During a recent Parkinson’s Foundation webinar Harvard’s Margaret O’Connor, PhD, an expert in driving assessments, spoke on the subject of driving and Parkinson’s. While the mechanical skill of driving (procedural memory) often holds up well, PD can impact the complex cognitive and physical abilities needed for safe driving.

One of the most powerful points Dr. O’Connor made was the importance of getting an objective evaluation rather than relying on guesswork or difficult family conversations alone.

For many of us, driving represents freedom, independence, and connection. It’s how we get to appointments, visit loved ones, grab groceries, or just enjoy a spontaneous outing. Giving up the keys is a huge life change, often leading to fewer activities, potential isolation, and even increased risk of depression. Decisions about driving fitness need to be made thoughtfully, balancing independence with safety for everyone on the road

Dr. O’Connor detailed how both motor and non-motor symptoms of Parkinson’s can play a role:

• Motor: Slowness (bradykinesia) can delay reaction time to hazards. Balance issues can make getting in/out tricky (a swivel cushion can help). Limited neck rotation might impact checking blind spots (parabolic mirrors and increased scanning are strategies).

• Non-Motor (Often More Problematic): Attention is KEY. Difficulty multitasking (doing two things at once, like braking while monitoring traffic), processing information quickly, visual issues (like contrast sensitivity in fog), impaired judgment, and even fluctuations in alertness or sleep can significantly impact safety.

With regard to obtaining an objective evaluation of driving, Dr. O’Connor mentioned several resources. Social work support can help individuals and families talk through what stopping driving might mean and explore mobility alternatives to maintain autonomy. Occupational therapy (OT) evaluation can help with testing vision, physical function, and crucial cognitive skills like multitasking (using clinical tests). With objective testing, actual errors are noted in an evaluation, rather than vague concerns. Some new in-vehicle devices (plugging into the lighter port) can measure brake reaction time or speeding.

An OT department at a hospital is a good place to inquire about availability of driving programs in your state. Getting objective feedback from professionals can make the decision process clearer and less personal.

If you are lucky enough to live in the San Francisco Bay Area, note that Stanford has a driving simulator.

Decisions about driving with Parkinson’s are personal, complex, and carry significant emotional weight. Getting an objective assessment, understanding how your specific symptoms affect your driving, planning for alternatives, and having open conversations are vital steps.

A recording this webinar can be found on the Parkinson’s Foundation YouTube channel.

You can read more on this topic on the Stanford Parkinson’s Community Outreach Website: Driving and PD

You can read other past notes from webinars about driving and Parkison’s on the Stanford Parkinson’s Community Blog:

• PD and Driving: How to Steer Clear of Danger
• Parkinson’s and Driving (From a Caregiver’s Perspective)
• Driving and Road Safety for People with PD

And now, on with my notes.

– Elizabeth

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“Navigating the Road Ahead: Understanding Driving and Parkinson’s”

Speaker: Margaret O’Connor, PhD, Brigham and Women’s, Harvard Medical School
Host: Parkinson’s Foundation
Webinar Date: April 16, 2025
Summary by: Elizabeth Wong, Stanford Parkinson’s Community Outreach

In most states, there’s a very well-defined assessment that occurs when someone is beginning to drive, but there’s no strong protocol and no consistency in making decisions about when is the right time to stop driving.

What We Know About Driving

Driving is a complex activity that is dependent on all sorts of different cognitive and perceptual abilities, including:

• Processing speed
• Ability to scan the environment
• Sustained attention
• Mental flexibility/ multitasking such as ability to put on the brake while paying attention to the person next to you
• Social awareness
• Ability to survey the landscape of other people who are driving towards you and make a determination whether they’re driving safely or unsafely
• Motor control
• Visual acuity
• Contrast sensitivity, refers to the ability to discriminate an object from its background which can be compromised in dementia and in environmental conditions such as fog.

