2022
Abstract
Background Electrically assisted bicycles (e-bikes) have become increasingly popular and may facilitate active commuting and recreational cycling.
Objective To evaluate the physical activity levels and usage characteristics of e-bikers and conventional cyclists under real-world conditions.
Methods We conducted a prospective observational study in Germany to examine the effects of e-biking compared with conventional cycling on reaching the World Health Organization (WHO) target for physical activity-at least 150 min of moderate-to-vigorous physical activity (MVPA) per week. Study participants (1250 e-bikers and 629 conventional bike users) were equipped with activity trackers to assess the time, distance and heart rate during cycling over four consecutive weeks. Questionnaires were used to assess any traffic accidents incurred over 12 months.
Results The proportion of participants reaching 150 min of MVPA per week was higher for conventional bike users than for e-bike users (35.0% vs 22.4%, p<0.001). In a multiple regression model, the odds of reaching the physical activity target were lower for e-biking than for conventional biking (OR=0.56; 95% CI 0.43 to 0.72) with age, sex, comorbidities and bike usage patterns as confounding factors. No significant differences were observed between bike groups for traffic accidents, yet when controlled for cycling time and frequency of cycling e-bikers had a higher risk of a traffic accident (OR=1.63; 95% CI 1.02 to 2.58).
Conclusion E-bikes are associated with a lower probability of reaching WHO targets for MVPA due to reduced duration and a reduced cardiovascular effort during riding. However, e-bikes might facilitate active transportation, particularly in older individuals or those with pre-existing conditions.
Abstract
Exceeding the potential coefficient of friction between the road surface and tires continues to pose a major safety risk. While systems are now being developed that can estimate the current friction potential quite reliably, the question arises as to the best way to communicate this information to the driver*. This and other questions regarding the usefulness of a friction warning are answered in this project. In the course of this project, the benefits of a friction coefficient warning for goods vehicles were investigated. By means of a test person study in the driving simulator of the Technical University of Berlin, driving behavior could be determined which would have positive effects in the event of a slippery road accident. The study was initially based on literature research, which revealed findings on the state of the art of driver assistance systems as well as insights into research into the design of warnings. Numerous details about the safety potential, the offerings of the various manufacturers, legislation and other aspects of driver assistance systems were explored, while cognitive models and the effects of warnings on a test person were examined for the design of warnings. Consequently, it was possible, together with a panel of experts and preliminary studies on the design of the different smoothness icons, to work out a scientifically sound warning strategy consisting of acoustic signals, voice information and graphic displays on a head-up display. At the same time, an analysis of accidents involving heavy goods vehicles with reduced traction provided an overview of the accident situation for N3 trucks. For this purpose, the data from the GIDAS accident database was examined and a representative random sample of accidents in which reduced traction could have played a role was drawn up. Two scenarios were considered: Rear-end collisions in which the truck collides with another vehicle, and driving accidents in which the truck driver loses control of his vehicle. This accident analysis then formed the basis for the scenario design of the test subject study in the driving simulator. Critical driving scenarios, blind bends and hill climbs and the end of a traffic jam behind a hilltop, each paired with rain, heavy rain or fog and the varying friction coefficient of the road, were presented in the driving simulator together with the warning strategy. In the test subject study, motor vehicle drivers drove through the prepared simulations, with the experimental group receiving the slippery road warning and the control group driving through the same simulation without a warning. The main questions asked were whether the drivers with the warning system adapted their behavior (especially their speed) to the road conditions and whether the drivers with the warning system showed better driving performance in hazardous situations compared to drivers without the warning system. The study also investigated how the drivers assessed the criticality of the driving situations and how the drivers rated the warning strategy. In summary, the study showed that the test subjects with a warning adapted their driving behavior better to the slippery road situation than those without a warning. The former reduced their speed significantly earlier and more strongly. The developed warning strategy was rated as positive and helpful and was accepted by the test subjects with a high level of acceptance. Due to the corona pandemic, the sample size of the test subjects was smaller than originally planned, which must be taken into account for the results. In the final part of this project, the specific benefits of ice warning systems for trucks in relation to accidents were analyzed. With the knowledge of the effect of an ice warning system on the driving behavior of truck drivers, the truck accidents from the GIDAS database could be re-simulated by a forward reconstruction in order to determine what influence the ice warning system would have had on the accident. The analysis showed, among other things, that an ice warning system for trucks could be used in 12% of all accidents. Assuming an average reduction of 9.6 km/h in the speed of truck drivers at 80 km/h due to the ice warning system, almost 30% of collisions involving single-vehicle accidents or accidents involving another vehicle would have been avoided for both trucks and other vehicles involved in the collision. Furthermore, more than half of the trucks and other vehicles involved in collisions would have had lower collision severities. Using injury risk curves, it was possible to show that the lower collision severities significantly reduced the risk of suffering serious or more serious injuries. In the case of truck accidents with pedestrians, two of the nine accidents analyzed would have been avoided and seven accidents would have had the potential to reduce the severity of injuries to pedestrians due to the lower collision speed of the truck. * Gender disclaimer: For reasons of better readability, the generic masculine is used in this report. Female and other gender identities are explicitly included where necessary for the statement.
