Driver Rehabilitation and Personal Transportation:

The Vital Link to Independence

Carol Beatson, Dip OT, NZROT

Approved Driving Instructor - (Advanced)

Driver Assessment Service, Auckland, NZ

Rosamond Gianutsos, PhD, CDRS

State College of Optometry, State University of New York, NY, NY

Address correspondence to:

Rosamond Gianutsos, PhD

Cognitive Rehabilitation Services

38-25 52nd St

Sunnyside, NY 11104-1027

voice/fax 718 457-7483

e-mail: cogrehab@pipeline.com (RG)

and carolb@clear.net.nz (CB)

Special appreciation is due to Michael Bannister whose talents and contributions are many, to gerry@pipeline.com for assistance with graphics and to Amy Campbell, OTR/L of the Easter Seals Mobility Center in Meriden, CT for her colleagial input, data collection and allowing us to photograph.

To appear as Beatson, C. & Gianutsos, R. (1998) Personal transportation: the vital link to independence.Ch. 47 In M. Grabois, S.J. Garrison, K.A. Hart, & L.D. Lehmkuhl (Eds.) Physical medicine and rehabilitation: The complete approach. Blackwell Science, Inc., in press.

TABLE OF CONTENTS

A. INTRODUCTION

Summary and aims of chapter

Frames of reference

B. DRIVER REHABILITATION CASE EXAMPLES

C. THE ASSESSMENT PROCESS

Off road screening approaches

D. COMMUNITY INTEGRATION

Environmental data

Terrain

Climate

Behavioral

Ethical and legal issues

LIST OF ILLUSTRATIONS

LIST OF TABLES

INTRODUCTION

In technically advanced societies, driving has become an integral part of daily living for all aspects of adult life. For people with disabilities, whose mobility has become severely curtailed, driving represents the ultimate freedom; the means by which to attain their highest level of independence and autonomy over their lives.

On the other hand, medical and health professionals have a responsibility towards society as a whole as well as towards the person with a disability to ensure that the best advice is given regarding safe control of an automobile. Weighing up the issues involved is often a difficult task for medical and health professionals. It calls for sensitivity and diplomacy and an understanding of the disability and its progression. As well as medical and functional information, knowledge of the person’s level of insight and the likelihood of their displaying responsible behavior, as a direct result of their disability, or originating from their actual personality traits will have a bearing on the final recommendations regarding the advisability of driving. Despite extensive research, no firm conclusions have been drawn on which specific cognitive deficits may constitute a barrier to driving. However, literature shows a consensus of the need for assessment to be carried out on several levels, including medical, psychological, functional and, if deemed safe to do so, an on road drive. The difficulty of separating individual skills as predictors of actual performance is recognized by Evans (1) who nonetheless comments that "perhaps a distinction should be made between perceptual-motor skills and total performance".

In comparison to the attention given to assessing brain injured drivers, little emphasis has been found in the literature regarding the driving safety of those with physical disabilities, but without brain injuries. Those studies which do focus on physical disability demonstrate that, given the correct vehicle adaptations, driving safety is not compromised (2-5).

This chapter aims to provide an introduction to the issues involved in driver assessment for a wide range of disability types. It outlines several models of driving skill theory, examines the steps to be followed when assessing driving skill and discusses aspects of behavior and environment which impinge on the person’s ability to drive safely.

Before approaching comprehensive driver assessment, it is necessary to have a well formed philosophy of what is to be evaluated, what relevance it has to the task of driving and by what process the final decision will be made. Three frames of reference, developed between 1979 and 1992, are examined below. While it appears that the first two of these models have evolved independently of each other, similarities are present in their approach in which the multiple factors that comprise the complex task of driving are described. Because each model adds a different dimension to the issues involved in driver assessment, they are all worthy of consideration. The development of theoretical models in driver assessment will now be addressed through these three frames of reference.

Described by Simms (6), the focus of this model is on the internal processing methods of multiple, constantly changing, incoming visual stimuli by which is the driver is bombarded during the driving task. The person’s driving safety will depend on the rapid interpretation and accurate responses to this information. Comprehensive visual screening, especially in regard to restriction in visual fields, is an essential first step in the assessment process.

Environmental information. The first stage of Simms’ model includes the ability to perceive traffic engineering, advisory signs and roadway design, as well as the presence and movement of other road users.

Attentional and perceptual mechanisms. The second stage of the model characterizes the person’s ability to gather and form the complex environmental information into a meaningful picture within a compressed time frame. Simms comments that essential visual perceptual skills at this level include "scanning, tracking and figure-ground discrimination."

Logical analysis and decision making. This stage describes the ability to interpret information gathered and combine it with already existing knowledge of the driving task in order to make the most appropriate decisions. It involves the continuous, accurate assessment of risk in a wide variety of potentially hazardous situations, which are constantly changing.

Response. The final stage of Simms’ model is the time frame in which the person makes a physical response. A prerequisite is to have accurate control of the vehicle which may require vehicle modifications as well as, in our experience, full control over at least two out of four limbs.

This model is hierarchical in that each level impacts on the other, thus affecting the way in which the driver performs. "Dealing with Danger," an unpublished summary report by Michon of a workshop in 1979, described a three tier model of driving skill. Michon’s report was outlined by van Zomeren et al, in 1987 (7).

Strategic level. The first level of Michon’s model describes the skill of planning the drive in advance. It involves making decisions about the best route to take, what time of day is preferable, anticipated traffic density, expected weather and the level of wellness or tiredness of the driver. As the person is not yet behind the wheel, the pressure of time required to make decisions on the strategic level is low. It also involves more global decision making, e.g., whether to spend the extra money for antilock brakes and dual airbags - even where to live and work. Clinical experience has shown the importance of understanding the driver’s ability to address the strategic level, especially among those who lack insight about their actual abilities or who do not acknowledge their failing level of health.

Tactical level. Skills in the tactical level involve the driver’s actual behavior while driving and decisions on which these are based. Examples offered by van Zomeren et al (7) include "adapting one’s speed when entering a residential district, switching on the headlights when rain reduces visibility, or deciding to pass another car". The time frame in which to respond at the tactical level is moderate. In psychological terms, the tactical level is a very broad description of function. Inasmuch as the tactical level calls for prospective thinking and action, there is an emphasis on the first three levels of Simms’ model (environmental information, attentional and perceptual mechanisms, logical analysis and decision making). The outcomes of faulty cognitive mechanisms have been clarified by van Zomeren et al (7), thus adding another dimension to the approaches outlined in Simms’ model. Impairments on the tactical level may include "impulsivity [which] is attributed to disinhibition or reduced cognitive control". "Poor judgement"..."derived from poor estimation of risks and inadequate adaptation of speed to traffic conditions".

Operational level. The final level of Michon’s model includes the automatic decisions and practiced responses of a driver. It involves the ability to position the vehicle and steer it accurately, use the primary and secondary driving controls, monitor and avoid potential hazards both in the present and a few seconds ahead. Impairments in the operational level are listed by van Zomeren et al (7) as falling "into five general categories: (1) inadequate visual scanning of traffic and environment, (2) problems in spatial perception and orientation, (3) poor tracking, (4) slowness in acting and (5) confusion when more complex actions have to be carried out". The operational level encompasses the last two levels in Simms’ model (logical analysis and decision making and response). The time frame in which to respond at the operational level is limited and an ever-present factor.

The Michon/van Zomeren model is less about skills than about the driving task and, therefore, the skills identified by Simms will find expression at both the tactical and operational levels. Further, the Michon and van Zomeren’s model has interesting implications for on road assessment. First, an explicit attempt should be made to address the tactical level. For instance, one might ask the person to find a way to reverse direction ("Oops, we should have gone the other way...") or to find a safe way to pull off the road. Second, the strategic level needs to be addressed, but, by definition, it can not be while driving.

