WINONA, Minn. – The driver explained to police that his erratic driving about 1:20 a.m. was because he was trying to avoid potholes. He also admitted to marijuana a while earlier. After he failed field sobriety tests, and because his speech was slurred and because the car smelled of marijuana, police arrested Choua Lor, 44, of Winona. The car, police said, had a small clear bag of marijuana in a door compartment. Also, they said, Lor had marijuana in a pocket. How impaired was he? Results of a urine test were pending from the state crime lab. The arrest was at Howard and Zumbro streets, not far from his Belleview Street home.