| 41. |
- Fahrenkrog, Felix, et al.
(författare)
-
Impact Assessment of Developed Applications – Overall interactIVe Assessment
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- interactIVe introduces active intervention safety systems in order to increase traffic safety. The interactIVe functions are – depending on their purpose – able to brake and steer autonomously. Furthermore, the driver is continuously supported by interactIVe assistance systems which warn the driver in potentially dangerous situations. Seven demonstrator vehicles – six passenger cars of different vehicle classes and one truck - are built up in interactIVe to develop, test, and evaluate the next generation of safety systems. The three vertical subprojects in interactIVe SECONDS, INCA and EMIC have developed 11 different functions with a wide range of target areas. The developed advanced driver assistance systems (ADAS) comprise the following systems: • SP4 “SECONDS” dealing with functions, which support the driver continuously in the driving process. These functions should not only support the driver in dangerous situations, but help the driver to avoid them. • SP5 “INCA” dealing with functions, which combine longitudinal and lateral control of the vehicle in order to prevent imminent accidents. The INCA functions’ focus is not only on the collision avoidance in rear-end conflicts, but also on other types of conflicts, such as blind-spot and road departure situations. • SP6 “EMIC” deals with critical pre-crash applications, where collision mitigation can be realised at a reasonable cost. In order to evaluate the ADAS developed, an evaluation framework is required. Therefore, the subproject “Evaluation and Legal Aspects” is part of the interactIVe project, which has as main objective to provide this framework and to support the vertical subprojects in their evaluation work. The evaluation of the interactIVe functions has been divided into three main categories: • Technical Assessment to evaluate the performance of the developed functions and collect information and data for safety impact assessment. • User-Related Assessment to assess the functions from the user perspective, and also to provide further input to the safety impact assessment. • Impact Assessment to estimate how and how much the functions influence traffic safety. In this deliverable, the results of the evaluation in interactIVe are presented.
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| 42. |
- Gietelink, Olaf, et al.
(författare)
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Pilot Plan Design
- 2006
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This document describes the methodology for the evaluation and the assessment of the Safe Speed – Safe Distance (SSSD) concept of the SASPENCE system. It describes the evaluation using the prototype vehicles from a technical and functional point of view, as well as to assess such a system by a subjective rating by the driver. In particular, the first part is the report on the pilot plan design, that is the methodology of technical and functional evaluation, including the field-tests driver’s evaluation – the subjective evaluation with ordinary users on real road scenarios – performed on the SSSD system. The methodology for the technical and functional evaluation involves simulations using a computer environment, as well as experiments in the Vehicle Hardware-in-the-Loop (VEHIL) laboratory, and on-road test drives. The test method for traffic impact assessment (in terms of improved quality of the driving experience and traffic safety) will be focused on traffic simulation. The test case consists of an integrated set of methods and tools which will allow also a more rapid evaluation and assessment of future Advanced Driver Assistance Systems (ADASs).
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| 43. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Preliminary results from A Large Scale Trial with Intelligent Speed Adaptation in Lund, Sweden.
- 2001
-
Ingår i: [Host publication title missing].
-
Konferensbidrag (refereegranskat)abstract
- Within the framework of the Swedish national trial with Intelligent Speed Adaptation (ISA) in urban areas, 225 cars are equipped with an active gas pedal for a period of 10 months in the city of Lund. In order to evaluate the systems a number of studies are being carried out. The driving data of all equipped vehicles is logged with regard to time and speed, both before and after activating the system. Driver behaviour and workload is studied with the help of an instrumented vehicle. Possible system effects, such as speeds, interactions with other road-users and driving against red are studied in the field. Possible changes in driver attitudes and acceptance are studied by interviews.
