Chapter 49 Driving and related assistive devices
Driving is a complex, multisensory task that requires physical skill and coordination as well as cognitive understanding of the rules and responsibilities that accompany it. Learning to drive is a challenge for everyone. To drive safely, everyone must learn the basic rules of the road and how to handle various driving situations. Primary and secondary controls allow safe maneuvering of the vehicle. A disability may impact the driver–control interface. When a person with a disability must use the primary and secondary controls differently, special modifications and training are necessary once the driver’s ability has been assessed.
Primary controls include the steering wheel, accelerator, and brake. Secondary controls can be divided into two groups. The first group includes the ignition, shift, headlights, and any system that should be used while the vehicle is stationary. The second group, referred to as the driving systems group, includes the turn signal, horn, dimmer, wipers, and any system used while the vehicle is in motion. Many types and styles of primary and secondary controls can be matched to a client’s abilities. Through driver evaluation, training, and appropriate modifications, a person with a disability may be able to be a safe and independent driver.
Generally, driver evaluations and driver training for people with disabilities are performed by a driver rehabilitation specialist (DRS) or certified driver rehabilitation specialist (CDRS). A DRS specializes in driver rehabilitation services for individuals with disabilities. The CDRS should have basic education in these skills. A CDRS is certified through the Association of Driver Rehabilitation Specialists (ADED; formerly the Association for Driver Educators for the Disabled) after passing a skills test. This certification indicates that the individual has basic knowledge, has fulfilled certain requirements, and is responsible for maintaining skills through continuing education.
Funding sources for driver evaluation and training are explored with the client during the intake procedure and preassessment. In many cases, traditional health insurance coverage for outpatient occupational therapy funds the clinical evaluation. The cost of on-the-road evaluation, training, and equipment may be funded through vocational rehabilitation services, state-funded trust funds, or other charitable organizations. If the disability was incurred as a result of a work injury or motor vehicle accident, insurance benefits may cover the driver rehabilitation and equipment costs if the client is approved by a referring physician.
Either a DRS or a CDRS can evaluate a client to determine whether the client is a candidate for driving. Once this determination has been made, a DRS or CDRS can recommend the type of adapted driving equipment that will best meet the client’s needs. Choosing the appropriate vehicle to modify and installation of the adaptive equipment are done in partnership with a vehicle modifier who is a member of the National Mobility Equipment Dealers Association (NMEDA). It is through the teamwork of this group of professionals that the needs of the client can best be met.
A comprehensive driver evaluation can be obtained by making a referral to a driver rehabilitation program. Most referrals are generated by the physician treating the individual with a disability or functional limitation. The driver rehabilitation program should include a multidisciplinary team with specialized training and certification in driver evaluation for people with disabilities. The comprehensive team includes a driver educator and/or occupational therapist with driver education credentials and access to assistive technology practitioners and wheelchair seating specialists. This team completes a clinical evaluation and an on-road evaluation to determine safe vehicle operation and potential risk management. The team prescribes the appropriate adaptive driving equipment for safe independent driving. Referrals are given for possible funding sources and qualified vendors who can install the prescribed modifications to the client’s vehicle.
A clinical evaluation of prerequisite skills for safe motor vehicle operation comprises several main skill components. Depending on the state, a DRS may have received licensure from the state’s department of motor vehicles (DMV) and professional boards. A DRS with diverse experience in the treatment of persons with physical, visual, and psychological disabilities is best equipped to complete the clinical evaluation. The following are common areas that are evaluated during the clinical evaluation.
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.
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.
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.
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.
Once the clinical evaluation has been completed and the client remains eligible for driver training, the client should be taken on the road for an on-the-road assessment by a qualified DRS. The clinical evaluation helps determine which vehicle and driving equipment, if needed, will be used for the driving portion of the evaluation. This on-the-road evaluation is dynamic and may include changes in equipment and configuration as more information is gathered during the on-the-road assessment. During the on-the-road evaluation, speed control is evaluated. Coordination of gas and brake, hill starts, range of speeds, stop locations, and following distance all should be tested. Steering is evaluated, including execution of turns, lane tracking, and lane corrections. Operation of secondary controls, ability to park, ability to change lanes, ability to follow the rules of the road, judgment, risk management, problem solving, and endurance are part of the evaluation. It is important to remember that the on-the-road portion of the evaluation must be graded to the ability of the driver. Assessment of the client’s ability to drive in residential areas, on secondary roads, and on limited access highways will depend on the driver’s ability. Further training may be a recommendation resulting from this evaluation.
For most individuals, training will be required to master the skills for safe operation of adaptive driving equipment or methods. The process for training should be individualized for each client’s skill level. A new driver will require an average of 40 hours of training, but an experienced driver may require only 5 to 10 hours of training. A DRS will determine the driver rehabilitation training plan upon completion of the initial driver evaluation.
The driver training process focuses on safe motor vehicle operation with or without adaptive driving aids, proper scanning techniques, and risk management skills. Educational videos, simulators, textbooks, and homework assignments often supplement behind-the-wheel training sessions. A skilled DRS develops formalized routes that will teach all skills required to pass the DMV state road test.
Traffic routes are an important component of the training process. Routes are graded from simple, low-traffic environments and to complex, high-traffic levels and expressway driving. If the client is unable to progress successfully through these routes to achieve full skill mastery, the treatment plan can be altered to allow driver training in a familiar area. This may result in recommendations for driving restrictions to a particular mile radius, time of day, speed limit, or roadway type.
High-technology driving systems (e.g., servo controls, discussed below) will require a minimum of 40 hours of training. This time will allow the DRS to develop a comprehensive vehicle modification prescription that will optimize the fit of the wheelchair mobility device with electronic primary and secondary controls. Wheelchair lock-downs, lift systems, and vehicle structural modifications, including lowered floor, raised roof and doors, and seat modifications, all will become specifications for the client’s vehicle prescription. Once the client’s vehicle is completed, a DRS will complete a fitting at the vehicle modifier’s shop, and final training hours in the modified vehicle will be done after the fitting is completed.