Hearkening to the old west days, a trail or route known to outlaws but not law enforcement. Two lane county roads that are not patrolled by state troopers or city police, and seldom patrolled by county law enforcement. Often dirt, gravel, or asphalt with no markings.
Voice of reason: "You reek of likker and can't walk, you shouldn't drive home."
Slurred response: "I'm not taking the interstate, I have an outlaw trail"