A study in 1991 by Galski, Bruno and Ehle (8) has considered elements of the earlier frames of reference and further refined them. They have gone one step further than developing a hypothetical model and investigated its effectiveness in clinical practice. The researchers tested the Cybernetic Model for its use in evaluating fitness to drive after brain injury and report predictive validity of the model. The Cybernetic Model is complex, featuring layers of skills that continuously interact with each other.

General driving programme. This level holds knowledge of the road rules as well as learning from repeated past experiences of driving. It is not a static body of knowledge but rather a changing database of information that is constantly updated by new experiences. "It initiates and directs all driving related activities" in routine and repeated situations(8). In this sense, the general driving program is an expansion of Michon’s tactical and operational levels. Impairment of the general driving programme may derive from loss of memory for past learning or reduced ability to use past learning in new situations.

Executive component of the general driving programme. The executive component is activated by the intention to drive. It guides the preparatory activities for driving and signals the calculation and construction coprocessor to become active.

Specific driving programme. As a decision has now been made to drive, this level organizes the elements of destination, route etc., as described in Michon’s strategic level. In addition, the specific driving program directs four additional systems to commence operation.

Sensory input: The scanning of global information being received from the body’s visual, auditory, proprioceptive and kinaesthetic sensors. Whereas routine driving requires a low demand on this level, new situations demand more precisely directed sensory monitoring. Impairment may create delays in processing.

Calculation and construction coprocessor: In order to interpret the ever changing three dimensional environment, the driver makes use of this level to "calculate, integrate and coordinate the incoming sensory information" (8). This involves visual-perceptual skills including "distance, depth, spatial relationships, velocity and gradients.." (8).

Motor output: Similar to Michon’s operational level, motor output includes the physical tasks of vehicle control, such as steering, braking and accelerating. In addition, Galski et al (8) have refined the concept by considering the need to perform a single action, or a combination of actions as well as the degree of effort required to ensure safe passage of the vehicle.

Resident diagnostic program: The final level checks the entire system’s function. It is a generic system covering "cognitive-perceptual-physical skills, executive processes (e.g., planning, goal setting, monitoring performance, regulating behavior) and psychological factors (e.g., personality, emotions, beliefs) in all activities" (8). Impairment in this area is likely to affect insight into one’s own abilities and reduce safe driving behaviors.

DISABILITIES AND CASE EXAMPLES OF DRIVER REHABILITATION

A broad spectrum of disabilities / conditions is served by driver rehabilitation and if there is any subdivision, it has to be the presence of (1) physical disability and (2) cognitive impairment. These are summarized in Table 1 together with remarks and observations based on our clinical experience. The wide scope of disabling conditions and their impact on driving often present unique challenges to persons who would be Driver Rehabilitation Specialists. We have chosen two of our more complicated cases to illustrate what can be involved and what can be accomplished. The first, whom we shall call "A" was treated by CB in New Zealand, which will account for the steering wheel positioned on the right side of the vehicle. He had physical disability secondary to spinal cord injury. The second case, "B", was treated by RG for cognitive and behavioral sequelae of a severe traumatic brain injury. Parts of his case have been reported elsewhere (9). Together, they represent the two broad domains of disability, physical and cognitive, which are of concern for driver rehabilitation.

Once his condition had stabilized, "A" was admitted to a spinal rehabilitation facility for rehabilitation. For driver assessment, this meant that his abilities did not remain static and gradual recovery occurred over several months, making it difficult to predict his final vehicle and equipment needs with any certainty. "A" was referred for driver or passenger assessment near the end of his inpatient stay at the Spinal Unit.

Functional ability. "A" initially presented with patchy cutaneous sensory loss and some return of movement in all limbs, but this was not sufficiently functional for walking, driving or independent transfers. He was confined to a wheelchair. At that time, it seemed his only option was to access a van via a wheelchair loader and to travel as a passenger. A further complicating factor was his large body size. This had major implications for driver assessment. It also meant that his occupational therapist and physiotherapist at the Spinal Unit gave special attention to equipment for daily living in all areas, especially wheelchair prescription and housing modifications. They also lobbied "A"’s funding agent to take into account not only his injury but also his ergonomic needs: a complication that hindered his rehabilitation and discharge planning.

Life roles. Prior to his injury, "A" was employed as an Industrial Chemist in a tertiary educational facility. He is married and the father of two 4 year old boys (twins). In order to readjust their lives and to make the most of their earning capacities, "A" and his wife decided to swap roles. "A"’s new role is to organize the care for his children during the day and to continue with distance learning by correspondence at the same time. This meant that he was determined, if possible, to drive. Travelling as a passenger simply did not fulfil his goals as a parent and a spouse.

Improvement in function. "A"’s assessment and follow up continued over a period of 3 months. During this time he steadily progressed to independent transfers and the use of elbow crutches. At this stage, we established that he had sufficient return of movement and upper limb strength to enable him to use hand controls on a car with power steering. Therefore, the remaining obstacles to driving were (a) how to stow an outsized fixed frame wheelchair and (b) what vehicle to choose. (see Figure 1)

Vehicle selection and teamwork. With supervision from his occupational therapist at the Spinal Unit, "A" quickly established that he was unable to stand up from a standard car seat. Furthermore, even though he is tall, he was unable to access the seat of 4 wheeled drive vehicles which were too high. Eventually, "A" discovered that the range of "people movers", a van-shaped car, seemed ideally suited to his needs. They were more than twice the cost of the available car purchase grant.

Static assessment of the first car was conducted with "A", his occupational therapist, the driver assessor specialist (OT) and a vehicle modifications engineer. Although he could easily get into and out of the driver’s seat, we found difficulties with seat positioning, and the potential creation of pressure areas on his thighs from the hand brake on one side and the contours of the driver’s door on the other. It would require substantial modification. Another make of a similar vehicle was identified, which had substantially more leg room, better seating support and which could be modified at less cost. (see Figure 2)

Vehicle modification and teamwork. "A" lives in the suburbs of a large city and would principally be driving for short distances on sealed roads in relatively busy traffic. As a family, they would like to travel further across the city on the freeway or out of town for vacations in rural areas. Both journeys require travelling at high speeds, which would affect the stability of an externally mounted, outsized fixed frame wheelchair, which would essentially act as a large sail on top of the car. Discussions with the manufacturer of a car top wheelchair carrier about safety risks decided us against this modification. Instead, we agreed that, although it was not ideal, "A" should aim to stow the wheelchair in the level access trunk, while seated safely at the opening to the trunk.

The following vehicle modifications were identified at a further follow up assessment, with an additional team member: a vehicle upholsterer.

Due to his size and special needs, we had not been able to place "A" in an adapted vehicle to test his practical driving abilities. Therefore, on collection of the vehicle, "A" was given driver education, concentrating on the safe use of hand controls. He quickly understood their use and within 40 minutes, "A" was driving the vehicle as though he had had plenty of practice.

This project has aided "A"’s return home and has been integral in re-establishing a normal life following severe spinal injury. He regularly uses the vehicle to transport his sons to and from school and has enjoyed short weekend visits to the country. He is able to stow his wheelchair in the trunk, while maintaining his balance and has not found any difficulties achieving this on a variety of terrain. "A" has returned to the workshop on one occasion to add a further vehicle modification, which we had overlooked. On those days when he felt unwell, and needed to visit his doctor, it was difficult for "A" to access the front passenger seat. Therefore, the seat was also positioned 75mm further back to allow him sufficient leg room to travel as a passenger in addition to being a driver (see Figure 5).

