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.