When making decisions about driving, take in consideration the following:

• Older adults who relinquish their licenses have fewer trips and activities.
• They may have more health problems, including a higher incidence of depression.
• It may be harder for them to get to the doctors or to get out and about, which might help mitigate the depression.

Who Should Start the Conversation of When to Stop Driving?

Study was done 30 years ago surveyed different stakeholder groups: about 300 physicians, the police, and community members, and each group looked to the other to make that decision.

Demographics and Age

In the United States, 74 million Americans will exceed age 65 by the year 2030 and more than 75% of them carry driving licenses.

• The average man outlives driving by six years.
• The average woman outlives driving by 10.

We did a comparison of 27 people who were aged 90 to 97 (old) versus 61 people who were 80 years old (the young old) and matched them for level of cognitive function, so both groups were at the same level in terms of their risk for dementia. Found that drivers who were 90 years old had no greater driving risk than those 10 years younger. Therefore, age in and of itself does not predict safety.

How Parkinson’s Disease Affects Safe Driving

Driving is a special kind of memory, called procedural memory. It is the mechanical skills that are involved in driving that support your ability to turn on the keys and operate the motor vehicle. Procedural memory remains strong with age and even in the context of dementia. It’s dependent on different neural circuits in your brain.

Every person with Parkinson’s is unique. There’s no one-size-fits-all approach. Therefore a personalized program is needed in order to ensure a fair and individualized decision.

There is not a lot of research on Parkinson’s but there’s this old study from Germany that surveyed 12,000 people who had been diagnosed with Parkinson’s and in that group, a high number still had a driver’s license and 60% were still driving; and 15% of that 60% reported a motor vehicle crash.

Many people with Parkinson’s disease self-restrict driving. They may not drive on the highway, they may not drive at night, they make modifications to keep themselves safe. We know that people with Parkinson’s disease may fail road tests at a higher rate compared to those who do not have Parkinson’s disease. In a meta-analysis, researchers didn’t find that there was an increased crash rate among drivers with PD in everyday life.

Motor and Non-Motor Symptoms Affecting Driving

The tremor is not necessarily problematic, but slowness is. Bradykinesia, slow reactions to hazards, may put you at risk for more crashes. Balance may affect your ability to get into and out of the car. The intervention for that could be use of a swivel cushion.

Some people may have neck rotation limitations which may make them more prone to make irrational decisions about lane changes. The intervention for that could be use of a parabolic mirror and increased scanning.

Non-motor symptoms are much more problematic.

• Contrast sensitivity, the ability to see the figure and discern it from the background is a problem that occurs in all different neurodegenerative diseases.
• Some people with impaired visual awareness can have problems making left turns.
• Some people with Parkinson’s have fluctuations in their level of alertness, in their level of attention, and in their level of sleep, therefore it would be important to monitor those symptoms when driving.
• Many people with Parkinson’s have executive deficits which affect multitasking and judgment. The most important aspect of cognition in terms of driving is multitasking. It’s being able to hit the brake pedal when you need to do it and at the same time be aware of all the other things around you simultaneously.
• Another thing that may undermine safe driving is processing speed.
• Some people have apathy and impulsivity, which may make them more risky in terms of driving or may make them slow to react.

The DriveWise Program (no longer in operation)

Dr. O’Connor and her colleague came up with a comprehensive program called DriveWise to address this issue. It’s no longer in operation because it never made money for the hospital, but during the time they had this program, they evaluated 1,200 drivers between the ages of 18 to 97. The program involved office-based testing such as a cognitive screening, a mental status exam (MoCA®), visual tests, a conversation about driving fitness with a social worker, and a road test. In our overall sample, about 43% of the people passed our evaluation, 62% of the people with Parkinson’s disease passed our road test.

The DriveWise assessment program included a social work evaluation/conversation that focused on the following:

• What does driving mean to a particular person?
• What other resources do they have? (Do they have access to Uber or public transportation?)
• What will life be like in the aftermath of not being able to drive? (Will they be totally dependent on family or can they figure out other ways to get around?)

