Assessing Fitness to Drive

In this section

6.1.1. Relevance to the driving task

6.1.2. General assessment and management guidelines

6.1.3. Medical standards for licensing

Refer also to Part A section 2.2.7. Older drivers and age-related changes and section 2.2.8. Multiple medical conditions.

Dementia is a syndrome due to a disease of the brain, usually of a chronic or progressive nature, in which there is disturbance of one or more cognitive functions beyond what might be expected from normal ageing. It can affect memory, thinking, orientation, comprehension, calculation, learning capacity, language and judgement. Consciousness is not clouded. The impairments are commonly accompanied, and occasionally preceded, by deterioration in emotional control, social behaviour or motivation.

Disease pathology without cognitive impairment can be seen in preclinical dementia, while a slight but noticeable decline in some cognitive functions may indicate mild cognitive impairment (MCI) or prodromal dementia. Alzheimer’s disease is the most common form of dementia and may contribute to 60–70 per cent of cases. Other major forms include vascular dementia, dementia with Lewy bodies, and a group of diseases that contribute to frontotemporal dementia.

The estimated proportion of the general population aged 60 or older with dementia at a given time is between 5 and 8 per cent. Although age is the strongest known risk factor for dementia, it is not an inevitable consequence of ageing. Further, dementia does not exclusively affect older people – young-onset dementia (defined as the onset of symptoms before the age of 65 years) accounts for up to 9 per cent of cases.

Effects of dementia on driving¹

Dementia is characterised by significant loss of cognitive abilities such as memory capacity, psychomotor abilities, attention, visuospatial functions, insight and executive functions.

Dementia may affect driving ability in several ways including:

• errors with navigation, including forgetting routes and getting lost in familiar surroundings
• limited concentration or ‘gaps’ in attention, such as failing to see or respond to ‘stop’ signs
• errors in judgement, including misjudging the distance between cars and misjudging the speed of other cars
• confusion when making choices – for example, difficulty choosing between the accelerator or brake pedals in stressful situations
• poor decision making or problem solving, including failure to give way appropriately at intersections and inappropriate stopping in traffic
• poor insight and denial of deficits
• *slowed reaction time, including failure to respond in a timely fashion to instructions from passengers
• *poor hand–eye coordination.

Other causes of fluctuating cognitive impairment or delirium, such as hepatic, renal or respiratory failure, do not usually have an impact on licence status and may be managed in the short term according to general principles (refer to Part A section 2. Assessing fitness to drive – general guidance).

Evidence of crash risk^2,3

Dementia syndrome and symptoms are associated with a moderately high risk of collision compared with matched controls. However, the evidence does not suggest that all people with dementia symptoms should have their licences revoked or restricted. Throughout all stages of their condition, drivers require regular monitoring regarding progression of the disease. While for some drivers the crash risk is minimised because they choose, or are persuaded by their family, to voluntarily cease driving, others with significant cognitive decline and limited insight may require careful management and support in this regard, as discussed below.

Preclinical dementia⁴

Preclinical dementia is increasingly being identified using modern diagnostic techniques. The dementia-related pathology is diagnosed in advance of the clinical manifestations of dementia itself, including symptoms that impair driving (e.g. preclinical Alzheimer’s disease). A person diagnosed in this manner, who has no clinically significant symptoms of dementia, can be considered fit to drive. Health professional review may be appropriate to monitor disease progression and development of dementia symptoms.

Mild cognitive impairment^5,6,7

MCI, which incorporates the prodromal stage of dementia, causes a slight but measurable decline in cognitive abilities. The cognitive changes are noticeable to the person and to family members and friends but generally do not affect the person’s ability to carry out everyday activities. Driving studies examining the effects of MCI found limited evidence of increased driving error rates, concluding that MCI does not significantly impair driving. Where there is impairment across multiple cognitive domains such as visuospatial, attention and executive functions, it may be appropriate to consider the driver’s fitness to drive and perform an assessment as outlined below.

Dementia assessment⁸

Due to the progressive and irreversible nature of the condition, people with a diagnosis of dementia will eventually be a risk to themselves and others when driving. The level of impairment varies widely – each person will experience a different pattern and timing of impairment as their condition progresses, and some people may not need to stop driving immediately. Individual assessment and regular review are therefore important, although it is difficult to predict the point at which a person will no longer be safe to drive.

A combination of medical assessment (including specialist assessment as required) and off-road and on-road practical assessments appears to give the best indication of driving ability. For further information about practical driver assessments refer to Part A section 2.3.1. Practical driver assessments.

The following points may assist in assessing a person:

• Driving history. Have they been involved in any driving incidents? Have they been referred for assessment by the police or a driver licensing authority?
• Vision. Can they see things coming straight at them or from the sides? (refer to section 10. Vision and eye disorders)
• Hearing. Can they hear the sound of approaching cars, car horns and sirens?
• Reaction time. Can they turn, stop or speed up their car quickly?
• Problem solving. Do they become upset and confused when more than one thing happens at the same time?
• Coordination. Have they become clumsy and started to walk differently because their coordination is affected?
• Praxis. Do they have difficulty using their hands and feet when asked to follow motor instructions?
• Alertness and perception. Are they aware and understand what is happening around them? Do they experience hallucinations or delusions?
• Insight. Are they aware of the effects of their dementia? Is there denial?
• Other aspects of driving performance.
  • Can they tell the difference between left and right?
  • Do they become anxious or confused on familiar routes?
  • Can they comprehend road signs?
  • Can they respond to verbal instructions?
  • Do they understand the difference between ‘stop’ and ‘go’ lights?
  • Are they able to stay in the correct lane?
  • Can they read a road map and follow detour routes?
  • Has their mood changed when driving? (Some previously calm drivers may become anxious, panicked, angry or aggressive.)
  • Are they confident when driving?

