User related assessment of Continuous Support & Curve Speed Control (FFA)

• The aim of the user related assessment was to study perceived advantages, disadvantages, usefulness, trust, acceptance, willingness to have and pay for the driver assistance system: Continuous Support & Curve Speed Control developed by FFA within the framework of the SECONDS subproject. Due to restrictions in driving in real traffic, assessment activities were limited to driving on a test track by naïve test drivers to be demonstrated the system. Nineteen persons took part in two focus groups, ten males and nine females. At the end of the focus group discussions the participants were asked to individually fill in a short questionnaire with specific questions about the system. The participants think that the system helps the driver in situations where he/she is distracted or inattentive. Situations, like lane-departure, blind-spot and rear-end conflicts are stated as accident situations the system would help to avoid. The fact that the system recognises dangerous situations earlier than the driver is seen as an advantage. It was stated that the system can do things, a normal human being is not able to do and it also reacts faster than the driver. The system would enhance driver comfort and it also would educate drivers to use the indicator. As disadvantages and concerns were taken up that the driver might react wrongly on the warnings by the system, due to impulsive steering in the opposite direction when the steering wheel gives the impulse away from the danger. Some concerns were that drivers would rely too much on the system, they would drive more relaxed and not with full attention of what is going on around them and it might be a problem when the system does not work. If the system gives too many warnings or stimuli, the driver might get confused. After some time, if the warnings come too often one would not pay any attention anymore. It was discussed if one really wants to be warned in all situations and that the system might get on ones nerves if one is corrected all the time. When one changes between cars with and without the system, one might expect to get a warning which will not come. The possible costs of the system and how they would be distributed were seen as problematic. When the costs are too high in relation to the total costs of the car, it would be a problem. Possible compulsoriness in all cars might be made by law or by subvention by the state or insurance companies should offer advantages when such a system is implemented in the car. It was stated that the system has to work completely correctly all the time and it has to inform the driver if it does not work. When one trusts the system, one would use it all the time but the trust will be built with time. The participants would fully trust the system as they believe that car manufacturers have tested it and erased all mistakes. They thought that the system would only be sold if it was 100% reliable. The system would be more useful on motorways or on roads with higher speed limits due to the fact that one would have less time to react there in a dangerous situation. More severe accidents occur there and therefore it would have a better effect there. On urban roads during rush hours there might be too many warnings by the system. However, it would have advantages in urban areas where the rear-end and the blind-spot warning would be helpful, as well as in situations when a car overtakes unexpectedly or a cyclist comes from behind and passes on the right side. The system was seen useful especially when driving in the night when drivers get tired quicker and more inattentive. Some participants believed that they would use the system all the time as they would be afraid to forget to turn the system on again. A possible situation when the system would be turned off is the use a rented car for only a short time period. Also, bad weather conditions, like heavy rain, were mentioned in this respect and that one would not trust the system that it would work correctly and therefore would not use it. The system would be more useful for older drivers as it would compensate for physical handicaps e.g. when one cannot move his/her head so easily. On the other hand, due to the higher accident risk of younger drivers, it would be more useful for them. The different types of warnings were seen as positive. The vibration of the steering wheel can be very effective and it has the potential to get the attention of the driver. Non-visual warning signals are very good, as one has his eyes on the road and it would cost too much time to check the display to see what to do. The visual warning does not do any harm as one can ignore it anyway. Some concerns regarding the haptic signals were mentioned. The participants were not sure how they would react when the steering wheel starts moving on its own. Some thought that, especially for the first time, they would be distracted or would react intuitively and try to steer in the other direction. The system should not warn the driver too often. When there are too many, especially acoustic warnings then it might disturb or get on ones nerves. If this would be the case, one would turn off the system. The participants had different opinions regarding if the system should only warn and give recommendations how to react or if it should automatically act by steering or braking. A combination of modalities was discussed and that the system should warn the driver as long as possible but if an appropriate reaction of the driver does not come then it should automatically take over. It was stated that it would be good to get an introduction by the car seller about how the system works. The introduction would especially be needed for older drivers as they are not so familiar with new technologies. Also, the possibility that novice drivers can get information in driving schools was discussed. Nevertheless, the system should be self-explaining, because one does not always has the opportunity to get an introduction to it or can test it during a test ride. It was stated that the handbook is not needed at all because it is only for specific questions, on the other hand it was also mentioned that there are people who read the handbook and therefore it is needed anyway. A suggestion was made to implement a demo-mode so that the warnings can be shown while the car stands still. This would especially have the advantage to see how the haptic signals work. Some participants criticised the fact that different car manufacturers develop different systems but with the same aim. Some of the systems brake automatically while others give warnings or use different acoustic signals. It is important that all manufacturers develop one system because in the end the many different systems are a problem for the customers as they have to adapt every time they change to another car. Some recommendations were made regarding the different types of warnings: all situations should be treated equally and therefore the acoustic warning should come in all situations. Furthermore, the situations could be divided due to their potential danger. The system should only give a gentle sound in the beginning when the situation is not critical, but as soon as it becomes unsafe, there should be a loud signal. Other stimuli, like the phone or radio should be turned off when the warning comes so that it is sure that the driver receives the warning. Some participants would appreciate if different parts of the system could be turned off and they could choose to use the systems which they want to use. Only one display should be used so one does not have to move eyes between the navigation display and the display of the warning system. While almost all participants had the opinion that the system would decrease the risk to be involved in an accident on motorways and rural roads „only“ two third agreed (totally) that the system would decrease the accident risk on urban roads. The participants thought comfort would mostly be enhanced on motorways followed by rural roads and urban roads. The disagreement with the statement was highest for urban roads. Some participants were undecided if the system would enhance their comfort on rural roads and motorways or even disagreed with the statement for this type of roads. More than three-fourth thought that they would use the system almost all the time on motorways. Almost two-thirds thought they would use it between 80 and 100% of the time on rural roads while “only” one third thought they would use it almost all the time in urban areas. Fifteen participants (more than three-fourth) would be willing to pay more than 500 Euros to implement the system in their car. Six participants would pay between 750 and 1.000 Euros and one participant would pay even more than 1.000 Euros. Three participants stated that they would pay between 250 and 500 Euros and one participant stated that he/she would not be willing to spend more than 250 Euros on the system. Eighteen participants stated that they would recommend the system to a friend.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Infrastrukturteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Infrastructure Engineering (hsv//eng)

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