Yes — it is illegal to drive under the influence of marijuana in Maine.
Operating a motor vehicle while impaired by cannabis is considered an OUI (Operating Under the Influence) offense. This applies even if you're a medical marijuana patient or if the cannabis was legally obtained. Additionally:
Using marijuana inside a vehicle is also prohibited, regardless of who’s driving.
Law enforcement may conduct field sobriety tests or request chemical testing if impairment is suspected.
Violations can result in fines, license suspension, and other legal consequences.