# Towards Understanding Driver Acceptance of C-ITS Services--A Multi-Use Case Field Study Approach
## 5 Conclusions  
During the last 15 years, C-ITS services have been extensively specified, deployed, and tested, culminating in their initial commercial applications and rollouts. Starting from research projects and in the late 2000s, finally, commercial deployments are available in interurban and urban areas. With the increasing maturity, it became more and more important to understand the specific impacts of C-ITS and how users accept the provided services. In two field studies, ESRIUM and ASFINAG studied the user acceptance of four different C-ITS services were evaluated following the approach of the Technology Acceptance Model. Evaluation included a mixed-method approach to gain both insights during real-life driving situations and further insights from an online questionnaire. In total, 10 truck drivers and 8 car drivers experienced the C-ITS service in real life in the vehicle. 27 and 68 people, respectively, took part in the ESRIUM and ASFINAG study online questionnaire. In the following, the main results are summarized based on the research questions (ref. Section 1.6). 1. _Perceived level of usefulness_: In both field studies, around 60% of respondents reported concerns about poor road surface conditions or potential driving hazards. In the ESRIUM study, 85% of participants expressed interest in receiving such information through in-vehicle systems. Similarly, in the ASFINAG study, 50% of online respondents and between 75% and 87.5% of interview participants agreed that in-vehicle C-ITS information is helpful. Trust in these systems increases when the information comes from road operators; roughly 90% of ESRIUM participants and all ASFINAG test drivers reported trusting operator-provided data. Furthermore, most participants (92% in ESRIUM and 78% in ASFINAG) believed that road safety is significantly improved by this information. Both studies also found that drivers paid close attention to in-vehicle alerts, with minimal distraction, regardless of age, gender, or driving experience. 2. _Perceived ease of use_: In the ESRIUM project, all 10 truck drivers strongly agreed that the bad surface information provided during their test drive was clear and easy to understand. Likewise, in the ASFINAG study, every car driver reported that the C-ITS services were straightforward and intuitive, underscoring the system's strong ease of use. 3. _Behavioral intention to use_: Between 90% and 93% of respondents in both field studies expressed a desire to receive in-vehicle warnings about current traffic jams. The second most valued information type, with approval rates between 75% and 86%, was warnings about specific situations such as bad weather, roadworks, or approaching emergency vehicles. Regulatory speed limit information ranked third, considered important by 75% to 82% of participants. The newly introduced ESRIUM use case--notifications about poor road surface quality like potholes or ruts--was relevant for about 50% of respondents. Participants were most likely to follow \"reduce speed\" or \"change lane\" instructions when the alerts were clearly linked to safety. However, willingness to pay remained low among online respondents--only 18% in the ASFINAG study and just three drivers in the ESRIUM project. In contrast, those who experienced the services firsthand during test drives were more receptive, with 50% to 75% indicating a willingness to pay, depending on the specific service. Among these, preferred payment models included either a monthly fee or a pay-per-use system, typically ranging from 5 to 10 euros per month. 4. _Alignment and support by existing C-ITS literature_: In general, IVIS and C-ITS play a vital role in improving road safety and ensuring compliance with traffic regulations by delivering real-time updates and enhancing situational awareness [33; 42]. IVIS warnings, in particular, have been shown to significantly improve drivers' awareness of road conditions [35].