User-related Assessment of the Traffic Jam Assist system of VCC

Forskningsoutput: Bok/rapportRapport


The aim of the user related assessment of the VCC demonstrator’s “Traffic Jam Assist” system was to study trust, usefulness, perceived advantages, disadvantages, acceptance, and willingness to pay for the driver assistance system. The system provides automated speed control and lane keeping. If a lead vehicle is present, the automated vehicle adapts its speed in order to maintain a pre-set time distance to the lead vehicle.
Due to restrictions of driving by naïve drivers in real traffic conditions, assessment activities were limited to driving on a test track by a number of test drivers (employees at Volvo Car Company with administrative duties) to be demonstrated of the system.
Fifteen persons took part in the study, 12 males and 3 females. After driving on the test track and experiencing the system in action, the participants filled in a questionnaire. Most participants thought that “the system was a competent performer” and they also had “confidence in the advice given by the system”. The majority expressed that they “can rely on the system to do its best every time”. Considering whether the driver can depend on the system the majority of the answers were on the “disagree” side and partly neutral, only one respondent agreed strongly that he/she can depend on the system. Considering the statement “I can rely on the system to behave in consistent ways”, most of the responses were in the middle, i.e. close to neutral, however 2 participants agreed strongly. Considering “trust in the system”, most of the responses were in the middle, i.e. close to neutral, neither agree or disagree, with 2 participants agreeing strongly.
Most participants found the system easy to learn and use, and not unnecessarily complex. They were confident using the system and they would use the system frequently. However, there was not strong support to the statement that the “various functions of the system were well integrated” and there was not much disagreement with the statement that “there was too much inconsistency in this system”.
The total System Usability Scale (SUS) score is 80 which is considered high usability. On the Usefulness/Satisfactoriness scale, the system was perceived as useful (“useful”, “good”, “effective”, “assisting” but not “raising alertness”) and partly satisfactory (“pleasant”, “nice”, but not “desirable” or “likable”).
Considering the HMI solution, the participants found that it was easy to activate the function with steering wheel paddles, they found the way to turn on and turn off the system intuitive and they felt safe when enabling the system. The participants felt acceleration and braking while the car drove itself comfortable. Concerning “the comfort of the steering while the car drove itself” and “how good the system was to drive the car on the whole,” there was a wide variance of answers and the “mean” answer cannot be differed from “neither comfortable nor uncomfortable”. The participants found that, the information given in the displays was understandable and the information given in the displays was not distracting.
The participants’ answers indicate that they are not fully aware of the system’s limitations. There are clear expectations in decreased fuel consumption and increased driving comport among the respondents. The participants estimated the highest usage rate of the system on motorways in their everyday driving. The majority of the participants indicated that they would be willing to pay between 10,000 and 40,000 SEK for purchasing the system.
Answering the question about what they would do while “driving” the autonomous car regularly, a wide range of answers were given, i.e. from full monitoring of driving to completely relaxed presence and doing other things than driving related activities.
Some worries were expressed about relying on the system in real traffic – “does the car constantly handle new and different situations consistently in real traffic with a lot of drivers around who cannot drive a car and do a lot of stupid things”. Also, one respondent felt that driving pleasure disappears with automated driving.


Enheter & grupper

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Teknik och teknologier


  • Driver Assistance System, AUtomated driving, user acceptance, user experience, Evaluation
Bidragets titel på inmatningsspråkAnvändarrelaterad utvärdering av Traffic Jam Assist-system
FörlagAdaptIVe Consortium within the EU 7th Framework Program
UppdragsgivareEuropean Commission
Antal sidor27
StatusPublished - 2017 mar 31

Bibliografisk information

Department of Technology and societey, Lund University, Sweden