment (i.e., fail or pass) was compared to the participants’ reported confidence in their driving skills (i.e., high or low confidence), resulting in three calibration groups: a) well-calibrated drivers (reported confidence matched performance on assessment), b) overconfident drivers (high confidence but failed assessment) and c) insecure drivers (low confidence but passed assessment). Furthermore, participants completed a questionnaire which focused on choices made on the strategic and manoeuvring level of the driving task. No significant difference was found between the calibration groups for the strategic level. Overconfident drivers reported significantly more violating behaviour than the well-calibrated and the insecure drivers. At the manoeuvring level, overconfident drivers showed significantly less instances of adaptation to traffic complexity. In conclusion, the current study suggests that overconfidence is related to inadequate adaptation to task demands