Because of the lack of insight and variable memory abilities associated with most dementia syndromes, the person may minimise or deny any difficulties with driving. Relatives may be a useful source of information regarding overall coping and driving skills. They may comment about the occurrence of minor crashes, or whether they are happy to be driven by the person with dementia. Referral for a practical driving assessment may be warranted where sufficient concern or uncertainty remains regarding the degree of impact of the cognitive impairments (refer to Part A section 2.3.1. Practical driver assessments).

Transition from driving

Licence restrictions, such as limitation of driving within a certain distance from a driver’s home, may be considered by the driver licensing authority (refer to section 6.1.3. Medical standards for licensing). Community mobility assessment and planning with reference to cessation of driving may include family support, accessing local public transport or using community buses, and providing information about taxi and other community transport services available for people with disabilities. A number of resources are available to support the transition. Specific information resources are available from Dementia Australia for drivers with dementia and their family/carers.

Failure to comply with advice or licence restriction

People may continue to drive despite being advised they are unsafe, and despite their licence being restricted or revoked. This may be because of denial, memory loss or loss of insight. Discussions with the person’s family/carers may be helpful, and alternative transportation can be explored. Where the person is judged to be an imminent threat to safety, all states and territories provide indemnity for health professionals and other members of the public who notify the driver licensing authority of at-risk drivers; the driver licensing authority will then take the necessary steps.

Consumer Resources

Alzheimer’s Australia has a range of resources to help people with dementia and their families, as well as resources to guide health professionals.

Some Driver Licensing Authorities also produce resources that align with their jurisdictional requirements and available supports.

Requirements for unconditional and conditional licences are outlined in the following table. Health professionals should familiarise themselves with the information in this chapter and the tabulated standards before assessing a person’s fitness to drive.

Due to the progressive nature of dementia and the need for frequent review, a person diagnosed with this condition may not hold an unconditional licence for either a private or commercial vehicle. Private vehicle drivers may be considered for a conditional licence subject to medical opinion and practical assessment as required. The practical assessment is generally appropriate for borderline cases where the impact on driving is unclear. Commercial vehicle drivers require specialist assessment including a practical driver assessment (refer to Part A section 2.3.1. Practical driver assessments).

One option available to maintain a driver’s independence despite a reduction in capacity is to recommend that an area restriction be placed on the licence. This effectively limits where the person can drive and is most expressed as a kilometre radius restriction based on their home address. Drivers should be capable of managing usual driving demands (e.g. negotiating intersections, giving way to pedestrians) as required in their local area. These licence conditions are only suitable for drivers who can reasonably be expected to understand and remember the limits as well as reliably compensate for any functional declines.

The ability to respond appropriately and in a timely manner to unexpected occurrences such as roadworks or detours that require problem solving should also be considered. People lacking insight or with significant visual, memory or cognitive-perceptual impairments are therefore usually not suitable candidates for a radius restriction. When advising such a restriction it is also important to remember the following:

• A driver may not always appreciate the meaning or extent of a specified number of kilometres from home.
• Potential hazards such as pedestrians, intersections, roadworks, bad weather and detours can still exist in familiar streets close to home and can be a source of confusion.
• A driver licence is a legal document that demonstrates that a driver has satisfied the driver licensing authority that they are fit to use the road system as it exists – this means they must be competent to deal with unexpected and hazardous situations, even when limited to driving close to home.
• Restrictions to specified routes are not practicable and should not be advised.

Drivers with a diagnosis of dementia will generally not meet the commercial standards. In some situations a conditional licence may be considered by the driver licensing authority subject to careful assessment by an appropriate specialist. Commercial vehicle drivers must also be subject to a practical driver assessment (refer to Part A section 2.3.1. Practical driver assessments).

References and further reading

1. Rapoport, M. J. et al. An international approach to enhancing a national guideline on driving and dementia. Current Psychiatry Reports vol. 20 (2018).
2. Chee, J. N. et al. Update on the risk of motor vehicle collision or driving impairment with dementia: a collaborative international systematic review and meta-analysis. American Journal of Geriatric Psychiatry vol. 25 1376–1390 (2017).
3. Charlton, J.L., Di Stefano, M., Dow, J., Rapoport, M.J., O’Neill, D., Odell, M., Darzins, P., & Koppel, S. Influence of chronic Illness on crash involvement of motor vehicle drivers: 3rd edition. Monash University Accident Research Centre Reports 353. Melbourne, Australia: Monash University Accident Research Centre. (2021)
4. Dubois, B. et al. Preclinical Alzheimer’s disease: Definition, natural history, and diagnostic criteria. Alzheimer’s and Dementia vol. 12 292–323 (2016).
5. Hird, M. A. et al. Investigating simulated driving errors in amnestic single- and multiple-domain mild cognitive impairment. Journal of Alzheimer’s Disease 56, 447– 452 (2017).
6. Eramudugolla, R., Huque, M. H., Wood, J. & Anstey, K. J. On-road behavior in older drivers with mild cognitive impairment. Journal of the American Medical Directors Association 22, 399-405.e1 (2020).
7. Anstey, K. J. et al. Assessment of driving safety in older adults with mild cognitive impairment. Journal of Alzheimer’s Disease 57, 1197–1205 (2017).
8. Australian and New Zealand Society for Geriatric Medicine. Australian and New Zealand Society for Geriatric Medicine Position Statement No. 11 Driving and Dementia. (2009).