Many people with dementia are able to drive safely for some time after diagnosis. However, research shows that the longer a person with dementia continues to drive after diagnosis, the greater the chances of getting into an accident. The changes the person with dementia is experiencing are much more complex than the changes people without dementia experience like eyesight issues and slower reaction time. As a result, the person with dementia is not the best person to assess their own driving ability. For example, as you have likely already identified, the person with dementia may:

• Have lost a range of brain functions that are necessary to make the kind of fast decisions and have the quick reactions necessary to drive safely.
  
• No longer be able to make new memories or learn new skills. It’s common that they will not recognize driving difficulties or be able to develop new behaviours to adjust to these changes.
  
  

 Inevitably dementia makes driving unsafe in numerous ways such as:

• Increasing forgetfulness
• Limited attention span
• Limited ability to quickly process information
• Poor judgment and problem-solving ability
• Disorientation to place
• Low reaction ability
• Visual perceptual issues (how things are seen in space, in relation to each other)

Watch this example of how dementia affects driving.

Source: National Highway Traffic Safety Administration