"B" survived a head-on collision with multiple trauma, including orbital and skull fractures and massive brain injury. He was evaluated and treated with an individualized technology-augmented cognitive rehabilitation program, in which driving was an important, but by no means the only component.. By the time he was first seen a year post onset, he was ambulatory and expressed (solo and a capella) great confidence in his ability to drive. His family did not trust his judgment to stay at home alone for anything other than short intervals and he was totally dependent on others to drive him where he needed to go. It never ceases to amaze us how often people who are not safe in crossing the street on foot (or in a wheel chair) seek to drive. Initially, "B"’s obsession with driving was directed to mobility on foot and public transit. With supervision and safety awareness training to become independent on the train (see Figure 6). This achievement was psychologically uplifting and he continues to use this mode of travel on longer trips, especially into urban areas.

"B" would have angry outbursts and poor frustration tolerance. On each such occasion he would attest to having learned his lesson, that the problem would not occur again. He was pursuaded that he had to earn the confidence and trust of others – that his own confidence was not sufficient, as his judgment was always to be "optimistic" rather than realistic. He agreed that he would have to remain outburst free for at least three months before he could expect others to find him sufficiently trustworthy to even consider assessment for resumption of driving. It took him 9 months to achieve reach this goal.

"B" had significant attentional problems (e.g., with simultaneous information processing and mental flexibility), binocular dysfunction (affecting depth and other forms of visual perception), impulsivity and visual agnosia (failure to recognize some objects in his direct line of sight). These problems were addressed in his cognitive rehabilitation and optometric treatment programs. Some exercises were identified for their specific relevance to skills needed for safe driving, for example, visual closure. These exercises showed him concretely the standards which he needed to meet and demonstrated that others were taking his goal of driving again seriously.

Throughout this time, the clinician’s observations of "B"’s reasoning and behavior were complemented by information offered by family members and other professionals. It was clear that much improvement was needed before "B" would garner family support for his driving. Formal pre-driving assessment was initiated gradually and explicitly made contingent on achieving consistently acceptable behavior and judgment.

Since "B" was under optometric care, formal vision screening was not needed; however, his binocularity problems were identified as potential issues for judgment of distances, e.g., following and stopping. His visual perceptual agnosia was characterized as a "look no see" problem, regularly brought to his attention in whatever contexts it occurred, and explicitly related to driving, e.g., "gee, Officer, I didn’t even see him…"

Formal assessment of judgment and information processing abilities related to driving was accomplished with the Elemental Driving Simulator (9), illustrated in Figure 7. On this rudimentary computer-based simulation, performance relative to a norm group of drivers is compared to self-appraisal. "B" predicted that he would score average or better on all scales; however, it took him four attempts, separated by at least a month, to attain scores on all subscales within two standard deviations of the mean – a clinical cutoff corresponding to the 2nd percentile.

An on-road behind-the-wheel assessment was then scheduled and as it happened "B" was observed by two experienced Driver Rehabilitation Specialists (DRS), one of whom recommended further Cognitive Rehabilitation and the other thought it was time to begin driving lessons. Although he had already made great progress, "B" was still a marginal candidate for driving. Once authorized by his insurance carrier, "B" began lessons with a local commercial driving school instructor who was experienced with drivers with disabling conditions. As coordinating DRS, I (RG) observed the first lesson, which also served as an independent evaluation, and remained in close communication with the driving instructor. After two months of lessons, the instructor encouraged "B" to begin practice driving. His family was not eager to work with him in this regard and "B" was to obtain his own car, insurance and satisfy legal requirements (his license, by now, had expired and he had to notify the licensing authorities of his condition and obtain medical clearance to continue driving – see Appendix 1 which details the applicable legal requirements. He obtained an oversized center-mount rearview mirror (See Figure 8).

His practice and guidelines for driving now came into my direct oversight as DRS. The following system remained in effect for approximately one year before "B" achieved a modicum of meaningful independence in his driving.

LEVELS OF ASSESSMENT

With these examples in mind, we turn now to a systematic consideration of assessment of driving competencies and adaptive equipment needs. Specialist assessors can categorize the levels of assessment into three main sections:

1) drivers with musculoskeletal impairment, which can be mild to severe. Mild impairment typically involves a range of adaptations to a car, or simply a change of vehicle to suit the ergonomics of the driver’s disability in a more satisfactory way. These drivers can be readily evaluated using an adapted vehicle, which is essential equipment within a driver assessment program.

Drivers with severe impairment who wish to drive from their wheelchair require a very detailed appraisal of their abilities, a precise understanding of the range of remote controlled driving adaptations available on the market and an understanding of which vehicles are suited to this type of adaptation. As these modifications are costly, careful prescription is needed, taking into account the person’s activity tolerance, muscle strength, trunk balance, range of movement of all limbs and their potential safety while driving. In Britain and the USA, a number of companies specialize in the manufacture and installation of complex computerized, "zero effort" driving controls into suitable vehicles.

2) drivers with cognitive impairment, which can also range from mild to severe. The complexities of assessing the function of a driver with brain damage requires skilled attention when a return to driving is desired. Issues related to ageing drivers whose skills have deteriorated to a potentially unsafe level uncovers a whole range of social and emotional issues which the assessor must help them to begin to face. This aspect of driver assessment requires skilled evaluation and intervention and the support of a team to confirm and implement the assessor’s findings.

3) drivers with both musculoskeletal and cognitive impairment. This involves not only a comprehensive cognitive assessment approach but also specific evaluation for ergonomic fit of a vehicle and adaptive driving controls. It is well to be mindful of the potential for multiplicative impact of disbilities. For example, hand controls may be easy for a cognitively intact person to learn. However, the person with mild cognitive impairments may exhibit excessive attentional constriction, hemi-inattention, or impulsivity when driving with hand controls. For those drivers with variable and deteriorating conditions such as multiple sclerosis and Parkinson’s disease, complex issues arise involving the impact of musculoskeletal impairment on cognitive skills. Specialist assessors and close team work with the person’s family or caregivers and their physician is needed to achieve an acceptable outcome. With a condition which is expected to progressively decline, the DRS should make it clear that the issue is not whether to stop driving, but when and how to do so. Along with the patient and treatment team, the DRS’ job is to identify guidelines for making these decisions.

Although advances have been made in determining which skills affect driving safety, agreement has yet to be reached on the exact assessment battery to use. However, it is here that the multidisciplinary approach has particular value, with an on-road drive as the final advancing vote. Essential team members include a physician, a psychologist, an occupational therapist and a driving instructor, with other specialists, such as an eye care specialist (Optometrist or Ophthalmologist) and Vehicle Modification Engineer on call as needed.

While the literature focuses on providing comprehensive driver assessment services from within a large treatment facility, there is also a trend towards community based assessment services. At this stage, the client’s condition has generally stabilized and they have been, or are about to be, discharged from inpatient residential treatment.

Many drivers with musculoskeletal impairment who are medically stable already reside in the community and seek specialist assessment services as a further step towards independent living. A stable level of function enhances the assessment process. It enables the compilation of a realistic prescription for adaptive equipment which is suited to the individual’s tested and observed abilities. Therefore, it is an advantage to see physically disabled drivers months or even years after hospital based rehabilitation is complete.

In such a setting, the occupational therapist acts as co-ordinator and works closely with the client’s general medical practitioner or rehabilitation team and family to obtain appropriate medical screening in preparation for driving. In community based services, a team structure exists in different facilities, both commercial and service-based, and members are called on at appropriate stages of the assessment and vehicle adaptation continuum. In New Zealand, for example, community based, private occupational therapy services provide a focus of co-ordination for much of the driver assessment services. However, this may only work well in areas with relatively low population density, such as New Zealand (population is approximately 3.5million) (10). A significant advantage of community based services is that it makes it possible to evaluate the potential of persons with some cognitive limitations, who may still be able to drive along familiar routes in their own communities.