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| 44. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Speed regulation by in-car active accelerator pedal – Effects on driver behaviour
- 2004
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Ingår i: Transportation Research. Part F: Traffic Psychology and Behaviour. - : Elsevier BV. - 1369-8478. ; 7:2, s. 77-94
-
Tidskriftsartikel (refereegranskat)abstract
- The long term effects of driving with an active accelerator pedal (AAP) on driver behaviour was studied by using an in car observation method. The AAP produced a counterforce in the accelerator pedal when the speed limit was reached, it could however be overridden by pressing the accelerator pedal harder. Twenty-eight drivers were studied when driving without the AAP and then when driving with the AAP after they had used the system in their own cars for at least six months. The results showed that the behaviour towards other road users improved, they had a correct yielding behaviour to a higher degree and were more likely to give pedestrians the right of way at zebra crossings when driving with the AAP. It was also found that the headway to the vehicle in front increased slightly with the system. There were also signs of negative behavioural modifications in the form of drivers forgetting to adapt their speed to the speed limit or the prevailing traffic situation when they were not supported by the AAP. These effects, however, were statistically not significant.
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| 45. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Speed Regulation by in-car active Accelerator pedal – effects on speed and speed distribution
- 2002
-
Ingår i: IATSS Research. - 0386-1112. ; , s. 60-66
-
Tidskriftsartikel (refereegranskat)abstract
- The effects on speeds and speed distribution were studied in a large scale field trial with an in car system for speed adaptation in the city of Lund, Sweden. In the trial 290 vehicles were equipped with an "active accelerator pedal" and data logger for a period of 3-11 months. Data was logged in each test vehicle during the whole trial and was analyzed for 3 one-month periods: Before activating the system, after short time use and after long time use. The results showed significant reductions in the speed level. Speeds on stretches decreased statistically significantly (p<0.05) at 60 out of 69 observed sections. The effects were largest on arterial roads, at mid-block sections, where the prevailing traffic conditions and street design allows higher speeds. The standard deviation decreased on all arterial roads, mainly due to the decrease in speed of the fastest vehicles but there is also an effect from an increase in speed of the slowest vehicles. On streets with mixed traffic no differences in speed or speed distribution could be shown. This is most likely due to the fact that speeds were already controlled by the prevailing traffic conditions and they already were so low that the system never had to interfere. Further research is needed in order to investigate possible behavioral adaptation effects when the system is active as well as inactive and how driver behavior would be influenced in a situation where a large part of the vehicle fleet equipped with an active accelerator pedal.
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| 46. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Validation of in-car observations, a method for driver assessment
- 2004
-
Ingår i: Transportation Research. Part A: Policy & Practice. - : Elsevier BV. - 0965-8564. ; 38:2, s. 127-142
-
Tidskriftsartikel (refereegranskat)abstract
- An in-car observation method with human observers in the car was studied to establish whether observers could be trained to observe safety variables and register driver's behaviour in a correct and coherent way, and whether the drivers drove in their normal driving style, despite the presence of the observers. The study further discussed the observed variables from a safety perspective. First three observers were trained in the observation method and on-road observations were carried out. Their observations were then compared with a key representing a correct observation. After practising the observation method the observers showed a high correlation with the key. To establish whether the test drivers drove in a normal way during the in-car observations, comparisons of 238 spot-speed measurements were carried out. Driver's speeds when driving their own private cars were compared with their speeds during the in-car observations. The analysis showed that the drivers drove in the same way when being observed as they did normally. Most of the variables studied in the in-car observations had a well documented relevance to traffic safety. Overall, in-car observation was shown to be a reliable and valid method to observe driver behaviour, and observed changes provide relevant data on traffic safety. (C) 2003 Elsevier Ltd. All rights reserved.
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| 47. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Validation of Wiener Fahrprobe – A method description.
