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.
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.
Bartolomaeus W.,Federal Highway Research Institute BASt
ICSV 2016 - 23rd International Congress on Sound and Vibration: From Ancient to Modern Acoustics | Year: 2016
Spectral data of vehicle emission are available from single pass-by measurements according to the Statistical Pass-by Method, SPB, for all surface types used in Germany. These data can be used as input data for a method to convert emission data into the format of annex F-4 of CNOSSOS-EU. In a first step these input data has to smooth out. Therefore a linear regression analysis for all single pass-by levels with speed will be performed. The CNOSSOS-EU emission model is limited to frequencies from 63 Hz to 8 kHz but our spectral data cover a range from 20 Hz to 20 kHz. There are several methods to solve this problem. The emission model of CNOSSOS-EU has two parts of sound energy, the rolling noise part and the propulsion noise part. But from SPB-measurements we obtain both parts together. For dens non absorbing road surfaces there are nine free parameters for fitting the data into the rolling noise part of the CNOSSOS-EU emission model: one parameter for the overall level and eight parameters for the slope in each of the octave bands used in CNOSSOS-EU. For absorbing surfaces eight of the parameters are also used for the spectral absorption coefficients in the propulsion noise model. The idea is to make use of a multidimensional fitting procedure for all parameters to obtain the best possible approximation to the emission curve for the given surface typ. The method will be explained in detail. So it can be used whenever SPB-data are available. The parameters for two German surface types will be presented.
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.
Schulze H.,Federal Highway Research Institute BASt |
Kossmann I.,Federal Highway Research Institute BASt
Safety Science | Year: 2010
Mobility is a matter of great importance in daily life: However, it also causes costs and involves accident risks. To make mobility safer and reduce accident risks, a scientifically based road safety management is needed. Within such a safety management system, a concert of adequate and efficient strategies, tools and measures is developed and implemented. To ensure that the chosen means are efficient they should be derived from research evidence. Secondly, research is also needed to regularly monitor the impact of road safety management tools, serving as a " controlling instrument" for the appropriateness of safety management efforts. This article explains the main strategic aspects of safety management in Germany and illustrates it exemplarily on the basis of two recently implemented road safety measures. © 2010 Elsevier Ltd.
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.
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.
Holst R.,Federal Highway Research Institute BASt
Life-Cycle and Sustainability of Civil Infrastructure Systems - Proceedings of the 3rd International Symposium on Life-Cycle Civil Engineering, IALCCE 2012 | Year: 2012
The German BMS is designed to optimize both at the network level, as well as at the object level. The network layer will mainly be used for budget planning. The object level allows the calculation and presentation of different maintenance strategies and their impact on direct and indirect costs. In the BMS bridges, which show damages, are considered for optimization. The implemented algorithms allow considering a bridge from the beginning of its life time. Using these algorithms and deposited catalogues it's possible to calculate for different strategies life cycle considerations also for decades. Thus the road authorities' get a basis for decisions for the choice of preservation strategy and where the bridge was not built for the planning and erection phase of the bridge.
Holst R.,Federal Highway Research Institute BASt
Bridge Maintenance, Safety, Management, Resilience and Sustainability - Proceedings of the Sixth International Conference on Bridge Maintenance, Safety and Management | Year: 2012
For the area of federal highways in Germany a bridge-management-system (BMS) is developed. Since July 2011, the program modules are available for internal testing applications. This BMS-system is based on object-related data from the program "SIB-Bauwerke". This paper presents the BMS and initial results. © 2012 Taylor & Francis Group.
Aljazzar T.,Federal Highway Research Institute BASt |
Al-Qinna M.,Hashemite University
Environmental Science and Pollution Research | Year: 2016
This study aimed to better understand nitrate transport in the soil system in a part of the state of North Rhine-Westphalia, in Germany, and to aid in the development of groundwater protection plans. An advection-diffusion (AD) cell was used in a miscible displacement experiment setup to characterize nitrate transport in 12 different soil samples from the study area. The three nitrate sorption isotherms were tested to define the exact nitrate interaction with the soil matrix. Soils varied in their properties which in its turn explain the variations in nitrate transport rates. Soil texture and organic matter content showed to have the most important effect on nitrate recovery and retardation. The miscible displacement experiment indicated a decrease in retardation by increasing sand fraction, and an increase in retardation by increasing soil organic matter content. Soil samples with high sand fractions (up to 94 %) exhibited low nitrate sorption capacity of less than 10 %, while soils with high organic matter content showed higher sorption of about 30 %. Based on parameterization for nitrate transport equation, the pore water velocity for both sandy and loamy soils were significantly different (P < 0.001). Pore water velocity in sandy soil (about 4 × 10−3 m/s) was about 100 to 1000 larger than in loamy soils (8.7 × 10−5 m/s). On the other hand, the reduction in nitrate transport in soils associated with high organic matter was due to fine pore pathways clogged by fine organic colloids. It is expected that the existing micro-phobicity increased the nitrate recovery from 9 to 32 % resulting in maximum diffusion rates of about 3.5 × 10−5 m/s2 in sandy soils (sample number CS-04) and about 1.4 × 10−7 m/s2 in silt loam soils (sample number FS-02). © 2016 Springer-Verlag Berlin Heidelberg