After the social worker evaluates the personal needs of that particular person, they’re seen by an occupational therapist both in the lab and then undergo a road test with the occupational therapist and with a certified driving instructor. There were always two other people in the car, one with access to the brake pedal if needed.

The team (social work, occupational therapist, and neuropsychologist) would get together and they would write a very detailed letter with their evaluation and feedback, so the decision about their driving wasn’t being made on the basis of slim data. Then, they would have a session with the social worker to discuss evaluation results.

Useful Field of View Test

Divided attention or multitasking is particularly important in driving. The Useful Field of View Test is used to help determine driving fitness. Part one of the test, an object is shown in the middle of the field, and the test is to see how quickly someone can identify that object. Does it take them 30 milliseconds or does it take them a thousand milliseconds to detect whether something is a truck or a car?

During the test, the person is in front of the computer screen, and they are being asked to detect whether something, something will pop up on the screen (for example a car), then they are asked, “Was that a car or a truck?” They have to make that determination, and if it takes them an exceedingly long time to discriminate between whether that was a car or a truck, that’s a red flag for driving safety.

Part two of the test is seeing a car and then seeing an object in a different part of the space. The person has to identify the object in the middle as well as the other object, so they have to multitask. This part of the test is highly associated with driving difficulties.

Road Test Evaluation

After undergoing this in-office evaluation, people are often brought on the road, and these various aspects of driving are monitored:

• Can they start and secure the car?
• Can they follow instructions and road signs?
• Are they visually aware of their environment when they’re driving?
• Do they leave enough space between them and the car in front of them?
• Are they very good and in command of lane control?
• What are their maneuvers like? Are they impulsive? Are they slow? Or are they smooth?
• How do they respond to an obstacle and in a hazardous situation? Something that comes up.
• You want to look at speed of control as well as ability to navigate when something is different about the driving landscape.

Navigating Driving Cessation

A certain number of people do not pass the driving exam, in this case the role of the social worker is very important. An objective outside consultant (not family member or physician), the social worker who has access to the road test information, breaks that news. The social worker can involve the family to encourage open conversation, highlight people for their resilience, emphasize mobility alternatives and autonomy beyond driving, and prioritizing safety. Some people will say, “Would you have your grandchild in the car with you?” That sort of personalization of driving is sometimes helpful. It’s often helpful to assume a medical perspective. Explain how health changes, in particular vision, may impact driving ability. That’s easier to hear than cognition.

The Future of Driving Safety

• There have been efforts to redesign roads: to protect left turn signals, specified left turn lanes, reflective pavement markings, mixed-case lettering on road signs so it’s easier to see, and better lighting.
• One thing that’s worse, are the glare of headlights from other cars, which can be very blinding at times for all of us.

There are other things about car redesign that have been helpful to promote safe driving:

• Improved controls and door handles.
• An improved instrument panel.
• Collision warning systems and automated brake support.
• Some vehicle-to-vehicle communication systems.

Self-Driving Cars

If you are going to operate a self-driving car, Dr. O’Connor recommends that you learn it while your memory is still fully functional, so you can adapt to the technology that are involved in new cars while your memory will support you to do so, so that you can make them habits.

Some self-driving cars are fully independent and some are only partially independent. Sometimes the driver is more involved than in other cases.

Here are the latest in terms of assistance and autonomous driving innovations:

• Rivian features hands-free highway driving in the US and Canada, managing steering, acceleration, and braking. They use an infrared camera to ensure driver attentiveness.
• Mercedes-Benz® is partnering with a China company and is integrating LiDar (light detection and radar) sensors, which are laser-focused sensors focusing on three-dimensional objects in space. It is marketing the first use of the Chinese lidar technology in international markets, and that may enhance smart driving capabilities.
• Nissan® is testing fully autonomous vehicles on the streets in Japan. The driverless van relies on cameras, radars, and LiDar sensors to navigate. Nissan® plans to achieve full autonomy by 2029-2030.