In order to reduce the risk to the person with a disability, the assessing staff and the public at large, efforts have concentrated on developing a screening battery prior to going on the road. The following section overviews the approaches to assessment that are commonly utilized in clinical practice and for which research has shown favorable outcomes.

The exact range of off road screening tools which are useful in assessing people with brain injury remain ill defined. However, reliable results are reported in facilities where a multidisciplinary approach has been taken.

Medical fitness. The first level of assessment is by the physician, to determine whether the person intending to drive has a sufficiently stable condition to allow them to drive. If the recommended multidisciplinary driver assessment and rehabilitation services are available, the physician’s emphasis should be on those medical conditions which are not apparent or intermittently produce symptoms incompatible with safe driving. These conditions include epilepsy, problems with cardiac function and circulatory efficiency, metabolic disorders, including poorly-controlled diabetes, visual, neurological and psychiatric disorders. Essentially, the physician is being relied upon to address those conditions which might not manifest themselves on clinical or behind the wheel assessment.

Medical screening guidelines have been developed by medical organizations and are recognized by licensing authorities. Several countries, e.g., Australia(11), New Zealand, United Kingdom, Canada (12), and the United States of America, have manuals containing guidelines on medical fitness to drive, which are usually obtained through the local licensing authorities or the local medical society. While these guidelines vary, in general they describe a range of medical conditions, with few guidelines on assessing cognitive function. As Gianutsos (13) comments, "the physician is thus placed in the difficult position of rendering an opinion both about complex cognitive functions.....as well as driving, a domain of performance in which they have had no training or experience other than as drivers themselves". We would urge physicians in this position to seek input from other rehabilitation specialists, particularly occupational and physical therapy, and, for those known or suspected of cognitive / behavioral impairment, neuropsychology. Increasing numbers of therapists are specializing in driver rehabilitation and in the United States there is a professional organization, the Association of Driver Educators for the Disabled, as well as Certified Driver Rehabilitation Specialist (CDRS) recognition(14,15). Also, in 1996, the New Zealand Association of Occupational Therapists inaugurated the first Special Interest Group in Driver & Passenger Assessment / Rehabilitation, with the aim of providing introductory and continuing education for occupational therapists in driver and passenger assessment.

Physical Skills. In the literature, no clear direction has been given in practical terms, on where to place emphasis on assessing people with musculoskeletal versus cognitive impairments. In the practical setting, clinical reasoning must be used to determine the appropriateness of encompassing the whole assessment battery for people with spinal injuries and musculoskeletal impairments only. Comments on musculoskeletal impairment in this chapter are drawn from Beatson’s extensive clinical experience in assessing and training drivers with physical disability.

There is limited information detailing which physical skills should be measured in relation to driving and which test is to be used. In 1995 Sprigle et al (16) "surveyed 403 evaluators throughout the United States" to clarify the "methods, equipment and criteria used when assessing an individual’s ability to drive". Although there was little agreement on the predictive ability of clinical evaluations, most people agreed that measurement of the following skills was important: "brake reaction time, steering reaction time, eye-hand coordination, brake force, steering force, gas force, range of motion, sensation, manual muscle strength, fine motor coordination, grip strength and pinch strength". However, not everyone used these assessments all the time. "Driving characteristics were determined most commonly by observing the task while in an evaluation vehicle, except brake reaction time..", which was measured by one of three different types of equipment. Overall, simple, inexpensive techniques were used for evaluation and the majority of evaluators were satisfied with their evaluation equipment. Sprigle et al conclude that "acceptable physical performance levels that could be used in driver assessment are typically unavailable to evaluators who measure driving characteristics". This is confirmed by the findings of Korner-Bitensky et al (17) who state that "the development and testing of a standard assessment that accurately predicts driving performance will be an enormous challenge for the profession".

Throughout the assessment the focus should be on the abilities which are relevant to the driving task from a functional perspective. In order to gauge which vehicle adaptations are most appropriate, the Occupational Therapist pays close attention to those actions which are difficult or impossible for the driver to perform. When considering the physical demands of driving a vehicle, in relation to any level of musculoskeletal impairment, it is useful to think of the driving compartment as a capsule, with all driving controls located on the frontal plane of the driver’s body. If the capsule were divided into four segments, one for each limb, it is then easy to assign the car controls in each the segments to each of the four limbs. This provides a convenient method of approaching functional assessment for the physical tasks involved in driving.

Upper limbs. Physical assessment includes functional assessment of upper limb range of movement, muscle strength and co-ordination. Using the capsule concept above, the right and left upper limbs need to be able to reach as high as the sun visor, as far laterally as the door and gear lever and as far in front as the dash board. These movements need to be rapid, accurate, able to carried out simultaneously with other tasks, and without visual direction. In order to steer, one or both limbs need to be able to cross the mid-line to describe a resisted arc, which is important to be able to complete several full, resisted rotations of the steering wheel during manoeuvres such as parking. Co-ordination and strength for steering is essential. But the exact amount of strength needed is dependent on the resistance from the steering wheel in the type of vehicle to be used. One older driver with Parkinson’s Disease appeared to have adequate strength for steering the assessment vehicle: a late model car with power steering. However, his car was old and without power steering. When driving his own car he struggled to steer the car smoothly around corners, due to his loss of muscle strength. Sharp turns at intersections were especially hazardous as, in the wide arc needed to control the vehicle, he narrowly missed parked vehicles, pedestrians and road engineering barriers.

If the driver is a "manual" wheelchair user, they will need sufficient arm strength and dexterity to dismantle and stow their wheelchair either inside or on top of the car. Trunk stability and upper limb strength is also essential to enable access to the driver’s seat.

Sufficient hand function and grip strength are needed to open the driver’s door and to operate driving controls which require a wide range of hand grips and dexterity. Drivers recovering from partial tetraplegia who have return of function to most of their body but who have a completely flaccid hand, experience many problems, for instance, opening the driver’s door. Unlocking can be achieved with an adapted key held between both wrists and the application of forearm movement. Alternatively a remote controlled device eliminates this effort. However, because of the flaccid hand and absence of any muscle tone to achieve hook grip, the ability to lever up the door catch to open the car is absent. This is an important barrier. If they cannot gain access to the car, they simply will not be driving.

A range of adaptations exist for gaining control over the steering wheel when only one upper limb is functional or when arm strength is adequate but hand function is absent. Illustrated in Figure 9, these include a steering wheel spinner knob, tri-pin and bi-pin. In New Zealand, a glove and pin attachment to the steering wheel results in appropriate contact with the steering wheel and a less bulky steering wheel modification. None of the devices described above will cross the center of the steering wheel. In any vehicle with a driver’s airbag, steering wheel adaptations which cross the center of the wheel are dangerous. On release of the airbag, the attachment will be forcibly removed and is likely to cause serious injury to the driver.

Lower limbs. Using the capsular driving compartment concept described above, there are few controls within the two segments occupied by the lower limbs. Namely, accelerator, brake and clutch pedals and sometimes a foot operated hand brake in the upper left segment of the lower limbs. Although relatively few in number, these controls are crucial to the safe operation of a motor vehicle and functional evaluation needs close attention.

Lower limb range of movement is necessary to achieve a relaxed sitting position with at least 90 degrees of hip and knee flexion. Drivers with knee arthrodesis will need close evaluation of the suitability of their own vehicle. When seated in the vehicle, their foot is forced up underneath the dashboard area. The driver’s seat will need to be pushed further back, to relieve the situation. But this can result in the upper limb controls being positioned out of reach. To relieve this situation, seating adaptations allow the affected leg to rest at a lower angle by scooping out a channel for the thigh.

