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April 01, 2016

Evaluating the Capacity to Drive

Erica F. Wood

(The pdf for the issue in which this article appears is available for download: Vol. 37, Issue 4.)


In the classic 1985 science fiction fantasy movie Cocoon, a group of residents from a retirement home are rejuvenated as they swim in a fountain of youth pool charged with special life force by aliens. As they feel their youthful energy and clear vision returning, a memorable scene shows one of the retirees gleefully ripping off the cover on his neglected car, getting behind the wheel, and zooming off.

That is likely the wish of many older adults who have given up the keys. But, short of alien intervention, to drive they must have the requisite “capacity.” What is this illusive concept of “capacity to drive”? What are its components and how is it assessed?

The Commission on Law and Aging has been looking at issues of capacity for well over decade, in partnership with the American Psychological Association. Together, the ABA Commission and the APA have produced three widely recognized handbooks on capacity assessment—one for lawyers, one for judges, and one for psychologists (see our website at Each sets out steps for evaluating ability to engage in a range of decision-making actions and legal transactions.

But evaluating capacity to drive is of course different from evaluating capacity to make decisions or execute legal transactions. First, driving involves a mix of mental, physical, and sensory abilities. Second, driving has serious risk not only for oneself but also for others as well. And third, the determination of capacity to drive initially rests not with a judge but with the commissioner of the state department of motor vehicles—although judges may well be involved in decisions about drivers licenses, as described in the “View from the Bench” by Judge Lyle. While state laws vary, the Uniform Vehicle Code provides that a license may be denied if the state commissioner finds that a person “by reason of physical or mental disability would not be able to operate a motor vehicle with safety upon the highways” (National Committee on Uniform Traffic Laws and Ordinances).

The ABA-APA handbook for psychologists sets out a general capacity evaluation framework with nine steps. A chapter on assessing specific capacities seeks to apply the steps to several particular abilities including driving—under the overall concept that “capacity” is not global but task specific.

Drawing from the handbook, as well as the informative articles in ... [the Fall/Winter 2016 issue of Experience magazine], the first element in the ABA-APA framework is the legal element. While driving is a privilege, in our mobile society it is often seen as a right—and it rests with the state department of motor vehicles to deny it in order to ensure the safety of the driver and others on the road. Typically, clinical judgments about capacity in any specific area are along a continuum, whereas legal judgments are more binary—you either have it or you don’t, for the action at hand. Thus, a clinician may evaluate an older driver and report a range of cognitive, sensory, and physical results, and the state agency will use this evidence to make a final yes–no legal determination.

The second assessment element is the functional component, which really comes to the forefront in the driving context. Before making a functional assessment, it is important to look for supports and accommodations that might enhance ability. Never ask if the person “has capacity,” but rather ask “does the person have capacity with support.” In the driving context, this might mean a change of eyeglasses, a higher seat or pillow, a revolving seat, or pedal modifications. With such supports, a functional assessment will test for visual acuity; flexibility to look behind and check blind spots on the road; and strength for control of the steering wheel, brakes, accelerator, and clutch. An assessment also will test the driver’s knowledge about driving rules and what to do in emergency or unexpected situations.

The diagnosis is the third assessment element. A range of medical conditions might affect the ability to drive—such as, for example, sensory problems, muscular or skeletal problems, possibility of strokes, or psychiatric disorders. Dementia can affect memory, spatial abilities, and judgment needed to drive. However, it is important first to assess for any temporary or reversible conditions, or problems that could be safely addressed with medication or other strategies. Also, note that neither age nor medical condition alone is a sound basis for denying a driver’s license, as explained in the “View from the Bench”—nor for evaluating ability to perform any other specific task at hand.

An assessment also will look at cognitive ability—that is, the way the brain receives, processes, stores and accesses information. As the ABA-APA handbook points out, this can involve numerous tests bearing on driving performance such as attention and processing speed, changes in the visual field, memory, decline in peripheral vision and decreased ability to perform more than one task at a time. Cognitive abilities can be affected by sleep disturbances, medications and substance abuse—including prescription drugs, alcohol and pain, sleep or anxiety medication—and it is critical to take these reversible conditions into account in assessing cognition.

Psychiatric or emotional factors also contribute to an evaluation of driving ability. For instance, delusions and hallucinations can distort driving behavior. Depression can cause fatigue and lead to poor driving decisions. For these reasons, a mental health assessment can be an essential component in examining the ability to drive.

Any good capacity assessment also must take into account the person’s values. Certainly society and most older drivers place a high priority on driving for independence, self-esteem and access to needed medical, social and recreational services. Some studies have shown that adults who stop driving may experience depression and lack of participation in meaningful activities. As described by the Rosenblatt article in this issue, as well as the one by Madeira & Rosenblatt, involving the older adult in planning for good transportation options through public transit—if it exists in the community—or through private arrangements, can make a big difference. For example, in a growing number of communities, the “village” movement may be a good resource. Grassroots neighborhood villages help people age in their own homes by providing supports, services, and a community network, and may offer volunteer transportation services.

The next step in the ABA-APA capacity assessment is an evaluation of risks. Clearly there are risks on both sides of stopping driving. Statistics show that the risk for driving injury and fatality increases with age, and stories of older drivers injuring not only themselves but innocent bystanders are not uncommon. On the other hand, loss of the driving privilege can lead to isolation, depression, and decreased ability to get to doctors and meet health needs. The benefits and risks need to be thoroughly examined from both sides.

As stated earlier, examining steps to enhance driving capacity is an integral part of the driving assessment. These might include modifications to the car, review of treatable or reversible conditions, and taking driver’s education courses such as the AARP Driver Safety Program.

The final step in the ABA-APA assessment model is the clinical judgment required to integrate all of the evidence from the previous steps on supports, conditions, risks, abilities and limitations. The clinician may recommend that the person needs to stop driving, that the person can safely operate a vehicle on the road, that more testing is needed, or perhaps that the person needs accommodations or should prepare for a transition to reduce or stop driving within the near future. The ABA-APA guide applies the assessment model to selected case examples concerning driving, such as this one:

Mr. B was a 68-year old man diagnosed with traumatic brain injury with improving cognitive status, high blood pressure, and dislocation of the left shoulder. He had a number of neuro-behavioral tests in which he rated average for most aspects, with borderline anxiety and depression. His driving evaluation was conducted by an occupational therapist, who found he had good control of the car, good safety habits, and good ability to solve problems in driving scenarios, as well as adequate visual processing. The evaluator tested his peripheral vision and visual perception. In assessing his physical ability, the evaluator noted a limited range of motion in the left shoulder, and urged a program of physical therapy. The evaluator recommended a referral to the department of motor vehicles for a formal road test, and shortly thereafter, the driver successfully passed the test.

In the coming years, capacity to drive may become somewhat passé with the advent of driverless cars, but until then, there will be a need for a sound conceptual framework to evaluate a driver’s ability to safely operate a car on the road. ■

Erica F. Wood

Erica F. Wood is assistant director of the ABA Commission on Law and Aging. She has worked with the Commission since 1980 on issues concerning adult guardianship, legal services delivery, dispute resolution, health and long-term care, and access to courts.

Published in Experience, Volume 26, Number 1, Fall/Winter 2016. © 2016 by the American Bar Association. Reproduced with permission. All rights reserved. This information or any portion thereof may not be copied or disseminated in any form or by any means or stored in an electronic database or retrieval system without the express written consent of the American Bar Association.