Unsafety on two wheels,or social prejudice? Proxying behavioral reports on bicycle and e-scooter riding safety – A mixed-methods study

The use of non-motorized transportation and micro-mobility is increasing in many cities. Bicycle riding and e-scooter use are now more common and affordable than ever. However, users of these devices face certain key issues. These include their own risky behaviors as well as involvement in conflicts with other road users. Self-report data may not adequately capture these behaviors and interactions. Despite this, more objective data (i.e., how third parties perceive these users’ road behaviors) is scarce. Aims: This study aimed to understand whether e-scooter riders have comparable or different riding behaviors than cyclists. This was investigated using a mixed-method study. Methods: This paper is divided into two sub-studies. In Study 1, 950 Spanish non-cyclists and non-e-scooter riders (mean age 31.98 ± 13.27 years; 55.3% female) provided external ratings (proxies) regarding the perceived behaviors of bicycle and e-scooter riders. In Study 2, collective Rapid Assessment Processes (RAPs; n = 23) were used to develop qualitative configurations of some of the key risky behaviors highlighted in Study 1. Results: There were significant differences in the perceived errors and violations rated by proxies for both types of riders (with e-scooter riders perceived as having higher rates of risky behaviors). However, there were also structural differences in the effects of external raters’ risk perceptions, traffic rule knowledge, and traffic incidents with two-wheeled riders on how they rated the behaviors. Conclusion: The results of both studies suggest that external raters’ perceptions provide further understanding of the causes, dynamics, and conflicts related to road behaviors performed by certain groups of road users. This is particularly apparent when there is no clear legislation and information on safe riding in urban areas. In this sense, improving infrastructure could promote safer interactions. Finally, road safety education could focus on promoting safer practices and interactions in order to improve how others perceive riders’ behavior.     

A sleep physiologist's view of the drowsy driver

Drowsy driving is dangerous because of the impairment of driving skills that it causes. Unfortunately, the conceptual basis that underlies much of the multi-disciplinary research on this topic is muddled. The same poorly defined terms, such as fatigue and sleepiness, are used differently by different disciplines and researchers. Some new definitions and concepts are proposed here which may be helpful, as least as a stimulus for discussion by others. Drowsiness, sleepiness and fatigue are distinguished. A new conceptual model of sleepiness is outlined, based on a mutually inhibitory interaction between a putative sleep drive and a wake drive. Sleepiness, defined as sleep propensity, is a function of the relative strengths, not the absolute strengths, of the sleep and wake drives. The measurement of sleepiness requires some new variables such as instantaneous sleep propensity, to be distinguished from either the situational or the average sleep propensity. A subject's instantaneous sleep propensity depends on many variables including his average sleep propensity in daily life, the time of day, the duration of prior wakefulness, the subject's posture, physical and mental activity at the time, and individual differences based on psychophysiological traits. The relationship between dozing at the wheel while driving and crashing the vehicle may not be as straightforward as it appears at first.     

Efficacy of proxy definitions for identification of fatigue/sleep-related crashes: An Australian evaluation

Fatigue/sleepiness is recognised as an important contributory factor in fatal and serious injury road traffic incidents (RTIs), however, identifying fatigue/sleepiness as a causal factor remains an uncertain science. Within Australia attending police officers at a RTI report the causal factors; one option is fatigue/sleepiness. In some Australian jurisdictions police incident databases are subject to post hoc analysis using a proxy definition for fatigue/sleepiness. This secondary analysis identifies further RTIs caused by fatigue/sleepiness not initially identified by attending officers. The current study investigates the efficacy of such proxy definitions for attributing fatigue/sleepiness as a RTI causal factor. Over 1600 Australian drivers were surveyed regarding their experience and involvement in fatigue/sleep-related RTIs and near-misses during the past five years. Driving while fatigued/sleepy had been experienced by the majority of participants (66.0% of participants). Fatigue/sleep-related near misses were reported by 19.1% of participants, with 2.4% being involved in a fatigue/sleep-related RTI. Examination of the characteristics for the most recent event (either a near miss or crash) found that the largest proportion of incidents (28.0%) occurred when commuting to or from work, followed by social activities (25.1%), holiday travel (19.8%), or for work purposes (10.1%). The fatigue/sleep related RTI and near-miss experience of a representative sample of Australian drivers does not reflect the proxy definitions used for fatigue/sleepiness identification. In particular those RTIs that occur in urban areas and at slow speeds may not be identified. While important to have a strategy for identifying fatigue/sleepiness related RTIs proxy measures appear best suited to identifying specific subsets of such RTIs.