[ADAS and automation-a relevant contribution to maintaining mobility of older drivers?] / Fahrerassistenzsysteme und automatisiertes Fahren ­ ein relevanter Beitrag zum Erhalt der Mobilität im Alter?

Driving is the most important and safest form of mobility for the majority of senior citizens. However, physical and mental performance gradually decline with age, which can lead to more problems, critical situations or even accidents. Vehicle technology innovations such as advanced driver assistance systems (ADAS) have the potential to increase the road safety of older people and maintain their individual mobility for as long as possible.This overview article aims to identify ADAS that have the greatest potential to reduce the number of accidents involving older drivers. For this purpose, the accident and damage occurrence as well as the driving behaviour and compensation strategies of older people are examined in more detail. Suitable ADAS should compensate for typical driver errors, reduce information deficiencies and have a high level of acceptance. For older drivers, emergency braking, parking assistance, navigation, intersection assistance and distance speed control systems as well as systems for detecting blind spots and obstacles appear to be particularly suitable.Some of the disadvantages of ADAS are the lack of market penetration, acceptance problems and interface designs that have not yet been optimally adapted to the needs of older users. For older drivers in particular, it appears to be a priority to develop coherent and integrated solutions in the sense of cooperative assistance instead of pushing ahead with high and full automation with many system limits and exceptions, which can place high demands on attention, for example if the vehicle has to be taken over in a critical situation.

Visual advisory warnings about hidden dangers: Effects of specific symbols and spatial referencing on necessary and unnecessary warnings.

Augmented reality has the potential to improve the effectiveness of collision warnings in vehicles because they inherently convey spatial information about the hazard and can guide the attention of the driver towards it. For future warning systems, which can detect sight obstructed dangers, related work already revealed some advantages. In a driving simulator study with 80 participants, we investigated the effects of three corresponding design parameters which are commonly integrated at augmented reality warnings. This study analyzes the individual contribution of specific warning symbols, warning animation, and spatial referencing. Part one of the study concentrates on the effectiveness of necessary warnings and part two on the drivers' compliance despite false alarms. Compared to the control condition with static unspecific warning symbols, static specific warning symbols depicting the type and motion direction of the hazard led to several but inconsistent advantages. The scaling animation only improved subjective evaluation. However, spatial referencing of an (unspecific) warning symbol consistently improved drivers' reactions to as well as evaluations of necessary and unnecessary warnings. The results emphasize the potential of spatial referencing, particularly for in-vehicle warnings of future collision avoidance systems.

Augmented reality warnings in vehicles: Effects of modality and specificity on effectiveness.

In the future, vehicles will be able to warn drivers of hidden dangers before they are visible. Specific warning information about these hazards could improve drivers' reactions and the warning effectiveness, but could also impair them, for example, by additional cognitive-processing costs. In a driving simulator study with 88 participants, we investigated the effects of modality (auditory vs. visual) and specificity (low vs. high) on warning effectiveness. For the specific warnings, we used augmented reality as an advanced technology to display the additional auditory or visual warning information. Part one of the study concentrates on the effectiveness of necessary warnings and part two on the drivers' compliance despite false alarms. For the first warning scenario, we found several positive main effects of specificity. However, subsequent effects of specificity were moderated by the modality of the warnings. The specific visual warnings were observed to have advantages over the three other warning designs concerning gaze and braking reaction times, passing speeds and collision rates. Besides the true alarms, braking reaction times as well as subjective evaluation after these warnings were still improved despite false alarms. The specific auditory warnings were revealed to have only a few advantages, but also several disadvantages. The results further indicate that the exact coding of additional information, beyond its mere amount and modality, plays an important role. Moreover, the observed advantages of the specific visual warnings highlight the potential benefit of augmented reality coding to improve future collision warnings.

Reliability of drivers in urban intersections.

The concept of human reliability has been widely used in industrial settings by human factors experts to optimise the person-task fit. Reliability is estimated by the probability that a task will successfully be completed by personnel in a given stage of system operation. Human Reliability Analysis (HRA) is a technique used to calculate human error probabilities as the ratio of errors committed to the number of opportunities for that error. To transfer this notion to the measurement of car driver reliability the following components are necessary: a taxonomy of driving tasks, a definition of correct behaviour in each of these tasks, a list of errors as deviations from the correct actions and an adequate observation method to register errors and opportunities for these errors. Use of the SAFE-task analysis procedure recently made it possible to derive driver errors directly from the normative analysis of behavioural requirements. Driver reliability estimates could be used to compare groups of tasks (e.g. different types of intersections with their respective regulations) as well as groups of drivers' or individual drivers' aptitudes. This approach was tested in a field study with 62 drivers of different age groups. The subjects drove an instrumented car and had to complete an urban test route, the main features of which were 18 intersections representing six different driving tasks. The subjects were accompanied by two trained observers who recorded driver errors using standardized observation sheets. Results indicate that error indices often vary between both the age group of drivers and the type of driving task. The highest error indices occurred in the non-signalised intersection tasks and the roundabout, which exactly equals the corresponding ratings of task complexity from the SAFE analysis. A comparison of age groups clearly shows the disadvantage of older drivers, whose error indices in nearly all tasks are significantly higher than those of the other groups. The vast majority of these errors could be explained by high task load in the intersections, as they represent difficult tasks. The discussion shows how reliability estimates can be used in a constructive way to propose changes in car design, intersection layout and regulation as well as driver training.