Hallucinations Research is sparse, but pot-related cases can happen and are an “underappreciated” threat on the road.
Slower decisions Being high can impair users’ executive function and problem-solving ability. That makes it harder for drivers to make a smart choice—do I swerve or slam on the brakes?—on the fly.
Limited vision It’s harder to see events in your periphery. Pot causes a tunnel-vision effect, which impairs drivers’ ability to recognize obstacles to their far left and right.
Sluggish reflexes Pot can negatively affect the parts of the brain that coordinate and initiate movement, which makes it tougher to physically control a car.