Hip adduction and abduction movements are small but need to be performed with strength and accuracy. Knee extension is required for rapid, forceful braking in unexpected situations. Intact ankle plantar flexion and dorsiflexion are necessary to provide fine control over acceleration and braking. Because of the lack of ankle control, foot drop is not compatible with safe driving. Clients who have attempted to drive with foot drop report feeling puzzled that their car was constantly gathering speed. They did not relate this to their disability at the time.

Sensory feedback from prioprioceptors is essential to safety. Proprioceptor impairment can result in missing the brake when stopping or confusion between the position in space of the clutch, brake and accelerator. Impaired proprioception most commonly seen in a driver assessment case load, and which can be overlooked, are trauma to nerves or joint surfaces in the lower limbs, incomplete spinal injury, mild CVA, multiple sclerosis, referred pain and patchy sensation from a back injury, lower limb amputation with prosthesis, knee-ankle-foot orthoses. Reports of unsafe driving methods from drivers with these disabilities may include using their hands to apply pressure to their knee for varying amounts of acceleration; achieving braking by lifting the leg with their hand from the accelerator to the brake pedal; only being able to locate the pedals in daylight as they rely on visual cues for foot movement; using their left foot on all pedals instead of using their right; amputees driving with prostheses who report missing the foot pedals and accelerating instead of braking.

Lower limb muscle endurance is another important factor in determining whether it is advisable to use the lower limbs for driving. Where there is any question of intermittent function, such as in multiple sclerosis, it is always advisable to prescribe for those days or activities which result in the lowest level of function. There is often a desire from drivers with intermittent leg function to use their legs on good days and hand controls on their off days. Clinical experience from reports of a number of clients who have done so suggest that this can lead to involvement in crashes, probably because the person does not consistently use one driving technique.

Spinal Injury. The ability to raise the head to see the roadway ahead of the vehicle and maintain this position during driving is essential. Difficulty in head rotation will indicate the need for wide angled mirrors and retraining to use them correctly. People with rheumatoid arthritis, ankylosing spondylitis, reflex sympathetic dystrophy and cervical injuries such as severe whiplash are frequently affected. In order to bring their reduced vision to the client’s attention, it is useful to make a "map" of their blind spots, using cones or markers on the ground around them while they are seated. Translating this to the car can help convince people of the need to compensate for the gaps with the use of mirrors and open them to acceptance of retraining.

Following a stroke, spinal rotation can be markedly restricted, probably due to the imbalance of muscles in the trunk and spinal regions. This results in difficulty when turning to reverse the car and may require new learning with the use of mirrors in order to achieve safe manoeuvres. An estimation of sitting balance is important for people with weak trunk musculature because upper body stability is essential to maintain full control of the vehicle when cornering.

Visual skills. The importance of visual skills for driving cannot be over emphasized. For instance, Wylie (18) estimated that approximately 90% of the information processed while driving is taken in through the visual system. Nevertheless, some have raised questions, citing the importance of higher-order attentional processing (19) and instances where persons with significant visual impairments have been able to drive safely (20,21). In attempting to resolve this apparent contradiction, Gianutsos (22) cites the multiplicative effects of disabilities in combination, whereby substantial isolated disability can be managed, while in combination with another disability (not necessarily substantial) the resulting effect is magnified outside safe limits. So an individual might be able to compensate for isolated visual field impairment or an oculomotor problem, but not both in combination.

Strano (23) discusses the relationship of visual acuity to road engineering signage. In brief, when visual acuity is reduced, the time available to react to visual stimuli is equally reduced. Since visual fields are neither routinely nor periodically checked, and people with visual field losses may remain unaware (24), there are drivers with visual field loss. However, in most medical guidelines, homonymous hemianopia is deemed incompatible with safe driving. Quadrantanopia is a barrier to driving in at least one Australian state(11). Strano (23) discusses the difference in quadrants and their impact on driving. In her experience, upper quadrantanopia will have more serious implications on driving than lower quadrant defects. From an international perspective, relative seriousness of left or right quadrantanopia will depend on which side of the road the person will be driving in their home country. Visual fields are rarely seen to improve over time, even with retraining. Within optometry there are new optical interventions for visual field loss, which may also enable otherwise intact persons with field loss to drive safely (24-28). Strano also recommends that better compensatory field of vision will be obtained by "placing the [side rear-view] mirror well forward on the front fender" (23). Wide-angle mirrors can also be helpful, although the type and placement must be considered carefully so that confusion doesn’t substitute for increased information.

Low lighting conditions, tiredness, ill health and stress also negatively impact mild visual defects (23). Monocular vision produces a decrease in the available visual field and impaired depth perception (23). A wing mirror fitted to the side of the missing eye may be helpful. Careful evaluation and monitoring is essential under these circumstances.

Many DRSs use a stereoscopic vision testing device, such as is illustrated in Figure 10. In a few minutes these devices can be used to test acuity, binocular vision and stereopsis, color vision, and screen for responsivity in the horizontal peripheral field. Some include measures of contrast sensitivity, which has been found to correlate with at-fault crashes (29). Computerized protocols for measuring the functional visual field (24,30) or the Useful Field of View (19,31) have particular value as problems in these areas have obvious and demonstrated relationships to safe driving and are often poorly recognized by the individual with impairments.

Cognitive skills. Driving is such a complex skill, requiring efficient, integrated functioning on all levels under pressure of time that the relative importance of the skills involved are inherently difficult to define. Some facilities have used extensive neuropsychological testing (8,32) while others have reported success with specific computer assessment of a relatively small range of cognitive skills (9,13,33).

Cognitive skills which appear to be important for a positive outcome in driver assessment are visual discrimination, nonverbal reasoning, sequencing, spatial orientation, visual scanning, figure ground discrimination, visual tracking, right-left orientation (6). In 1992 Galski et al (8) found "visual perception...visual spatial analysis and synthesis, visuomotor coordination....planning, organising and executing test operations...scanning and attention, particularly selective sustained attention,...to be important in the prediction of actual performance." Galski et al (8) go on to warn that "many deficits in cognition did not adversely effect safe driving and were not equally important in predicting driving performance". Over the years, we have known, for example, people with profound recent memory impairment and aphasia who have sustained safe driving records. While these factors can serve as multipliers of other disabilities, they are not per se incompatible with safe driving. Carmella Strano was heard to observe at a conference that what counts is how the person deals with such problems, e. g., do they impulsively cross several lanes of traffic to make a turn for which they had forgotten to prepare.

Others may bring loss of contact with reality to the clinician’s attention, if not directly observed. While the implied lack of awareness has serious implications for driving safety, fortunately, there are usually others who recognize the need to intervene at this point to dissuade or prevent the person from driving. In these cases, it may not be productive to confront the individual, but rather to advise the family to assist with alternative mobility and to avoid the issue, if necessary, by removing or disabling the vehicle.

To the list of factors that need not be emphasized in the evaluation we should add variables, such as glare sensitivity, of which most drivers are aware and experience as barriers to driving safely.

A validated screening assessment battery, The Stroke Drivers Screening Assessment has been developed by Nouri and Lincoln, Nottingham, England (34). This assesses concentration, nonverbal reasoning and (British) road sign recognition. It takes approximately one hour to administer and is intended for use by a variety of health professionals to as an initial screening tool to identify those that are definitely unfit to drive a car. In the United States the Cognitive Behavioral Drivers Inventory (CBDI) (35) has been developed psychometrically (normed (36)and validated (37)), however, it lacks face validity (does not look to the client as if it has a relationship to driving) and its clinical utility is thereby reduced.

