Improving the safety and mobility of vulnerable road users through ITS applications [VRUITS] D4.1 Usability assessment of selected applications
reportposted on 10.02.2017, 09:54 by Pietro Carlo Cacciabue, Mirella Cassani, Daniel Bell, Andrew Morris, Graham Hancox, Alejandra Beatriz Garcia Melendez, Juan Plaza Vaquero, Maartje de Goede, Ellen Wilschut
n recent years ITS applications have assisted in reducing the number of road traffic accident fatalities in Europe. However, Vulnerable Road Users (VRUs) have not benefited to the same extent as vehicle users. The EU-sponsored VRUITS project assesses the safety and mobility impacts of ITS applica-tions for VRUs. This process involves assessing the impacts of current and upcoming ITS applications on the safety and mobility of VRUs, identifying how the usability and efficiency of ITS applications can be improved and recommending which actions have to be taken at a policy level to accelerate de-ployment of such ITS. This deliverable reports the work performed during the second period of activity focusing on a number of selected existing ITS which are already present on the market. In particular, user-acceptance and usability of existing ITS services for VRUs, have been assessed, focusing on comfort/mobility and ef-fectiveness of related information (the HMI) for special user groups, such as elderly subjects. In Chapter 1 the Project and the objectives of the deliverable are described. The concept of the Vul-nerable Road Users and ITS interfaces are then presented. In chapter 2 the method for evaluation and screening of existing ITS systems is described. The usabil-ity assessment has been performed by experts, which were provided a detailed description of several ITS systems for VRUs. Starting from the inventory of ITS systems in D2.1, the most suitable systems for usability assessment were selected. The selection of the ITS systems to be assessed has been conducted following the feedback received from the activity carried out in WP 2. A questionnaire has been developed for the evaluation of interfaces, based on the literature work already carried out in the past. The selected ITS systems have been studied in detail in order to develop sufficient material to distrib-ute to interviewees together with the questionnaire. This aimed to support the interface usability pro-cess even in situations where the actual systems were not available. The 4 selected systems are mainly dedicated to pedestrians, drivers of PTWs, cyclists and drivers, and are: Intelligent pedestrian traffic signal Cyclist digital rear-view mirror PTW oncoming vehicle information assistance system Blind spot detection system his process led to the development of a substantial amount of material and information (mainly in the form of links to video and on-line demonstrations of ITS) that were made available to interviewees to support their evaluation process. The complete set of material, i.e., the questionnaire and supporting material, for 4 different ITS have been distributed to a number of interviewees. In Chapter 3 the VRUITS questionnaire used for usability is presented and explained together with the data collection findings. Chapter 4 discusses the actual survey results about ITS usability. A total of 152 individual replies were collected, and each of the system was assessed by 35-42 persons. This data has been collected and analysed, utilising standard statistical tools, mainly SPSS (Statistical Package for the Social Sciences) for data mining and data analysis. Finally Chapter 5 and 6 a discussion about the results as well as the research conclusions are report-ed. The overall findings of the investigation revealed that it was possible to discriminate and identify areas of improvement for usability issues on all the four ITS systems under investigation. In general, the results revealed common usability patterns across the four ITS systems. In particular, the Perception of risk avoidance (given by the ITS system) and Communication of Risk (risk warning by the ITS) were rated the best usability properties of the various ITS systems. Providing feed-forward information about incoming hazardous situations and subsequent appropriate perception of risk avoid-ance are the best properties among all the four ITS systems. Also, the highest rated usability features across all ITS systems were the clarity of the system functions (Explicitness), the way the systems work and operate (Functionality) and the degree of control by the user (User Control). Some major areas of improvement were revealed also. Firstly, the lowest rated usability features across all four ITS systems were System Monitoring, Flexibility and Consistency. This latter finding could suggests the evidence that all four ITS systems might need more focus on adaptability to road context, consistency of functions in difficult weather conditions and finally a more active monitoring of human behaviour in response to the ITS (where this is applicable). Secondly, Trust in the ITS system, and the perception of Safety Improvement revealed to be weak ITS properties overall. Some work on trust in safety and ITS automation and safety improvement perception (in using such systems) could be brought forward as the aim of the ITS system for VRUs is exactly to increase Safety. In fact, a user attitude of trust in the systems and belief that such systems could improve their safety is a substantial desirable scenario to strive for. Notably, younger people (<38 years) tended to rate the general usability of the four systems slightly more positively than the older people (>62). Nevertheless the rating is on the same direction for both sub-samples of respondents. Finally, the replies from experts in the sample did not differ from the overall group for the general usability and the for usability scales except for minor differences.
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no 321586