When Should Someone with Lewy Body Dementia Stop Driving?

Driving with Lewy body dementia is dangerous, and it becomes more dangerous as the disease progresses. Most families know this, but the conversation about when to stop is one that many put off longer than they should. Your loved one may have been driving for fifty years, and the car likely represents independence, competence, and a piece of the life they had before the diagnosis. Taking that away can feel cruel, or at least like something that can wait until later.

But LBD affects the specific cognitive and physical abilities that safe driving requires, and it does so early in the disease. The question is not whether driving will eventually become unsafe. It will. The question is how to recognize when that point has arrived and how to handle what comes next.

Why LBD Makes Driving Particularly Dangerous

Several symptoms of Lewy body dementia directly affect the ability to drive safely, and some of them make LBD more dangerous behind the wheel than other types of dementia.

One of those symptoms is cognitive fluctuation, where your loved one’s alertness, reaction time, and decision-making ability can change significantly within a single day. A person who drives to the pharmacy safely in the morning might be substantially impaired by midday, and there is no way to predict when a bad period will hit.

People with LBD can also experience visual hallucinations while behind the wheel. Seeing a person, child, or animal on the road that is not actually there, and swerving or braking in response, is a serious safety risk to your loved one and to everyone around them.

LBD also affects the ability to judge distances, depths, and the position of objects in relation to each other. This makes it harder to navigate lanes, judge gaps in traffic, and park safely. These difficulties can develop before obvious memory problems, which means families may not yet recognize them as part of the disease.

Slowed processing speed is another concern, because a driver with LBD has less time between perceiving a hazard and reacting to it, which in a fast-moving situation can mean the difference between stopping in time and not.

Warning Signs to Watch For

There are warning signs that tell you it is time for someone with LBD to stop driving.

1. Getting lost in familiar areas. If your loved one is losing their way on routes they have driven for years, their spatial awareness and memory are being affected in ways that make driving unsafe.
2. Unexplained scrapes or dents on the vehicle. These often go unmentioned or unnoticed by your loved one, but they indicate that something is happening on the road or in a parking lot that they are not fully aware of.
3. Driving unusually slowly or erratically. Significant changes in driving behavior, whether too fast, too slow, or unpredictable, suggest that their ability to process and respond to traffic is declining.
4. Missing stop signs or traffic lights. This is one of the clearest signs that attention and visual processing are impaired, and it puts everyone on the road at risk.
5. Difficulty judging distances when parking. Repeated trouble with parking, pulling too close to other cars, or misjudging curbs reflects the depth and distance perception problems that LBD causes.
6. Other drivers or passengers expressing concern. If someone who has been in the car with your loved one raises a concern, take it seriously.

One of the challenges with LBD is that your loved one may have limited awareness of these changes, particularly during a better cognitive period. They may believe they are driving as well as they always have. Asking a trusted family member to ride along as a passenger, without presenting it as an assessment, can give you a clearer picture of what is actually happening on the road.  Keep in mind that this should be done more than once because of the fluctuations and good days/bad days.

Getting a Formal Evaluation

If you are unsure whether your loved one’s driving has reached an unsafe point, a formal evaluation can help. Occupational therapists who specialize in driving rehabilitation offer assessments that include both cognitive testing and an on-road component, and the documentation they produce can be useful when it is time to have a difficult conversation with your loved one.

Your loved one’s neurologist can also assess driving risk as part of a regular appointment. In some states, physicians are permitted or required to report unsafe drivers to the DMV, so asking the neurologist directly whether they have concerns can take some of the burden off you and the rest of the family.

Having the Conversation

When you are ready to have this conversation, choose a time when your loved one is having a good cognitive day. Focus on specific things you have observed, such as a near-miss you witnessed  or damage to the car, rather than general statements about their ability. Framing the concern around safety for everyone on the road can make it easier to hear. Something like “I worry about what happens if a child runs into the road and you need to stop fast” opens the conversation without making your loved one feel like they are being judged.

This conversation rarely resolves in one sitting, so expect resistance the first time and be prepared to revisit it. If the situation is not immediately dangerous, give your loved one time to sit with the idea before pressing for a final decision.

If your loved one continues driving despite your concerns and you believe they are a genuine risk to themselves and others, contact their neurologist or another physician or person they trust. A physician’s documented concern is often enough to trigger a formal DMV assessment.

After Driving Stops

For many people with LBD, driving was one of the last things that still felt normal, so taking that away from them can be quite difficult to bear.

When it is time to move forward, help your loved one build a plan that keeps them as independent as possible. Family and friends can cover regular trips, ride services offer flexibility for outings, volunteer driver programs through local senior services are available in many areas, and medical transportation can handle appointments. Having a plan in place before the keys are handed over can help make the transition easier for everyone.

Helpful Resources

These organizations offer additional information and tools for families dealing with driving safety decisions.

• AARP: We Need to Talk – a free guide and virtual seminar on having the difficult driving conversation with a loved one
• AAA Senior Driver Safety & Mobility – driving assessments, the CarFit vehicle safety program, and the RoadWise refresher course for older drivers
• NHTSA: Driving Safely While Aging Gracefully – tips, resources, and information on how medical conditions affect driving ability
• NIA: Safe Driving for Older Adults – the National Institute on Aging’s guide to evaluating driving ability, including a self-assessment tool

Knowing when someone with Lewy body dementia should stop driving is one of the hardest decisions families face. If you need guidance on this or any other care decision, call our helpline at 516-218-2026 or 833-LBD-LINE. We are available every day of the year from 8am to 8pm Eastern time. You can also reach us by email at norma@lbdny.org.