Complex, but non-interactive, driving simulators, such as the Doron illustrated in Figure 11, originally intended for learner driver education, do have the face validity, but have not been shown to predict the outcome of driving performance for people with disabilities (8,13). Simulation has much potential if it offers a dynamic interactive task that has a look and feel of driving (9,38-41). For instance, authors of two computer programs developed specifically for the detection of impairment in brain injured drivers in Christchurch, New Zealand (4) and New York, USA (13) report validity when computer results are compared to on road driving skills (9) and driver self-reported limitations (42). In using computerized assessment and on road evaluations with 261 aged drivers over 62 years, McKnight and Lange (43) report that "cognitive deficits evidenced the strongest association with unsafe (driving) performance".

The success of computer based programs is undoubtedly due to the unique ability of the computer to provide interactive, multiple information processing tasks, at speeds similar to that of the human brain. They take shorter times to administer and can rapidly analyse and present results. The need to assess global skills at rapid speeds in real time may account for why pen and paper assessment processes have difficulty in predicting the outcome of driving safety. Experienced DRSs, such as Amy Campbell of the Easter Seals Mobility Center (Meriden, CT), have dropped the paper and pencil procedures altogether, citing their lack of either face or empirical validity (personal communication).

Knowledge of road law. For people with brain impairment, additional tests examine knowledge of road law and decisionmaking when presented with a variety of traffic situations using road signs, slides or videotapes (44).

Client and family interviews. Important information regarding premorbid driving habits, past driving experience, current licence status and general personality traits can be gained from the client and a close family member or friend. Although it is subjective information, family and client interviews may add greater understanding of a wide range of lifestyle issues related to driving and place into context otherwise puzzling objective assessment findings.

It is important to remember that driving is not an end in itself, but merely a means to achieve a lifestyle goal as well as to carry out important life roles. Therefore if one can understand the person’s life roles in relation to driving, then final advice can be given in terms of which roles can be continued safely and which will need to be revised.

This assessment takes place in the practical setting: in a vehicle. For people with minimal physical disabilities, it is preferable to view their needs in relation to the car that they would normally be driving. For people with cognitive impairment only and no physical disability, this stage will be carried out rapidly and with minimal detail, as part of the preparation for an on road drive.

For most musculoskeletal driving assessments, a specially adapted vehicle with dual control brake and accelerator will be required. The aim of this stage of assessment is to identify those actions which the person can easily perform and to develop a detailed prescription for driving adaptations. As there is usually a large amount of detail during this phase, the use of a printed checklist is essential. A sample list is provided in Figure 12. One outcome of the static assessment may be that the current vehicle is clearly unsuited to their ergonomic needs and it should be replaced with another of more suitable design.

Mobility aids. If the goal is for fully independent function, depending on the level of musculoskeletal impairment, the type of mobility aids and method of stowage inside the vehicle will need careful consideration. For instance, because of its awkward shape, a lightweight fixed frame wheelchair, with wheels removed, is much more difficult to stow inside a car than a similar folding frame wheelchair. This is most noticeable in a four-doored vehicle, where the driver’s door pillar and the steering wheel restrict the space available. Drivers with limited mobility may use a wheelchair for longer journeys outdoors, e.g. for shopping and elbow crutches for short distances indoors. Therefore consideration will need to be given as to how the wheelchair is to be stowed, who will accomplish this and whether the car design allows for safe mobility when negotiating door openings.

Access. For some people, it is an accomplishment to achieve mobility as passengers. In this group are teenagers and adults with multiple handicaps, including physical and mental disabilities ranging from moderate to severe. It also includes former drivers who are no longer fit to do so. Whether in cars or vans, there are issues associated with method of access, stowage of mobility equipment, safety requirements and caregivers.

The height of the driver’s seat, width of the door opening, shape of the seat and leg room once inside may all impact on the functional ability and safety of the driver with a physical disability. The exact method of transfer into and out of the vehicle has a large impact on vehicle selection. If transfer from wheelchair to seat is not possible or contraindicated, then a van rather than a car will be required. If the driver is a permanent user of an electric wheelchair, a suitable vehicle must be selected which will allow adequate head clearance when entering and exiting the vehicle, as well as when sitting in the driver’s seat. As illustrated in Figure 13, floors of vans can be substantially lowered in order to achieve access. In addition to access to the van via a wheelchair hoist and specialist driving controls, appropriate wheelchair securing and safety belts will also be required. Assessment for people who intend to drive from their wheelchair is complex, involving specific decisions about items of costly equipment, which this chapter does not aim to explore. Detailed information should be sought from specialist driver assessors.

A variety of issues concerning access to the driver’s seat of a car become a problem depending on the type of impairment. For instance, people with back injuries experience difficulty due to restricted or painful spinal flexion and rotation. This is magnified in a sports car which is low to the ground. Older people with arthritic conditions in their spine also experience this difficulty. In this respect, we have an ergonomic mismatch. On the one hand, we have drivers who cannot reduce their body dimensions and have difficulty folding their body into a flexed position and on the other, car design which has evolved to leaving a small hole in the car frame for the driver to squeeze through at the door opening.

Primary driving controls. For convenience of clinical reasoning, New Zealand occupational therapists distinguish primary and secondary driving controls. Primary controls are those essential to the driving task, i. e., steering wheel, brake, accelerator, clutch, seat belt and turn signal. They are used most frequently in optimum daylight driving conditions and therefore carry high priority in determining whether driving is possible. During in-car assessment, it is important to attend to these first.

When a driver with a spinal injury is using hand controls, they often need extra space to rest their legs in order to avoid kinking the catheter tube and to maintain body balance. To enable this, the right sided accelerator pedal can be hinged out of the way. This is also an important safety precaution when lower limb extensor spasm is present, as a hinged accelerator ensures that unwanted acceleration is not applied during spasm. During driver training, a paraplegic client with a recurring problem of simultaneous extensor spasm in his right leg and flexor spasm in his left leg, which interfered with the steering wheel. Spasms seemed to be triggered by anxiety and were noted during complex traffic situations. He was advised by the assessor to see his physician for a review of anti-spasmodic medication. There was a reduction in spasm sufficient to allow him to pass the practical driver’s test without anxiety-produced lower limb spasm.

In the absence of reliable function in the right leg, when using an automatic vehicle, a left sided accelerator pedal can be added. Retraining is important in order that the driver can use the same movement under all driving circumstances. In order that other people can also use the vehicle, it is standard practice to hinge the right accelerator so that it is out of the way but available for normal use. Reports from clients of minor scrapes in driveways and garages etc caused by friends and family who attempt to drive the modified car illustrate the importance of ensuring the client is well educated in safety precautions.

Drivers with short stature may require a range of driving adaptations including raising the height of the foot pedals. At the same time, it is necessary to reduce the length of the seat base to ensure that knee flexion is possible. A raised false floor gives the driver greater body stability when driving. Kleinberger and Summers (45) reported that severe or fatal air bag induced injuries were more likely to occur in women drivers with short stature (1.60m), who do not wear a safety belt and who sit closer than 10 inches to the steering wheel. Therefore it is imperative that satisfactory methods are found to enable the seatbelt to be worn and that the airbag mechanism be turned off in circumstances when they cannot be safely deployed.

Secondary driving controls. The remaining in-car controls represent the actions taken intermittently when driving, many of which can be adapted for easy use or operated by remote control. Frequently requested remote control functions include headlight dimmer switch, windshield wipers and adapting windows to electric operation. Special attention will need to be paid to drivers with marked hand impairment, such as rheumatoid arthritis, tetraplegia, severe hand trauma and upper limb amputations. In considering this list, roles and lifestyle of the driver become important. For instance, daily use of fee-paying parking buildings mean that it is essential to be able to operate the driver’s window quickly; the driver’s desire for music while driving will influence what type of switches are appropriate on the radio cassette or CD player.