There’s a little bit of a mix in terms of safety statistics, but autonomous vehicles for some people may be a good refuge if and when they stop driving.

Cost

Medicare does not pay for driving evaluations. They tend to range about $600. A letter to JAMA Neurology was written this year saying that it’s time for Medicare to pay for driving evaluations.

Q: Where can people go for a driver evaluation to receive that objective information about someone’s ability to drive?

A: They’re very state-dependent. Some states have more than others. The driving assessment programs tend to be located in occupational therapy departments of hospitals. Start with an OT department in a hospital.


Q: What are some compassionate and effective ways to approach this topic of driving cessation with a loved one?

A: I do think medicalizing the problem helps. They might be able to accept it if it feels like a medical problem. Point to particular issues having to do with coordination, having to do with vision, or other things that get in the way can be helpful. It would also be helpful to figure out the most thoughtful way forward in terms of maintaining independence. It could mean moving to a more urban area, where they have access to a local coffee shop, or whether they need to learn how to use Uber or use something else that allows them to get around so that they don’t have to always feel dependent on family members to get around.


Q: What are some signs or indicators that suggest it might be time to consider stepping away from driving?

A: If someone’s having fender benders, if they’re having those sorts of minor mishaps that seem benign at first, but if they occur over time, you might consider having someone in your family go out with you for a drive and see whether you are driving as well as you always did.

Another sign would be if someone’s beginning to have difficulty with attention, such as if someone is not able to sustain focused attention or they’re not able to do two things at once. Another sign of driving problems is noticing that they make impulsive moves when they’re driving such as haphazardly going in the wrong lane.


Q: Is anything else that you could offer for someone who’s navigating Parkinson’s solo?

A: There are new in-vehicle measuring devices that can be put in where you used to put your lighter, that can measure brake reaction time, that can measure whether you’re speeding. There are different insurance companies that will provide some sort of rapid analysis of your driving behaviors. Also consider talking to your doctor and trying to find out whether there is a driving assessment program in your vicinity.


Q: Can occupational therapy help with my control of the steering wheel as I have weakness in my left hand and sometimes it tremors on the wheel?

A: Hard for me to say, because I haven’t met you, but I think it’s worth a question to the occupational therapist and to the neurologist who is overseeing your care.


Q: Do you know if our car insurance companies raise premiums for people with Parkinson’s?

A: I don’t think they do, but there are some states where there is mandatory reporting. So if someone has a cognitive impairment related to Parkinson’s, there are six states across the United States – including California – where if you see a provider, a mental health provider or neurologist, anybody, they are mandated to report you to the registry of motor vehicles and that in turn will trigger a road test.


Q: Are people at a greater risk for driving errors if they are taking carbidopa/levodopa as opposed if they’re not using carbidopa/levodopa?

A: There’s a lot of heterogeneity in Parkinson’s disease. There’s also a lot of heterogeneity in how people react to medicine. If that medicine affects your level of arousal or if it affects attention or any aspect of your cognition, then that would put you at greater risk for driving errors, but if the medication does not impact you in that way, then it may not put you at greater risk of driving errors.


Q: Could you explain what heterogeneity means for those who might not understand?

A: In the context of Parkinson’s disease, some people have cognitive impairment and some people don’t, and they may just have more motor symptoms. I just mean differences in the manifestations of the disease and in your functional skill set.


Q: I was notified by my state that I had been reported as an unsafe driver due to my Parkinson’s disease. The state required me, at great expense, to go through the driving evaluation process. How can I defend myself in these situations and what recourse do I have in the future?

A: I don’t know if you have recourse. There are such differences across different states in terms of who to report, when to report, who can report, and whether or not they mask the identity of the person who reported. I don’t have good advice for you about how to defend yourself, but I’m really sorry that happened to you.