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Bergisch Gladbach, Germany

Will S.,Robert Bosch GmbH | Schmidt E.A.,Federal Highway Research Institute BASt
IET Intelligent Transport Systems | Year: 2015

A riding simulator study (n = 14) was conducted in order to test the sensitivity of performance measures, subjective ratings as well as physiological measures in controlled variations of rider workload. In a second study (n = 15), these parameters were used in order to assess the effects of different secondary tasks. The task of operating an on-bike information system led to the highest workload, for example, indicated by deteriorated lane keeping and higher subjective ratings compared with a simple visual, an auditory and no secondary task at all. The third study (n = 18) focused on the effects of eyes-off road while riding using the method of occlusion. This revealed that the participants felt safe to black out the scenery quite often and long. Periods of occlusion were related to a higher mean velocity and a tendency to ride more on the left side of the lane compared with riding with enabled projection. © The Institution of Engineering and Technology 2015. Source

Gelau C.,Federal Highway Research Institute BASt | Sirek J.,University of Regensburg | Dahmen-Zimmer K.,University of Regensburg
Transportation Research Part F: Traffic Psychology and Behaviour | Year: 2011

In countries with right lane traffic left-turn manoeuvres at intersections are known to be particularly critical for elderly drivers. It has been suggested that the implementation and use of Advanced Driver Assistance Systems (ADAS) might offer a solution to compensate for age-related weaknesses in driving-related skills. In the present paper an experiment is reported which explored the effects of time pressure on the performance of left-turn manoeuvres supported by an ADAS function ('time gap assistant'). The study was performed in a fixed-base driving simulator with 20 younger (22-37) and 21 elderly drivers (60-84) who were observed when negotiating left-turn manoeuvres on rural roads with and without the assistance function active. Subjects performed the task once under conditions of time pressure once without. Results indicate that both age groups used the assistance function to perform the left-turn manoeuvres with shorter time gaps. Under conditions of time pressure this effect was more pronounced, and the effects of time pressure were stronger for the elderly. However, there were only weak indications for a specific benefit of the assistance function for the elderly. © 2010 Elsevier Ltd. All rights reserved. Source

Vetters A.,Sudan University of Science and Technology | Jaehrig T.,Federal Highway Research Institute BASt
6th IEEE Conference on Cognitive Infocommunications, CogInfoCom 2015 - Proceedings | Year: 2015

In 2012, new rural road design guidelines (RAL) has been released in Germany. They define different types of roads including different principles for passing. On new roads with a high road function level, passing is safeguarded by passing lanes. However, passing lanes cannot be recommended as a standard on each road type. For roads with a lower road function level and on most of the existing rural road network, passing is permitted by using the oncoming traffic lane. The passing sight distance used today is based on a geometrical model which has been the subject of an empirical research in 1986. Because of the change in the vehicle fleet the passing sight distance model needs to be verified and updated. For this purpose, passing maneuvers are recorded by using a drone. The methodology allows capturing the entire passing maneuver including the approach of the opposing traffic. Thereby, the road geometry as well as traffic parameters (average annual daily traffic - AADT, heavy good vehicles - HGV) are considered. Overall, more than 1.100 passing maneuvers have been captured and analyzed. As a research result, recommendations for the required passing sight distance on single two lane rural roads will be given. © 2015 IEEE. Source

Tzanakos K.,Technical University of Crete | Mimilidou A.,Technical University of Crete | Anastasiadou K.,Federal Highway Research Institute BASt | Stratakis A.,Technical University of Crete | Gidarakos E.,Technical University of Crete
Waste Management | Year: 2014

In the present work, bottom and fly ash, generated from incinerated medical waste, was used as a raw material for the production of geopolymers. The stabilization (S/S) process studied in this paper has been evaluated by means of the leaching and mechanical properties of the S/S solids obtained. Hospital waste ash, sodium hydroxide, sodium silicate solution and metakaolin were mixed. Geopolymers were cured at 50. °C for 24. h. After a certain aging time of 7 and 28. days, the strength of the geopolymer specimens, the leachability of heavy metals and the mineralogical phase of the produced geopolymers were studied. The effects of the additions of fly ash and calcium compounds were also investigated. The results showed that hospital waste ash can be utilized as source material for the production of geopolymers. The addition of fly ash and calcium compounds considerably improves the strength of the geopolymer specimens (2-8. MPa). Finally, the solidified matrices indicated that geopolymerization process is able to reduce the amount of the heavy metals found in the leachate of the hospital waste ash. © 2014 Elsevier Ltd. Source

Huth V.,University of Lyon | Gelau C.,Federal Highway Research Institute BASt
Accident Analysis and Prevention | Year: 2013

The strong prevalence of human error as a crash causation factor in motorcycle accidents calls for countermeasures that help tackling this issue. Advanced rider assistance systems pursue this goal, providing the riders with support and thus contributing to the prevention of crashes. However, the systems can only enhance riding safety if the riders use them. For this reason, acceptance is a decisive aspect to be considered in the development process of such systems. In order to be able to improve behavioural acceptance, the factors that influence the intention to use the system need to be identified. This paper examines the particularities of motorcycle riding and the characteristics of this user group that should be considered when predicting the acceptance of advanced rider assistance systems. Founded on theories predicting behavioural intention, the acceptance of technologies and the acceptance of driver support systems, a model on the acceptance of advanced rider assistance systems is proposed, including the perceived safety when riding without support, the interface design and the social norm as determinants of the usage intention. Since actual usage cannot be measured in the development stage of the systems, the willingness to have the system installed on the own motorcycle and the willingness to pay for the system are analyzed, constituting relevant conditions that allow for actual usage at a later stage. Its validation with the results from user tests on four advanced rider assistance systems allows confirming the social norm and the interface design as powerful predictors of the acceptance of ARAS, while the extent of perceived safety when riding without support did not have any predictive value in the present study. © 2012 Elsevier Ltd. Source

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