Assessing Fitness to Drive

Table of Contents

8.2.2 Identifying and managing people at high crash risk

Until the disorder is investigated, treated effectively and licence status determined, people should be advised to avoid or limit driving if they are sleepy, and not to drive if they are at high risk, particularly in the case of commercial vehicle drivers. High-risk people include:

  • those who experience moderate to severe excessive daytime sleepiness (Epworth Sleepiness Scale score of 16–24)
  • those with a history of frequent self-reported sleepiness while driving
  • those who have had a motor vehicle crash caused by inattention or sleepiness.

People with these high-risk features have a significantly increased risk of sleepiness-related motor vehicle crashes (odds ratio 15:2). These people should be referred to a sleep disorders specialist, particularly in the case of commercial vehicle drivers. Driving limitations may include avoiding driving at night and after consuming alcohol or sedative drugs, and limiting continuous driving (e.g. to between 15 minutes to two hours depending on symptoms) until effective treatment is implemented – refer to section 8.2.5 Advice to patients.8