Medical history/driving history

The clinical evaluation starts with a thorough interview of the client’s medical history and the etiology of the client’s disability. The clinician carefully evaluates congenital, pathological, and traumatic conditions that may impact the physical function for driving. The DRS should inquire about the client’s history of seizures and episode status if seizures have occurred, history of dizziness, and visual changes. The DRS must comply with each state’s DMV rules as they relate to physical visual and psychological conditions. If there are areas of concern, the DRS should refer the patient to a specialist for the condition in question to gain possible clearance for driver training or to learn recommended driver restrictions.

The interview should include driving history, including past experience of operating motor vehicles, all-terrain vehicles, motorcycles, and heavy machinery. Understanding the client’s driving history can give the DRS valuable insight as to which adaptive methods and equipment will best suit the client. The client’s driving history also can help determine which clinical assessments should be administered during the driving evaluation.

Vision

A visual screening should be completed to ensure that the client meets the state’s minimum requirements for distance acuity, contrast sensitivity, glare recovery, and peripheral vision. Ocular motor skills should be screened to determine ability to track, fixate, and perform saccadic eye movements necessary for visual search. Testing might include various scanning tests. Screening equipment should be chosen that is accepted and used by the state’s DMV where applicable. Clients who do not meet the legal vision requirements should be referred to a vision specialist for evaluation.

Cognition/perception

The DRS should perform various standardized assessments to gauge simple, divided, and selective visual attention as well as the client’s comprehension of multistep directions. The DRS should evaluate perceptual abilities that have a functional impact on driver performance, including visual closure, visual memory, figure ground, spatial relations, position in space, midline orientation, visual attention, and visual processing speed. Specific tests that evaluate these abilities include the Motor Free Visual Perceptual Test Version 2, Line Bisection Test, Trails Making B, Topographical Orientation, and Useful Field of View. It is important to assess perceptual skills so that functional outcomes that may affect safe vehicle operation, such as lane position, negotiation of curves, parking, merging and lane changes, ability to preplan, and problem solving ability in varied traffic levels, can be accommodated. Areas of concern with these skills may indicate a deficit in risk management skills as they relate to motor vehicle operation.

If compensation techniques cannot be used for these cognitive skill deficits, appropriate assistive technology devices might be used instead. Using assistive devices may require additional education and training in how they interface with vehicle operation. Persons who have difficulty with topographical orientation may benefit from technology such as navigational systems, global positioning satellite systems, and cell phones. Once these components are programmed, the DRS will carefully design a treatment plan that facilitates a gradual increase in complexity as the ability of the driver improves, as well as internalization of these compensatory driver behavioral skills. The on-the-road evaluation then can be appropriately tailored to enhance the evaluator’s ability to assess if the driver is able to compensate for the cognitive/perceptual skill concerns identified in the clinical evaluation.

Physical/functional ability

Driving ability and safety depend on both cognitive and perceptual acuity, but the client’s physical ability is equally important. Therefore, the DRS should assess the client’s physical abilities during the clinical evaluation. The following physical systems should be observed during the clinical evaluation:

In addition, the DRS should assess the client’s ability to transfer independently to the vehicle. If the client uses a mobility device, such as a scooter or a wheelchair, the DRS should assess the client’s ability to load and unload his or her mobility device into a vehicle independently. All of these factors will influence the DRS’s selection of method and any equipment to be used for the on-the-road evaluation. (Please refer to chart Fig.49-1 on function/mobility needs/vehicle for how these areas all must be considered when looking at driving). Physical function will also help determine the proper route and traffic level during the on-the-road evaluation.

Fig. 49-1 Chart detailing safe interfacing of function and ability, mobility device, and vehicle is a crucial factor in creating safe independent drivers.

(Courtesy Shepherd Center, Atlanta, GA.)