- 2000
-
Konferensbidrag (refereegranskat)abstract
- On the decision of the Swedish government, the Swedish National Road Administration (SNRA) has started a large-scale trial with Intelligent Speed Adaptation (ISA) in urban areas. One of the four test sites is the city of Lund. At the Department of Technology and Society, Lund University, research about ISA has been carried out since 1986 and the first field study was carried out in 1993. The ongoing large scale trial is based on experience from previous research on the concept of ISA. It is likely to assume that ISA will change the speed behaviour for the test drivers, but it is also likely that there will be secondary effects related to driver behaviour. Examples of such effects are a change in communication with other road users, improved car following behaviour or, on the negative side, compensatory or automated behaviour. In order to assess the driver behaviour in the Lund trial, a method called Wiener Fahrprobe (WF) will be used. The method was originally developed by Risser and Brandstätter (1985) as an instrument to analyse driving behaviour in order to make sure whether a person is apt for driving a car or not. In the WF two observers ride along with the test-subject, one of them is doing standardised observations and the other is doing free observations (non-predictable events). In addition to the observers, an instrumented vehicle will be used to obtain continuos variables such as speed, speed-limit, distance to the vehicle in front etc. When doing observations with observers on the spot there is always a scepsis that the test-subjects will be affected and behave in a way that does not correspond with their normal driving. There are a few studies that has dealt with this issue and there are some differences in the results. Höffner, K.J. (1978) found that the behaviour of moped riders did not change when they knew that they where observed. On the other hand, Rathmayer, Beilinson, Kallio, Raitio (1999) found that subjects driving in an instrumented car with and without the presence of an experiment leader had a lowered mean speed by 1-2 km/h when the experiment leader was present. They further found that acceleration and deceleration was smoothed down and lateral acceleration was reduced. In Lund, all the test vehicles will be equipped with data-logs saving data about among others time, position and speed. These data are collected for two months before the installation of ISA and for 2*two months after the installation. These data will be compared with the data gathered during the test-drive and the differences, if any, will be analysed. The analysis will then show how and of which magnitude the drivers are affected by the observer.
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| 48. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Will ISA be effective? Analysis of the active accelerator pedal’s effect on different driver groups
- 2004
-
Konferensbidrag (refereegranskat)abstract
- The effects of the Active Accelerator Pedal (AAP), on speed behaviour of drivers with different backgrounds and attitudes was analysed. It was found that most of the drivers initially reduced their speed to the speed limit. However, after driving with the system for a while, speeds increased. Drivers who had a high speed without the AAP started to speed again. This finding suggests that an advisory system, such as the tested AAP, is efficient in reducing the speed of drivers who are speeding inadvertently, but it is not as efficient, however, in reducing the speed of drivers who speed deliberately.
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| 49. |
- Hjälmdahl, Magnus, et al.
(författare)
-
Workload-study of ISA-drivers - A method description.
- 2000
-
Konferensbidrag (refereegranskat)abstract
- On the decision of the Swedish government, the Swedish National Road Administration (SNRA) has started a large-scale trial with Intelligent Speed Adaptation (ISA) in urban areas. One of the four test sites is the city of Lund. At the Department of Technology and Society, Lund University, research about ISA has been carried out since 1986 and the first field study was carried out in 1993. The ongoing large scale trial is based on experience from previous research on the concept of ISA. One hypothesis regarding the effects of ISA is that the drivers will drive slower and in a more relaxed way, thus reducing the workload induced by the driving task. In order to test this hypothesis, 25 test-subjects will drive an instrumented vehicle on a predetermined route. The route consists of both urban and rural environment of varying complexity. In total, the test-drives will be carried out three times, before using ISA, after using it for a short period and finally after one year driving with ISA. During the test-drive the drivers will carry out a secondary task called “peripheral dot detection”. The task consists of responding to two lights, one on each side of the driver, by pressing one of two buttons, one for each light. The lights will be lit for 0.75 seconds and the response time, missed responses and left / right errors will be registered. In addition to the secondary task a number of other indicators of workload will be used such as lane position, speed, steering wheel rotation and NASA-TLX. Stress induced by other road-users will also be studied by studying changes in rear-view mirror glance-frequency with and without vehicles behind.
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| 50. |
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