Using Your Lane Too 

Westbound Highway N approaching Schaper Road (St. Charles County, MO). The Honda Pilot in front of varies their speed between 40 MPH and an estimated 65 MPH and has difficulty staying in their lane.
At approximately 10 seconds into the video the Pilot veers into opposing traffic’s lane while there is oncoming traffic.
I followed the Pilot to the intersection of Highway M and Highway OO (Warren County; the one day a deputy was not sitting there). When then the vehicle turned south on Highway M, they turned into the northbound lane, then cutoff a Pontiac G6 in the southbound lane. Fortunately, even with the rain the driver of the G6 was able to slow down before hitting the Pilot.