How does cannabis use affect a person’s driving ability?

Cannabis use can impair:

  • reaction time
  • decision-making
  • time and distance perception
  • short-term memory
  • hand-eye coordination
  • concentration.

As a result, driving under the influence of cannabis can increase the risk of a crash by up to 300%. Furthermore, driving skills can be negatively affected for up to five or more hours after using cannabis. Using cannabis and alcohol together, even at low doses, also has a larger negative effect on driving than either cannabis or alcohol use alone.

For more information about cannabis visit the National Cannabis Prevention and Information Centre (NCPIC).