After informed consent, participants performed up to 2 practice sessions within the virtual driving course. Participants reported their level of comfort and sense of being in control in the VRSIM during practice based on which a value between 1.0 and 4.0 was selected for the linear and angular speed gains in VRSIM. In addition, participants were asked to select a different pre-programmed driving profile on their wheelchairs (e.g. "indoor" profile), which was similar to their everyday driving profile to obtain optimum driving speed. Optional breaks for 5-10 minutes were provided between driving sessions. For both the PC and VR screens, participants drove through the complete driving course: two trials with the Rollers ON driving mode, one trial with the Rollers OFF driving mode, and one trial in the real-world PMRT driving course constituted to a total of 5 driving conditions (Table 1). A balanced randomization scheme was used to set the order of the five driving conditions.