Police in West Texas said Manuel Chico was arrested at the weekend after an off-duty officer spotted the pickup truck adorned with law enforcement gear.
The real officer who witnessed the act initially thought the driver, who was wearing a uniform, was a volunteer fireman, Odessa police Corporal Steve LeSueur said.
"I observed other vehicles in the drive-thru lane back up and move out of the way, submitting to the red and white flashing lights along with sirens that were very loud," the arresting officer wrote in his report.
Chico, 26, quickly came clean after the officer followed and confronted him outside some nearby apartments.
The fake cop told the officer that he used the lights and sirens to get through traffic signals.Chico was freed on $15,000 (£10,100) bond.