Assessing Fitness to Drive

In this section

6.3.1. General assessment and management guidelines

6.3.2. Medical standards for licensing

People with neurological conditions should be examined to determine the impact on the functions required for safe driving as listed below¹. If the health professional is concerned about a person’s ability to drive safely, the person may be referred for a driver assessment or for appropriate allied health assessment (Box 3) (refer also to Appendix 10. Specialist driver assessors).

Aneurysms (unruptured intracranial aneurysms and other vascular malformations)

The risk of sudden severe haemorrhage from most unruptured intracranial aneurysms and vascular malformations is low enough to allow unrestricted driving for private vehicle drivers. However, the person should not drive if they are at high risk of sudden symptomatic haemorrhage (e.g. giant [> 15 mm] aneurysms). Cavernomas frequently produce small asymptomatic haemorrhages that do not impair driving ability. However, if they produce a neurological deficit, the person should be assessed to determine if any of the functions listed above are impaired. Commercial vehicle drivers should be individually assessed for suitability for a conditional licence.

If treated surgically, the advice regarding intracranial surgery applies (refer below). If the person has had a seizure, the seizures and epilepsy standards also apply (refer to section 6.2. Seizures and epilepsy).

Cerebral palsy

Cerebral palsy may impair driving ability because of difficulty with motor control or if it is associated with intellectual impairment. A practical driver assessment may be required (refer to Part A section 2.3.1. Practical driver assessments). As the disorder is usually static, periodic review is not normally required.

Head injury^{2, 3, 4, 5, 6}

A head injury will only affect driver licensing if it results in chronic impairment or seizures. However, any person who has had a traumatic injury causing loss of consciousness should not drive for a minimum of 24 hours, and the effects on functions listed above should be monitored. This is advisory and not a licensing matter.

Minor head injuries involving a loss of consciousness of less than one minute with no complications do not usually result in any long- term impairment. Similarly, immediate seizures that occur within 24 hours of a head injury are not considered to be epilepsy but part of the acute process.

More significant head injuries may impair any of the neurological functions listed in Box 3 and can impair long-term driving ability. There may be focal neurological injury affecting motor or sensory tracts as well as the cranial nerves. Also, personality or behavioural changes may affect judgement and tolerance and be associated with a psychiatric disorder such as depression or post-traumatic stress disorder. Clinical, neuropsychological or practical driver assessments may be helpful in determining fitness to drive (refer to Part A section 2.3.1. Practical driver assessments).

Comorbidities such as drug or alcohol misuse and musculoskeletal injuries may also need to be considered (refer to section 9. Substance misuse and section 5. Musculoskeletal conditions).

Neurological recovery from a traumatic brain injury may occur over a long period, and some people who are initially unfit may recover sufficiently over many months such that driving can eventually be resumed.

Risk of post-traumatic epilepsy

People with depressed skull fractures, traumatic intracranial haematoma or severe traumatic brain injury are at increased risk of epilepsy, especially in the first year. Commercial drivers therefore should not drive for 12 months after the injury and require a conditional licence. Private driving may continue, provided the person otherwise meets the standard to drive (refer to Head injury in table). If one or more seizures have occurred, the symptomatic seizures standard applies. Post- traumatic epilepsy should be distinguished from immediate post-traumatic (acute symptomatic) seizures occurring within 24 hours of a head injury, which are considered part of the acute process (refer to Acute symptomatic seizures).

Intracranial surgery (advisory only; non- driving periods may be varied by the neurosurgeon)

Non-driving periods are advised to allow for the risk of seizures occurring after certain types of intracranial surgery. Following supratentorial surgery or surgery requiring retraction of the cerebral hemispheres, the person generally should not drive a private vehicle for six months or a commercial vehicle for 12 months. Notification to the driver licensing authority is not required. There is no specific restriction after infratentorial or trans-sphenoidal surgery.

If one or more seizures occur, the standards for seizures and epilepsy apply (refer to section 6.2. Seizures and epilepsy), and the driver should notify the driver licensing authority. Similarly, if there is long-term impairment of any of the functions listed in Box 3, fitness to drive will need to be assessed (refer to section 6.3. Other neurological and neurodevelopmental conditions).

