DEERFIELD — A 20-year-old Greenfield man was charged with driving under the influence of marijuana after a police officer noticed his vehicle driving well below the speed limit and over the double solid yellow line on Greenfield Road early Sunday morning.

Zachariah Lyman of Wells Street was arraigned on charges of operating under the influence of drugs and marked lanes violation in Greenfield District Court Tuesday.

According to a report by Deerfield Police Officer Dane Jobst, Jobst was on patrol on Greenfield Road around 1 a.m. when he noticed a vehicle pass him unusually slowly. He pulled out behind the car and saw it bounce back and forth between the center line and the fog line while continuing to drive 15 mph under the posted speed limit in some areas.

Jobst stopped the vehicle after it crossed the solid double yellow line and wrote in his report that the operator, identified as Lyman, had bloodshot, glossy eyes and extremely dilated pupils. Lyman admitted to smoking marijuana before driving, according to the report, and a series of field sobriety tests indicated he was impaired.

A preliminary breath test showed Lyman was not under the influence of alcohol at the time of his arrest.