Low-Fidelity Driving Simulator Training in Parkinson's Disease.

SDLP refers to the mean Lane position of the driver's vehicle to the roadway centerline (defined as zero). The center of the vehicle is the reference point. Positive values indicate lane positions on the right side of the road; negative values indicate left. Default roadway lane widths are 12 ft (3.66 m) across; therefore, values close to 6 ft (1.83 m) indicate positioning near the center of a lane.

The Adelaide Driving Self-Efficacy Scale is a self-reported assessment of participants' beliefs in their capability to organize and execute actions towards safe driving. It is a 12-item questionnaire that measures an individual's self-perceived confidence in performing various driving-related activities, such as driving in heavy traffic or at night. It uses a 0 (not confident at all) to 10 (completely confident) rating scale for each activity, with total scores indicating overall driving confidence.

The Montreal Cognitive Assessment is a brief screening tool used to detect mild cognitive impairment and early dementia. It evaluates multiple cognitive domains, including attention, executive function, memory, language, visuospatial skills, abstraction, calculation, and orientation. Total score is 30 points.

> or = 26 ---- Normal 18 to 25 ----- Mild cognitive impairment

The Dot Cancellation Test is a neuropsychological evaluation tool used to assess focus, attention, visual scanning, and occasionally motor speed or neglect. It is also referred to as the Cancellation Test or Visual Cancellation Task. The participant is given a page with a random cluster of dots and instructed to cross out (cancel) a particular type of cluster of dots. The investigator calculates the time taken and the number of errors committed by the participant.

The Rey-Rey-Osterrieth Complex Figure Copy Test is a neuropsychological tool used to assess visuospatial constructional ability, planning, and organizational skills. The individual is asked to copy a complex geometric figure, and their drawing is scored based on the accuracy and placement of 18 specific design components. The score ranges from 0 to 36. A higher score indicates better performance.

The Trail Making Test is a paper-and-pencil assessment used to measure attention, processing speed, and executive function. It has two parts: TMT-A, where individuals connect numbers in sequence (1-25), primarily tests visual scanning and processing speed. TMT-B requires alternating between numbers and letters in order (1-A-2-B, etc.), placing greater demand on cognitive flexibility and set-shifting.

The Snellgrove Maze Task is a paper-and-pencil test designed to screen for cognitive and executive function impairments that may affect safe driving. The participant is asked to navigate a complex maze as quickly and accurately as possible without lifting the pencil from the page. Performance is measured by time to completion and number of errors (e.g., wrong turns, dead ends). Longer times and higher error counts are associated with poorer executive function.

The Stroke Driver Screening Assessment (SDSA) is a standardized battery of paper-and-pencil tests developed to predict fitness to drive after stroke or other brain injuries. It includes subtests such as Dot Cancellation (visual attention), Directions Test (visuospatial and executive skills), Road Sign Recognition (memory and comprehension), and Compass Test (spatial orientation).

Divided attention in simulator evaluations refers to a driver's ability to manage driving tasks while simultaneously responding to secondary demands, such as detecting shapes. Performance is typically measured by reaction time, accuracy of responses, and driving stability (lane keeping, speed control) during the dual-task condition. Poor divided attention scores suggest reduced cognitive flexibility and higher crash risk.

Time to Collision is a safety metric in driving simulator evaluations that estimates how long it would take for a driver to collide with a lead vehicle or hazard if both maintained their current speed and trajectory. A shorter TTC indicates less available reaction time and a higher crash risk. Critical thresholds (often ≤ 1.5-2.0 seconds) are used to identify unsafe or delayed responses.

Navigating intersections in simulator evaluations assesses a driver's ability to manage visual scanning, hazard perception, decision-making, and vehicle control while navigating an intersection. The performance is measured by gap acceptance.

Complex Brake Reaction Time in simulator evaluations measures how quickly a driver can detect an unexpected hazard, process the situation, and apply the brake in a more demanding context. Longer Complex Brake Reaction Time indicates delayed hazard response and higher crash risk.

Driver mistakes, such as the number of collisions, the number of lane positioning errors, total number of tickets, will be recorded during the simulator drive assessment. Higher scores indicate poor driving performance.

The Test Ride for Investigating Practical Fitness to Drive is a structured driving simulator assessment developed to evaluate the practical fitness to drive of older adults and individuals with medical conditions. Total items are 49 scored on an ordinal scale of 1-4. Total score is 196. A higher score indicates better driving performance.

The Driver Comfort Questionnaire is a self-report questionnaire designed to assess how comfortable and confident individuals feel in different driving situations. It is scored between 0 and 100 percent. A higher score indicates a higher comfort level of driving.

The Driving and Riding Avoidance Scale is a questionnaire that measures the extent to which individuals avoid certain driving or riding situations due to discomfort, anxiety, or reduced confidence. There are 20 items in this questionnaire. Each item is scored 0-4. A lower score indicates less avoidance behavior.

A self-reported Daily Driving Log, manually entered in a journal by each participant, will be collected to analyze driving patterns during the study period.