Ménière’s disease

Ménière’s disease may be accompanied by acute vertigo, which can affect driving. However, attacks are usually accompanied by a prodrome of fullness in the ear, which gives sufficient warning to cease driving. Drivers, particularly commercial vehicle drivers, warrant individual assessment by an ENT specialist regarding their ability to respond in a timely manner to an attack. Such commercial drivers need also to meet the hearing standard (refer to section 4. Hearing loss and deafness).

Multiple sclerosis⁷

Multiple sclerosis may produce a wide range of neurological deficits that may be temporary or permanent. Possible deficits that may impair safe driving include all of those listed in Box 3. Disease-modifying therapies are available that can slow or halt the progression of disability with long periods of stability without impairment for safe driving. Vehicle modifications may assist with some of the listed impairments; the advice of an occupational therapist may be helpful in this regard (refer to Part A section 2.3.1. Practical driver assessments).

Neuromuscular disorders

Neuromuscular disorders include diseases of the peripheral nerves, muscles or neuromuscular junction. Peripheral neuropathy may impair driving due to difficulties with sensation (particularly proprioception) or from severe weakness. Disorders of the muscles or neuromuscular junction may also interfere with the ability to control a vehicle. A practical driver assessment may be required (refer to Part A section 2.3.1. Practical driver assessments).

Parkinson’s disease^{8, 9, 10}

Parkinson’s disease is a common, progressive disease that may affect driving in advanced stages² due to its motor manifestations (bradykinesia and rigidity) or cognitive impairments (deficits in executive function and memory and visuospatial difficulties).³ There may also be disturbances of sleep, with episodes of sleepiness when driving. When assessing the response to treatment, the response over the whole dose cycle should be taken into account (e.g. in patients with motor fluctuations, it would not be appropriate to assesses fitness to drive only on the basis of the best ‘on’ response). Most patients with severe fluctuations will be unfit to drive. A practical driver assessment may be required (refer to Part A section 2.3.1. Practical driver assessments).

Stroke (cerebral infarction or intracerebral haemorrhage)^{11, 12, 13}

Stroke may impair driving ability either because of the long-term neurological deficit it produces or because of the risk of a recurrent stroke or transient ischaemic attack (TIA) at the wheel of a vehicle (refer over the page).

Stroke and TIA rarely produce loss of consciousness; it is very uncommon for undiagnosed strokes or TIAs to result in motor vehicle crashes. When they do, it is usually due to an unrecognised visual field deficit.

It is common for a person to experience fatigue and impairments in concentration and attention after a stroke, even in those with no persisting neurological deficits. These effects are normally temporary. The effects may temporarily impair the ability to perform the driving task, particularly for commercial vehicle drivers. For this reason, a minimum non-driving period applies to all drivers after a stroke (at least four weeks for private drivers and at least three months for commercial drivers).

Functionally significant symptoms or neurological deficits that are persistent after a stroke can affect activities of daily living including driving. For drivers with these deficits, subsequent driving fitness will depend on the extent of impairment of the functions listed in Box 3 and the likely impact on driving ability. A practical driver assessment may be required (refer to Part A section 2.3.1. Practical driver assessments). While many people with mild stroke are independent in many activities of daily living, they may have ongoing aphasia (comprehension of written and spoken language), which may impact on their fitness to drive. The musculoskeletal and vision standards may also apply (refer to sections 5. Musculoskeletal conditions and 10. Vision and eye disorders). If the person has had a seizure, the seizures and epilepsy standards also apply (refer to section 6.2. Seizures and epilepsy).

Private drivers without significant impairment (with respect to driving) of the functions listed in Box 3, may resume driving after the non- driving period without further medical review or licence restrictions. This also applies to patients assessed and discharged early from specialist care within the four weeks following a stroke, either as an inpatient or outpatient. If the person requires post-stroke rehabilitation their functional deficits may indicate impacts on driving capacity. Documentation of the assessment should be provided at discharge, which includes details of the driver’s licence, indicate that they have not suffered any permanent neurological deficits that will impact driving, and that they are fit to drive at the end of the non-driving period.

Some private drivers may require a conditional licence depending on the nature of the impairment. Conditions on the licence can include requirements for vehicle modifications, local area driving only, no night driving, or no freeway driving (refer to Part A section 4.4. Conditional licences). Periodic review is not normally required as these impairments are usually static. Reference should be made to the review requirements if musculoskeletal, vision or seizure standards apply (refer to sections 5. Musculoskeletal conditions, 10. Vision and eye disorders and 6.2. Seizures and epilepsy).

