Australian Study on Cooperative ITS Technologies Showed a Four to Nine Percentage Point Increase in Technology Usefulness Rating, Based on User Questionnaires Comparing Control and Treatment Groups.

Ipswich Connected Vehicle Pilot Project Deployed in Queensland, Australia Assessed Self-Report Data based on Questionnaires, Interviews, and Focus Groups.

 

Date Posted
12/18/2023

Ipswich

Ipswich, Queensland,
Australia
Identifier
2023-B01811
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Ipswich Connected Vehicle Pilot Summary of the Subjective Evaluation Study Findings

Summary Information

The Cooperative Intelligent Transport System (C-ITS) technology allows vehicles to communicate with other vehicles, roadside infrastructure, and transport management systems in real-time, providing road users with information or visual warnings, on a dedicated Human Machine Interface (HMI). This study summarized the details from the Ipswich Connected Vehicle Pilot (ICVP), specifically the part which entailed a set of subjective self-report data based on four questionnaires with over 300 participants each, interviews with 53 responses, and focus groups with 47 participants, occurring over various data collection time points, involving six separate C-ITS technologies. The ICVP lasted from September 2020 to September 2021, with a total of 355 public participants in Ipswich, driving their own vehicles retrofitted with C-ITS technology, for a duration of nine months throughout the year-long pilot period. Of the 355 ICVP participants who completed the mandatory questionnaires, 100 (53 plus 47 previously mentioned) also participated in the optional interviews and focus group studies, providing qualitative findings.

METHODOLOGY

The participants were randomly assigned into either of two groups: Treatment Group that had an HMI receiving warnings, and Control Group that had an inactive HMI. Over nine months, both objective (driving) and subjective (self-reported) data were collected using a counterbalanced between-groups methodological design (i.e., baseline- or intervention- first conditions) with random allocation, regardless of the experimental group. Participants experienced safety information or warnings based on six different technologies presented in Figure 1.

Figure 1. Six C-ITS technologies tested in ICVP

Six C-ITS technologies tested in ICVP: (i) Advanced Red Light Warning (ARLW), which alerted the driver about an impeding red-light violation on their part at a signalized intersection , (ii) Back of Queue (BoQ), which alerted drivers when travelling at an unsafe speed for an upcoming traffic queue, (iii) In-Vehicle Speed (IVS), which informed drivers about prevailing speed limits, (iv) Road Hazard Warning (RHW), which alerted drivers when travelling at an unsafe speed for a hazard up ahead, such as wet pavement or a crash, (v) Road Works Warning (RWW) which alerted drivers when travelling at an unsafe speed for upcoming road works, as well as warned drivers when exceeding the speed limit within the road works, and (vi) Turning Warning Vulnerable Road user (TWVR), which alerted drivers about pedestrians or bicycle riders potentially crossing at an upcoming signalized intersection.

FINDINGS

  • The results showed a four to nine percentage point increase in technology usefulness rating, based on the grand (or pooled) mean of the four questionnaires across six different C-ITS technology uses cases, comparing treatment and control groups. 
  • Uniformly, over the four questionnaires, treatment participants rated IVS as the most useful technology. 
  • RWW-Speed technology use case revealed the highest improvement (nine percentage points), comparing the control and treatment groups’ grand means for the four questionnaires for this technology.
  • Over 65 percent of participants indicated that none of the individual use cases should be removed, implying they could see benefit in all of them.
  • Results from the interviews and focus group surveys produced qualitative findings only, but still, the results were in agreement with the ones obtained from the questionnaires; the IVS technology was perceived most positively. 
  • Interviews also revealed that the participants found C-ITS a beneficial idea in general but stated that further development and increased accuracy was needed to improve road safety.

Results Type
Deployment Locations