Issues. Many debates has arisen over the reliability and validity of using actual on road driving for behavioral and cognitive assessment; nevertheless, it is an essential component of driver rehabilitation. Indeed a standard of care is evolving (46) to the effect that no one should be advanced to resumption of driving without an on-road assessment. This is not to say that everyone should be taken out on the road. Nor does it mean that performance on the road test overrides the outcome of the in-clinic assessment. Realistically, the aim is to determine whether the person with a disability is likely to be able to cope with driving in their locality, mostly on familiar routes, in order to pursue their goals and life roles. Whether a driver is likely to drive more than this or for extended periods outside familiar areas will have been discovered during the client and family interview. By this stage of assessment, hopefully anyone clearly unsuited for driving has been screened out of the program.

When assessing drivers with musculoskeletal impairment only, the on road drive fulfils a slightly different role. Having established what range of adaptive driving equipment is likely to be suitable, the next step is to confirm in practice that the driver is actually able to use them in safety. There is a substantial learning curve when changing any type of driving technique, whether complex or simple. Sufficient time must be allowed for the driver to determine that they have full control over the vehicle before entering traffic flows. Essentially, they have become a learner driver again and will require competent instruction in order to feel safe in the new environment. The assessor needs to be aware of the emotional dynamics happening at this stage and to stop and diffuse problems at any sign of unease. Drivers with low self esteem may not feel confident in their abilities to drive; if injured in a motor vehicle crash their first time back in the driver’s seat may have heavy emotional significance; or the person may simply have difficulty coordinating their limbs in a new way to achieve vehicle control. The use of an adapted vehicle with dual controls is essential to safety when assessing or retraining drivers who are new to driving with a disability.

Because occupational therapists (with their deep commitment to function) and most clients are impressed by the face validity of the on-road assessment, it is perhaps in order to introduce some considerations to modulate this enthusiasm, and to inspire improvements. First, "the" road test means many things to many people. The tests actually used, therefore, have no norms, nor established reliability and validity. In other words, the road test given to most clients does not even begin to meet the most basic standards for psychological tests and measurements (47). Interestingly enough, there have been attempts to develop a standardized road test (48,49) and substantial effort went into establishing its reliability. This "Michigan" test - unknown to most therapists in the United States - was adopted and adapted in New Zealand for evaluating advanced learner drivers (50). Implementation in each locality calls for extensive study of the level of skills accepted by the Police for safe driving, establishment of a route containing a wide variety of driving conditions and documentation during and after the 40 minute on-road drive. The documentation for each locale is several centimeters thick (about the size of a large urban telephone directory). Examiners receive two weeks of specialized training. Needless to say, the practical hurdles are significant, especially for community-based services. There is a major need to develop a practical on-road assessment protocol which can be implemented in different locations with norms and acceptable levels of measurement reliability.

Then again, it would still be necessary to demonstrate that the test is a valid index of the individual’s ability to drive safely. The appearance of validity, while clinically essential, is not sufficient. The vexing issue faced by all attempts to proving the validity of a given measure of driving, whether off-road or on-road, is the lack of an independent criterion. In the case of older drivers, free of overt neurological diagnoses, but with possible age-associated cognitive decline, one can attempt to use recent driving record - but even that is influenced by reporting and recording variables. A fundamental problem for measurement (but not for safety) is the fact that most older drivers limit themselves when their capabilities decline (42). Statistically, the validity coefficients shrink when poorly performing subjects maintain good driving records because they drive very little.

Even if such a protocol were available, it would constitute a limited sample of performance while being watched, which could cause the individual to be nervous, or, at least, on their best behavior. Indeed, one insightful therapist (Steve Mitchell, ADED Northeast meetings, October 1994) looks for just this capability - does the client recognize that the testing situation calls for one’s "best behavior?"

The face validity of the road test is a significant plus, but even if the psychometric limitations could be resolved, it would not be a complete assessment, its functionality notwithstanding. With off-road procedures aimed at assessing cognitive skills only, it is possible to simulate the types of crisis situations and to measure performance in precise quantitative ways. The most demanding aspects of driving can be safely condensed into a practical time frame. The more the off-road procedure simulates driving, i.e., has face validity, the more clinically effective it will be.

Many therapists have developed expertise to conduct on road evaluations, through choosing quiet roads to minimize risk and then graduating the client through increasingly busier areas. Some also become qualified driving instructors. Another approach recommended by trainers of Occupational Therapists as Driver Assessors in Australia and now accepted as standard practice, is for the therapist to collaborate with an experienced local driving school instructor with an interest in working with drivers with disabilities. The therapist observes and records findings from the back seat, free of the responsibility to assure that the vehicle is operated safely. Under some circumstances, after observing the driving instructor, the therapist may feel comfortable enough to rely on the instructor’s report. In uncomplicated cases where the individual has done very well on the in-clinic assessments, it may be sufficient to have a report from a local driving instructor.

If the coordinating therapist is not participating in the on-road evaluation, it is important to structure the process in such a way that the final recommendations remain in his or her hands so that all the findings and medical information are taken into account. While the on-road assessment may be the final step in the process, the results should not be the last word. For instance, off road screening can show marked deficits in some areas of cognition, which are not observed on the road. At the least, the driver should be counselled by the therapist following the on road drive and be made aware of what factors may constitute risky driving situations.

Finally, we must acknowledge that the state of the art in road testing is the "sweat index" - a global integration of the examiner’s objective observations and subjective comfort level, signalled by their autonomic nervous system.

Routes. A review of published clinical practice (33,51), shows that occupational therapists, working with driving instructors, progress the client through a series of routes of increasing complexity. Fox et al (51) in Sydney, Australia uses four " standard assessment driving routes of increasing complexity...each requiring about 50 minutes to complete. The least complex drive is conducted within the Centre grounds, and the most complex in heavy density traffic incorporating freeway driving, road map navigation and multistorey car park manoeuvres where appropriate".

During this time, observations are recorded on a printed sheet which lists predetermined risk factors. van Zomeren et al (7) have compiled an extensive list of commonly found driving faults. In New Zealand, driving instructors now use an Advanced Assessment and Training Report (52) as part of a three tiered licensing system. Occupational therapists in New Zealand are also using this same assessment approach. "The purpose of the assessment is to require drivers to demonstrate that they are skilled in the areas of Hazard Identification, Judgement, Manipulating Controls and Observing Traffic Regulations." The assessment is to last 40 minutes. The route "will, where practicable include suburban highway and motorway [freeway] conditions with at least 20 minutes of the time spent in busy city / town situations. (Medium to heavy traffic conditions should be sought)" (52).

An informal review of on-road assessment protocols in use in many driver rehabilitation programs indicates that the emphasis is on the operational level, i.e., mechanical skills. As suggested earlier, consideration should be given to incorporating the tactical level into the assessment. While examiner preparation and standardization call for a fixed route, this very fact removes the opportunity for tactical decisionmaking regarding the route, unless the assessor specifically allows for it, e.g., by asking on return to "base" at the end of the drive "can you find your way back now?"

COMMUNITY INTEGRATION

From the functional perspective of occupational therapy, besides formal assessment, it is helpful to examine the reality of the client’s actual situation more fully.

Terrain. Knowledge of the area in which the person with a disability intends to drive is an important aspect. Understanding the area and risks inherent for a particular disability type will help to bring a practical focus for the client and family. Demonstrating a realistic understanding of their situation is likely to aid adherence to any recommendations made.

If the area is hilly with winding roads, then methods to maintain upper body balance when cornering will be essential for people with weak trunk stabilising muscles. Evaluation or prescription of the design of the driver’s seat will also be necessary.

If a client with a back complaint is likely to be driving over rough ground, over poorly maintained or unsealed roads in rural areas, or over tram and railway tracks in the city, then no intervention is likely to be successful as it is the environment which is compounding the disability. If the vehicle is a light van or truck and the driver’s seat is positioned over the front axle, the effect is to amplify every jolt on the road. In this instance, the vehicle and the terrain may become the prime focus of advice to the client. For instance, in the short term, the goal may be to avoid driving or to find alternative routes, and in the medium to long term to change their vehicle as well as their place of residence.