If symptoms or deficits improve, the driver licensing authority may consider removing the requirement for licence conditions (refer to Part A section 4.5. Reinstatement of licences or removal or variation of licence conditions).

Treatable causes of stroke (e.g. high blood pressure, atrial fibrillation or carotid stenosis) should be managed with reference to this standard. Patients should be encouraged to comply with stroke prevention therapy.

Transient ischaemic attack (advisory)^11,12,14

TIAs can be single or recurrent and may be followed by a stroke. Included under this definition are patients who may have minor infarction on neuroimaging but who have fully resolved symptoms and a normal neurological examination within a 24-hour period. TIAs may impair driving ability if they occur at the wheel of a motor vehicle. However, because a TIA almost never produces loss of consciousness, it is an extremely uncommon cause of crashes. The risk of a subsequent stroke with modern medical therapy is about 5 per cent in the first year and about half of that risk occurs in the first week. In view of the low risk of a TIA or stroke affecting driving, private vehicle drivers should not drive for two weeks, and commercial vehicle drivers should not drive for four weeks after a TIA. A conditional licence is not required because there is no long-term impairment (refer to Part A section 2.2.3. Temporary conditions).

Consumer Resources

The Stroke Foundation provides information and a fact sheet about driving after a stroke or transient ischaemic attack (TIA).

Subarachnoid haemorrhage

Driving should be restricted if the person has had a subarachnoid haemorrhage. Aneurysmal subarachnoid haemorrhage has a high chance of associated neurological injury and high rates of post-subarachnoid haemorrhage seizures. For such patients, a conditional licence may be considered after a minimum three-month non- driving period for private vehicle drivers and after at least six months for commercial vehicle drivers, taking into account the presence of neurological disabilities as described in Box 3. The vision standard may apply (refer to section 10. Vision and eye disorders). If the person has had one or more seizures, the seizures and epilepsy standards also apply (refer to section 6.2. Seizures and epilepsy). If a craniotomy has been performed, the advice for intracranial surgery also applies. A practical driver assessment may be considered (refer to Part A section 2.3.1. Practical driver assessments).

Minor non-aneurysmal subarachnoid haemorrhage restricted to the cerebral convexity is associated with a range of underlying neurovascular conditions (e.g. cerebral amyloid angiopathy and reversible cerebral vasoconstriction syndrome) with differing symptom associations and risks. For such patients, assessment of fitness will depend on the underlying aetiology and presence of neurological impairments as described in Box 3. The vision standard may apply (refer to section 10. Vision and eye disorders). If the person has had one or more seizures, the seizures and epilepsy standards also apply (refer to section 6.2. Seizures and epilepsy). If a craniotomy has been performed, the advice for intracranial surgery also applies (refer to page 153). A practical driver assessment may be considered (refer to Part A section 2.3.1. Practical driver assessments).

Space-occupying lesions including brain tumours^15,16

Brain tumours and other space-occupying lesions (e.g. abscesses, chronic subdural haematomas, cysticercosis) may cause diverse effects depending on their location and type. They may impair any of the neurological functions listed in Box 3. If the person has had one or more seizures, the seizures and epilepsy standards also apply (refer to section 6.2. Seizures and epilepsy). If a craniotomy has been performed, the advice regarding intracranial surgery also applies.

Other neurological conditions including autism spectrum disorder and other developmental and intellectual disabilities^{17, 18, 19, 20, 21}

The impact of other neurological conditions including autism spectrum disorder (ASD) and developmental and intellectual disability should be assessed individually. A practical driver assessment may be required. If the degree of impairment is static, periodic review is not usually required.

People with ASD can have differences in social communication and interaction, with restricted and repetitive patterns of behaviour, interest and activities. Although evidence from driving studies are limited, drivers with ASD may drive differently from people without ASD. Shortcomings in tactical driving skills have been observed, while rule-following aspects of driving are improved. There is considerable difference in the range and severity of ASD symptoms, so assessment should focus on these and the significance of likely functional effects, rather than an ASD diagnosis. People with ASD may have difficulty with:

• managing attention and distraction
• understanding non-verbal communication from other drivers
• planning and organisation of the driving task and adapting to unexpected change
• sensory sensitivities (e.g. glare and sound)
• emotional regulation and input overload
• repetitive behaviours such as rocking or hand flapping.

Requirements for unconditional and conditional licences are outlined in the following table.