2021
Abstract
Analysis of the characteristics and accident history of pedelec riders
The increasing popularity of pedelecs is reflected in the annual rise in sales figures. The number of pedelec accidents recorded in official accident statistics is rising at a similar rate, so that the issue of road safety for pedelec riders is becoming increasingly important. Previous research has neither provided a representative picture of the user group nor a holistic picture of their accident history. Three different methodological approaches were therefore chosen in this study in order to describe the user group of pedelecs and their accident history. For the first time, the representative survey provides a broad overview of the personal and vehicle-related characteristics of pedelec riders in Germany, their riding and usage behavior, possible problems in handling the pedelec and accidents experienced within the past three years (n = 775). The two accident analyses - a clinic survey of pedelec riders involved in accidents (n = 39) and an analysis of the pedelec accidents included in the German In-Depth Accident Study (GIDAS) (n = 214) - provide a detailed description of the respective accident and its consequences.
The group of pedelec riders proves to be predominantly an older but active user group that uses the pedelec often and for different purposes. Their predominantly high sense of safety in road traffic goes hand in hand with a rather low willingness to take risks. In the past two years, however, younger riders between the ages of 18 and 44 in particular have discovered the pedelec for themselves, who currently (still) make up a small proportion of both the user group and the accident figures. Collisions with a car and single-vehicle accidents, which are rarely recorded by the police, are the main causes of accidents. Even though most riders claim to be traveling faster on a pedelec than on a conventional bicycle, only a few accidents occur at speeds close to the maximum of 25 km/h pedal assistance that can be achieved by legal means. They often occur when standing or starting off and thus reflect the balance problems reported by many riders at low speeds. Selection effects are at work in both accident analyses, which limits the generalizability of the results. For example, GIDAS only includes accidents recorded by the police and therefore predominantly accidents with one other person involved, while older pedelec riders undergoing inpatient treatment are overrepresented in the
clinic survey. No reliable statements can be made about the users of S-pedelec riders and their accident history due to the low number of cases.
Based on the findings obtained, various recommendations for improving road safety for pedelec riders are derived which, in accordance with the focus of this study, are primarily aimed at the rider (e.g. increasing the helmet wearing rate) or their vehicle (e.g. technical support to improve riding stability even at low speeds). In addition, further studies are needed to describe pedelec accidents and their causes, also with a focus on car drivers as the most frequent parties involved in pedelec accidents with at least two riders, as well as a review and improvement of the quality of official statistics regarding the recognition of electrified bikes and their correct classification as pedelecs or S-pedelecs.
2016
ESAR Conference Hannover 2016
7th ESAR, "Expert Symposium on Accident Research" Proceedings 2016
ESAR Conference Hannover 2016
7th ESAR, "Expert Symposium on Accident Research" Proceedings 2016
ESAR Conference Hannover 2016
7th ESAR, "Expert Symposium on Accident Research" Proceedings 2016
2015
ESV Conference, Gothenburg, June 2015
2014
ESAR Conference Hannover June 2014
6th ESAR, "Expert Symposium on Accident Research" Proceedings 2014
IMSC International Motorcycle Safety Conference Orlando USA, November 2014
SAE paper 14B-0025/2014-01-0517, Detroit USA 2014
Evaluations from GIDAS
Accidents from 2005 to 2013
Presentation GUVU Ges. Unf.Ursachenforschung Cologne, May 2014
Accident Analysis and Prevention 65 (2014) 97-104
VKU Traffic Accident and Vehicle Technology
52nd volume / ISSN 0724-2050, 02/2014
ESAR Conference Hannover June 2014
International Conference Crashworthiness ICRASH, Malaysia, August 2014
International IFZ Conference Cologne, October 2014