This study has an experimental, repeated measures design with validity and reliability testing. In Phase 1 of the study, we designed and developed the software needed to deliver the computer-based and VR-based testing environments. In Phase 2 of the study, we improved on the design iterations of Phase I, recruited a sample of 31 Electric Power wheelchair (EPW) users and delivered the simulator based driving assessment using a pool of clinicians to assess the reliability of system in real world and in the virtual environments.