The standards for medical conditions in the table below (in alphabetical order) cover:

• aneurysms (unruptured intracranial aneurysms and other vascular malformations)
• cerebral palsy
• head injury
• intracranial surgery
• Ménière’s disease
• multiple sclerosis
• neuromuscular conditions
• other neurological conditions
• Parkinson’s disease
• stroke
• transient ischaemic attacks
• space-occupying lesions including brain tumours
• subarachnoid haemorrhage.

References and further reading

1. 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)
2. Annegers, J. F., Hauser, W. A., Coan, S. P. & Rocca, W. A. A population-based study of seizures after traumatic brain injuries. New England Journal of Medicine 338, 20–24 (1998).
3. Christensen, J. et al. Long-term risk of epilepsy after traumatic brain injury in children and young adults: a population- based cohort study. The Lancet 373, 1105– 1110 (2009).
4. Baker, A., Unsworth, C. A. & Lannin, N. A. Fitness-to-drive after mild traumatic brain injury: mapping the time trajectory of recovery in the acute stages post injury. Accident Analysis and Prevention 79, 50–55 (2015).
5. Chee, J. N. et al. Risk of motor vehicle collision or driving impairment after traumatic brain injury: a collaborative international systematic review and meta-analysis. Journal of Head Trauma Rehabilitation 34, E27–E38 (2019).
6. Hawley, C. A. Return to driving after head injury. Journal of Neurology Neurosurgery and Psychiatry 70, 761–766 (2001).
7. Giovannoni, G. et al. Brain health: time matters in multiple sclerosis. Multiple Sclerosis and Related Disorders 9, S5–S48 (2016).
8. Heikkilä, V. M., Turkka, J., Korpelainen, J., Kallanranta, T. & Summala, H. Decreased driving ability in people with Parkinson’s disease. Journal of Neurology Neurosurgery and Psychiatry 64, 325–330 (1998).
9. Wood, J. M., Worringham, C., Kerr, G., Mallon, K. & Silburn, P. Quantitative assessment of driving performance in Parkinson’s disease. Journal of Neurology, Neurosurgery and Psychiatry 76, 176–180 (2005).
10. Classen, S. Consensus statements on driving in people with Parkinson’s disease. Occupational Therapy in Health Care 28, 140–147 (2014).
11. Rapoport, M. J. et al. A systematic review of the risk of motor vehicle collision after stroke or transient ischemic attack. Topics in Stroke Rehabilitation 26, 226–235 (2019).
12. Shahjouei, S. et al. A 5-decade analysis of incidence trends of ischemic stroke after transient ischemic attack: a systematic review and meta-analysis. JAMA Neurology (2020) doi:10.1001/jamaneurol.2020.3627.
13. Mohan, K. M. et al. Risk and cumulative risk of stroke recurrence: a systematic review and meta-analysis. Stroke 42, 1489–1494 (2011).
14. Lioutas, V. A. et al. Incidence of transient ischemic attack and association with long- term risk of stroke. JAMA: Journal of the American Medical Association 325, 373– 381 (2021).
15. Kerkhof, M. & Vecht, C. J. Seizure characteristics and prognostic factors of gliomas. Epilepsia 54, 12–17 (2013).
16. Mansur, A. et al. Driving habits and behaviors of patients with brain tumors: a self-report, cognitive and driving simulation study. Scientific Reports 8, 4635 (2018).
17. Chee, D. Y., Lee, H. C., Patomella, A. H. & Falkmer, T. Driving behaviour profile of drivers with autism spectrum disorder (ASD). Journal of Autism and Developmental Disorders 47, 2658–2670 (2017).
18. Brooks, J. et al. Training the motor aspects of pre-driving skills of young adults with and without autism spectrum disorder. Journal of Autism and Developmental Disorders 46, 2408–2426 (2016).
19. Lindsay, S. Systematic review of factors affecting driving and motor vehicle transportation among people with autism spectrum disorder. Disability and Rehabilitation 39, 837–846 (2017).
20. Wilson, N. J., Lee, H. C., Vaz, S., Vindin, P. & Cordier, R. Scoping review of the driving behaviour of and driver training programs for people on the autism spectrum. Behavioural Neurology (2018) doi: 10.1155/2018/6842306
21. Cox, N. B., Reeve, R. E., Cox, S. M. & Cox, D. J. Brief report: Driving and young adults with ASD – parents’ experiences. Journal of Autism and Developmental Disorders 42, 2257–2262 (2012).