For many older adults, driving an automobile is their preferred option for community transportation. Medical disorders that impair driving in older adults may have two serious adverse outcomes: injury or death resulting from a motor vehicle crash (MVC) or driving cessation.
Safe driving requires the integration of complex visual, motor, and cognitive processes, and older drivers with medical disorders may have mild to moderate deficits in one or more of these domains. Many older drivers successfully modify their routines and compensate for deficits by avoiding rush hour, driving fewer miles per year, limiting trips to shorter distances, and avoiding driving during twilight, nighttime, or inclement weather. Also, older drivers tend to be more cautious, drive more slowly, and take fewer risks. They also are cited less often for driving under the influence of alcohol. However, some older adults, because they deny or lack insight regarding limitations (eg, impaired judgment) or have a strong desire to maintain independence, continue to drive despite significant impairment of skills that relate to safe driving ability.
Most MVCs involving older drivers occur during the daytime and on weekdays. These MVCs often result from failing to yield the right-of-way, not heeding stop signs or red lights, or not maintaining proper lane positioning and tend to occur in more complex driving situations such as those that involve intersections, making left turns, or merging into traffic. MVCs involving older drivers are more likely to involve multiple vehicles and to result in serious injuries and fatalities than MVCs involving younger drivers.
Unlike in younger drivers, alcohol, texting, cell phone use, and speeding rarely play a role in MVCs involving older drivers; however, this situation may change in future aging cohorts. Distractions in the car could become more frequent as in-vehicle technology becomes more widespread (eg, GPS devices).
When MVCs do occur, older adults are more vulnerable to injury. The reasons for this vulnerability have not been well studied but may include the following:
Older drivers have diminished capacity to withstand trauma.
Older drivers often have more comorbidities (eg, osteoporosis, heart disease).
Many MVCs are driver-side impact (eg, occur while making left turns), making the older driver more vulnerable and likely to be injured.
Older drivers may operate a vehicle that is less crashworthy.
Statistics
According to the Insurance Institute for Highway Safety, there were about 30,000,000 licensed drivers age 70 and over in the US in 2019 (1). Older adults are maintaining their driver's license longer; the proportion of people age 70 and older with licenses increased from 73% in 1997 to 83% in 2019. Older drivers also on average are driving more miles per year, although still fewer miles than middle-aged drivers.
In 2019, 5195 people age 70 and older died in MVCs on US roads, representing a 12% decrease from 1997. However, older adults are increasingly involved in fatal MVCs on a percentage basis, compared to other age groups given an increase in the size of the aging cohort in the population.
Assessment
Health care practitioners become involved in driving decisions when deficits are identified during routine examination, a serious medical condition or illness manifests, patients solicit advice, family members express concern, or law enforcement cites unsafe driving behaviors. The role of practitioners is to do detailed functional and medical assessments related to driving safety.
National guidelines on driving and dementia include 8 evidence-based observations and recommendations (2):
Caregiver concerns should be taken seriously.
Diagnosis of dementia alone is not sufficient to withdraw driving privileges.
Individuals in the moderate phase of dementia are unlikely to be safe drivers.
People with dementia with progressive loss of 2 or more instrumental activities of daily living (IADL) due to cognition decline (but no loss of basic activities of daily living) are at higher risk of driving impairment.
People with deficits in IADL due to cognitive decline should have a formal assessment and ongoing monitoring of driving if they wish to continue to drive.
Abnormalities on cognitive screens may indicate an at-risk driver who is in need of further assessment; however, no in-office test or battery of tests including global cognitive screens (eg, Mini-Mental State Exam [MMSE], Montreal Cognitive Assessment [MoCA]) have sufficient sensitivity or specificity to be used as sole determinants of driving ability in all cases.
People with dementia who are deemed fit to continue to drive should be re-evaluated every 6 to 12 months (or sooner if indicated).
Driving history should be reviewed; details of driving habits and past violations, MVCs, close calls, or getting lost may point to general or specific impairments. Because older drivers with cognitive impairment may have poor insight, a significant other should be involved in this review. Caregiver reports (especially from an adult child) have been shown to be helpful indicators of driving performance, especially in older drivers with dementia (3, 4). The Alzheimer's Association's warning signs of unsafe driving include the following (5):
Forgetting how to locate familiar destinations
Not obeying traffic signs
Making slow or poor decisions while driving
Driving at an inappropriate speed
Becoming angry or confused while driving
Hitting curbs
Not keeping within lanes
Making errors at intersections
Confusing the gas and brake pedals
Returning late from a routine drive
Forgetting the destination during a drive
Some impairments may obligate practitioners to refer a patient to the state Department of Motor Vehicles for additional testing or driving restrictions. A review of current state license renewal laws reveals varying renewal cycles and testing requirements (see also the Insurance Institute for Highway Safety/Highway Loss Data Institute's license renewal procedures by state).
References
1. Insurance Institute for Highway Safety/Highway Loss Data Institute: Older drivers. Accessed 3/10/22.
2. Rapoport MJ, Chee JN, Carr DB, et al: An international approach to enhancing a national guideline on driving and dementia. Curr Psychiatry Rep 20(3):16, 2018. doi: 10.1007/s11920-018-0879-x
3. Barco PP, Wallendorf M, Blenden G, et al: Caregiver prediction of driving fitness in older adults with dementia. Clin Gerontol 44(5):520–527, 2021. doi: 10.1080/07317115.2021.1872130
4. Bixby K, Davis JD, Ott BR: Comparing caregiver and clinician predictions of fitness to drive in people with Alzheimer's disease. Am J Occup Ther 69(3):6903270030p1–6903270030p7, 2015. doi: 10.5014/ajot.2015.013631
5. Alzheimer's Association: Dementia and driving: Signs of unsafe driving. Accessed 3/10/2022.
Key Points
Driving cessation is inevitable for many older adults and can have negative outcomes (eg, social isolation, depression, fewer driving destinations).
Age-related and disease-related changes in physical, motor, sensory, and cognitive function can impair driving ability and account for some of the increase in motor vehicle crash (MVC) rates per miles driven in older drivers.
Many older drivers self-regulate their behavior.
Older adults are more vulnerable to injury and death in an MVC than other are age groups.
In-office tests and cognitive screens can identify at-risk drivers who need further assessment, but these tests are neither sensitive nor specific enough to be the sole determinant of driving ability.
People with dementia who are deemed fit to continue driving should be re-evaluated every 6 to 12 months (or sooner if indicated).
More Information
The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Geriatrics Society: Clinician’s Guide to Assessing and Counseling Older Drivers, 4th Edition
Austroads (Australia): Assessing Fitness to Drive
National Highway Traffic Safety Administration: Older Drivers: A resource providing driving safety information to older drivers and their caregivers
National Highway Traffic Safety Administration: Traffic Safety Facts, Older Population (2019 Data)