To illustrate, a client who had had recent spinal surgery had correctly identified the poorly maintained roads near his country home as a barrier to his return to work. However, he had not realized the importance of changing his vehicle from a four wheel drive with hard suspension to that of a sedan with highly absorbent suspension. He drove both vehicles over the same route. Whereas the four-wheel drive seemed to magnify every small bump on the road, the sedan simply absorbed them.

For someone with cognitive or psychiatric impairment, who is prone to concentration lapses, the monotony of driving on long, straight roads, such as on the freeway or in the Australian outback, is likely to contribute to a crash.

Climate. Weather factors specific to the driver’s locality also needs consideration. People with impaired contrast sensitivity may be unsafe to drive in mountainous areas where there is poor illumination during fog, drizzle or snow. People with poor glare recovery may be also be affected by oncoming headlights at night as well as environmental factors. For instance during summer months in Auckland, New Zealand, commuters travelling west into the sun are at high risk of accidents due to what has become known as "sunstrike", i.e., being dazzled by glare from the sun.

Galski et al (8) found that "behavioral measures...showed significant correlations to driving performance in traffic....it indicated that drivers who manifested specific [safety compromising] behaviors achieved poor outcomes in traffic". In his book, Traffic Safety and the Driver, Evans (1) devotes an entire chapter to driver behavior. Driver behavior is not what the driver can do but what the driver in fact does do. It is initially surprising to discover that in a study of the safety of racing car drivers and closely matched comparison drivers that "on a per year basis, the racing drivers had substantially more crashes and more violations, especially speeding violations". Evans provides a great deal of evidence that "we drive as we live". Evans continues: "If his personal life is marked by caution, tolerance, foresight and consideration for others, then he would drive in the same way. If his personal life is devoid of these desirable characteristics then his driving will be characterized by aggressiveness.."(1). Therefore when assessing drivers who lack insight, such as those with frontal lobe impairment and unresolved psychiatric conditions (the impulsiveness of hypermania, those who respond to delusional thoughts or voices, those with unstable mood levels), assessment battery results must be interpreted with caution. During off road assessment, additional emphasis will therefore need to be placed on safety compromising behaviors.

Professional experience and even some data (53) reveal that many practitioners are unaware of their responsibilities to their patients regarding driving. Some useful articles are available on this subject (54,55). Gianutsos formulated a statement on "What happens to your New York State driver’s license after a brain injury?" addressed to patients. She had the statement reviewed for accuracy by the New York State Department of Motor Vehicles. It is included as Appendix 1 and readers are encouraged to adapt it to their own jurisdictions. They may adapt and distribute it if they acknowledge the source and send her a copy.

Some rehabilitationists adopt a "don’t ask don’t tell" posture regarding driving. It is safe to assume that all patients who were drivers are would-be drivers, no matter how severe their disabilities. Apprehensive about a negative decision, if there are no significant physical disabilities, they may not seek advice on the issue. However, as Antrim and Engum (56) emphasize, there is no legal safety in rehabilitation facilities avoiding the issue of driving. Nor is ignorance of the applicable law an excuse.

In most jurisdictions there is an agency which controls licensure, e.g., the state Departments of Motor Vehicles in the United States, the Ministry of Transport in New Zealand, and the Roads and Traffic Authority in Australia. In some cases these agencies are national and in others state or provincial. There is a legal code which governs this agency, as well as statutes which detail its practices. These rules include what medical and visual standards must be met for initial licensure and renewals. The most significant issue for rehabilitation professionals is whether and how the existence of a disability comes to the attention of the licensing agency. The range of possibilities includes mandatory reporting by health care providers, optional reporting with immunity (against claims of violation of confidentiality), reporting by the individual prior to resumption of driving, and reporting upon renewal of licensure. In the United States 6 to 8 of the states have some form of mandatory reporting. British Columbia has an interesting variation with what could be called "mandatory reporting to the individual" (that is, a mandate to raise the issue and make recommendations) followed by reporting to the licensing agency in those instances where non-compliance comes to the provider’s attention. Because there is such a wide range of possibilities, it is essential for practitioners to find out what the law is from their local licensing agency.

Prior to initiating the driving advisement process, it is important to have an explicit statement about what will be offered, individual responsibilities and to whom the resulting information will be sent. Gianutsos uses a "Memo of Understanding" for this purpose, offered as Appendix 2, which can be adapted and used to meet individual needs. It is recommended that the patient receive a written copy of the resulting report and recommendations. We have received a legal opinion that it is not sufficient to make an entry in the patient’s medical record about recommendations given orally.

Helping our patients return to safe independent mobility is part of our clinical mission. While the legal aspects may be daunting, we must give our patients access to every resource and clinical insight we can marshal. If the outcome is not favorable, they need to know why: they may not be entitled to a license, but they are entitled to an explanation. Further, we need to offer constructive, and often creative, suggestions regarding mobility alternatives.

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P = physical disability, requiring a musculoskeletal approach

C = brain insult, requiring a cognitive approach

P and C = requires both musculoskeletal and cognitive approaches

Figure Captions

Fig. 1 "A" with incomplete tetraplegia uses elbow crutches for short distances and a fixed frame wheelchair for longer journeys.

Fig. 2 "A" getting into the driver’s seat. Weak muscles combined with heavy limbs makes this a slow process.

Fig. 3 "A" demonstrates hand controls and steering wheel spinner. Even in the most ideal vehicle, space for equipment was limited.

Fig. 4 Foot positioning: Wearing an ankle foot orthosis in a restricted space and weak thigh muscles make foot positioning difficult. This photo shows the right accelerator pedal hinged out of the way for safety.

Fig. 5 Drivers seat was substantially repositioned to the rear to enable "A" to sit in it. A seat belt extension, which can be seen between both seats, enables "A" to locate and engage the seatbelt.

Fig. 6 "B" use of the train was an important component of his driver rehabilitation and it continues to be part of his mobility plan.

Fig. 7 Elemental Driving Simulator (EDS) standard model. An IBM PC-compatible computer (not shown) controls a dynamic display of a schematic roadway and peripheral stimuli. The patient controls the lateral position of the "car" using the steering wheel and uses the turn signal to make responses. For hemiparetics, the foot pedals are used for responding.

Fig. 8 Oversized center mounted rearview mirror.

Fig. 9 Adaptive steering wheel controls allow for a range of upper limb abilities; frequently used with tetraplegic drivers. (top panel) Steering wheel spinner in the right hand gives full control over the wheel, even on sharp turns. Hand controls operate brake and accelerator pedals. (lower left) A bi-pin is used for those with active wrist extension. (lower right) Tri-pin firmly supports the wrist and stabilizes the hand of drivers with tetraplegia. Both bi-pin and tri-pins attach to the steering wheel through a pin which fits the steering wheel clamp.

Fig. 10 Stereoscopic vision screening testing device at the Easter Seals Mobility Center, Meriden, CT. This model is made by Stereoptical and other models are produced by Titmus and Keystone.

Fig. 11 Doron Driver Analyzer at the Easter Seals Mobility Center. When performing the simulation, the patient would be viewing a movie video projected on a large screen directly ahead. The console is physically realistic; however, the task is not interactive, i.e., nothing that the patient does changes the display.

Fig. 12 Form for static, in-car assessment.

Fig. 13 Adapted van at the Mobility Center: The floor has been lowered by 10 inches on this 1990 ?? Dodge van. A side mounted hoist installed in a van allows self loading and driving from a wheelchair. In the top panel, the door opens by remote controlled switch. (middle) Hoist lowers automatically. (bottom) Hoist in wheelchair loading / unloading position.