If you think the car near you is being driven by someone drunk, put distance between your vehicle and theirs, pull into a parking lot or onto a safe shoulder, and call 911. That single call is what to do when you see a drunk driver, and it’s what gets police on the scene before anyone gets hurt. Alcohol-impaired driving killed 13,524 people in the United States in 2022, roughly a third of all traffic deaths that year.
Make Sure It Looks Like Impairment
You don’t need to be certain. You just need a reasonable basis. The National Highway Traffic Safety Administration has catalogued 24 visual cues of impaired driving, and a few patterns stand out as the ones bystanders actually notice.
Weaving within a lane, drifting toward the shoulder or center line, straddling a lane marker, or swerving abruptly to correct are the most recognizable. A driver weaving at night has roughly a 60% chance of being legally impaired according to NHTSA research, and the probability climbs when more than one cue shows up together. Wide, sweeping turns through intersections fit the same category.
Speed problems are another cluster: alternating between speeding up and slowing down for no reason, traveling 10 mph or more below the limit, or stopping jerkily and well short of or past where a stop sign calls for. Driving without headlights after dark, going the wrong way on a one-way street, tailgating, and drifting onto a shoulder or sidewalk all count too. Any one of these in isolation could have an innocent explanation. Two or more together should raise serious concern.
Keep Your Distance
Don’t flash your lights, honk, or try to signal the driver. An impaired person behind the wheel is unpredictable, and anything that gets their attention puts you in the path of their next bad decision. If they’re ahead of you, increase your following distance significantly. If they’re coming at you from the opposite direction, move as far to the right as you safely can and slow down.
Don’t try to follow closely, box the car in, or match its speed on a highway. The right move is to note what you can and let the car go. Pull into a parking lot, rest area, or wide shoulder before you make the call. If you have a passenger, hand them the phone and keep your eyes on the road.
What to Tell the 911 Dispatcher
Call 911 when the danger feels immediate: a vehicle crossing the center line, going the wrong way, nearly hitting other cars, or weaving erratically at highway speed. For something less urgent, like a car parked with the engine running and a seemingly impaired person at the wheel, use your local police non-emergency line. Many state highway patrol agencies also publish a dedicated short-dial number for cell phones. Look yours up and save it in your contacts before you ever need it.
When the dispatcher answers, give them:
- The vehicle’s make, model, and color, plus the license plate if you can read it without tailgating or fumbling with your phone.
- Your location: road name, direction of travel, nearest cross street or mile marker, and any landmarks.
- What you actually saw, in plain language. “The car crossed the center line three times in about a mile” is more useful than “driving erratically.”
Use a hands-free device if you have one. If you don’t, pull over before calling. Becoming a distracted driver yourself while reporting one doesn’t help.
Can You Report Anonymously?
Yes. You can ask for anonymity when you call 911, and dispatchers will generally honor it. If what’s holding you back is the fear of ending up in court, the practical reality is that drunk driving cases are built on what officers find after the stop: field sobriety tests, breath tests, blood tests. Your call gets police to the scene. Their investigation carries the case from there.
In 2014, the U.S. Supreme Court held in Navarette v. California that an anonymous 911 tip reporting a potentially drunk driver gives police enough reasonable suspicion to pull the vehicle over, even if officers don’t personally witness erratic driving before the stop. The Court reasoned that a 911 caller is reporting from firsthand observation, usually close in time to the behavior, and that the 911 system allows calls to be traced, which discourages false reports. Your call carries real legal weight and won’t be brushed aside because you didn’t leave your name.
What Happens After You Hang Up
Your part is essentially done. The dispatcher may ask you to stay on the line briefly or give updates if you still have the car in sight from a safe distance, but you are never required to follow, and you shouldn’t. Getting back into close proximity recreates the danger you just escaped and can complicate the police response if officers mistake your car for the one they’re looking for.
Officers in the area will watch for the described vehicle along the reported route. When they locate it, they’ll look for a traffic violation or driving behavior that independently justifies a stop, then look for signs of impairment up close: slurred speech, the smell of alcohol, difficulty handling a license and registration. The rest of the case is built from what they document from that point forward.
When the Drunk Driver Is Someone You Know
The more common version of this scenario isn’t a stranger on the highway. It’s someone at a party or a bar reaching for their keys after drinking too much. Here, 911 is the last resort, not the first.
NHTSA’s advice is straightforward: take their keys and help them arrange a sober ride. Call a rideshare, a taxi, or another friend. Offer your couch. The conversation can feel awkward. It’s vastly less awkward than the alternative. If the person refuses all help and insists on driving anyway, calling police is appropriate, even for someone you know.