## 8 General Discussion  
Implementing driving simulators as a tool in clinical settings can offer clinicians standardized protocols with objective performance metrics to assess their client's driving-related performance skills in a safe environment. Driving simulators can effectively be used for assessment, training and rehabilitation. Using tools like Functional Object Detection Advanced (FOD-A) allows clinicians to modify the difficulty level of tasks in order to provide interventions to target specific deficits. The purpose of Study 1 was to determine the rank order difficulty of four FOD-A driving simulator scenario combinations. Study 1 was able to rank order three of the four FOD-A tasks. This is beneficial for clinicians who are training clients to have guidance on where a given client should start versus finish their training. Out of the possible simulator variables, three are likely to be the most beneficial for the majority of clients; therefore, clinicians should first evaluate the client's average target E reaction time, then the percent of Es accurately detected, then the average brake reaction time. This is helpful to be able to give guidance to clinicians, especially new clinicians, on how to prioritize the results for assessment, training, and rehabilitation purposes.  
In Study 2, one combination of FOD-A compared the senior to teen drivers which demonstrated age-related changes in driving metrics. Using statistical techniques examining numerous simulator performance variables, four variables can be used to determine or classify if a driver is a teen or senior with 78% accuracy. FOD-A requires a driver to stay in the center of their lane, maintain the posted speed limit, react to a lead vehicle, and detect objects in the periphery. These four key variables demonstrate the importance of central vision (detecting the brake lights in front of you), peripheral vision (detecting stimuli across your visual scene), and being able to react quickly using one's hands and foot. What is especially encouraging about these variables are the high face validity for patients and their families.  
From a safety perspective, a key benefit of driving simulators is that clients can repeat tasks in a safe, standardized manner, which is simply not possible when using a naturalistic driving evaluation. Considering the growing number of senior drivers, it is also encouraging that these tasks are scalable. Simulators allow other key individuals (e.g., family and healthcare providers) to observe the client in a safe environment. This has been beneficial for a broad range of circumstances including understanding the impact of glaucoma, macular degeneration, left side neglect, as well as parents gaining insight into a potential driving career for young adults with developmental disabilities. While future studies are needed to understand the impact of specific diagnoses on driving performance, this baseline performance data of healthy teens and older adults provides a foundation for future research and clinical activities.  
The key contribution of this work is the demonstration that customization is possible using FOD-A and enables clinicians to assess and rehabilitate driving-related skills across a broad age range of diverse client populations, addressing an existing gap. Unlike on-road driving assessments, simulators provide measurable, repeatable scenarios, which can be tailored to specific cognitive and motor skills, enhancing clinical precision and intervention.