A driver in Northern California faces DUI charges after being discovered slumped and unconscious behind the wheel while his self-driving car navigated through bustling city streets, officials reported.

The unsettling incident occurred shortly after 11 a.m. on Wednesday in Vacaville, located about 35 miles southwest of Sacramento. A vigilant resident alerted authorities to a driver who appeared to be unconscious, prompting a 911 call, according to the Vacaville Police Department.

More troubling, however, was the fact that the vehicle was still in motion.

Police reported that the car continued to travel through traffic, posing a significant risk to other motorists. The caller remained on the line, offering real-time updates that enabled officers to locate and safely stop the vehicle near the intersection of Elmira Road and Shasta Drive.

Images released by the Vacaville Police Department depict the driver reclined in his seat, seemingly asleep, as the car idled in traffic.

Photos shared by the Vacaville Police Department show the driver leaned back in the seat, apparently asleep, as the vehicle sat in traffic.

But it’s what officers found inside the car that quickly raised red flags.

Items found inside the vehicle—including an open box of wine, a bottle and takeout food—after Vacaville police stopped a suspected drunken driver. (Vacaville Police Department)

Images released by the department show an open box of wine, a partially consumed bottle, and takeout food scattered across the passenger seat—along with other loose items inside the vehicle.

Investigators ultimately determined the driver was under the influence of both alcohol and marijuana. He was arrested on suspicion of DUI.

Police also drew strong reactions on social media after sharing images from the scene.

Vacaville Police Department officers responded to a dangerous alleged DUI incident involving a driver found unconscious behind the wheel. (Vacaville Police Department)

“That time when his vehicle had more situational awareness than he did,” one commenter wrote.

Others praised both the caller and responding officers for preventing a potentially dangerous crash.

“Glad no one was hurt. Great job of getting this guy off the road,” another user added.

The Vacaville Police Department noted that while newer vehicles may include assistive driving features, those systems are no substitute for a sober, alert driver.

Police also credited the quick-thinking caller for helping prevent what could have turned into a serious crash.

“Your calls help make our streets safer,” the department said.

Stepheny Price covers crime, including missing persons, homicides and migrant crime. Send story tips to stepheny.price@fox.com.