On Sunday, November 1, the clocks fall back and the evening commute in Ogden moves into the dark. Sunset comes a little after five, the first real storms of the season arrive on the benches, and the mule deer migrating down to the valley floor cross Harrison Boulevard, US-89 and SR-39 at exactly the hours people are driving home. For a DUI defense practice, the change of season changes the cases: how the stop starts, what the officer writes down, and which defenses are available.
More stops begin with equipment, not driving
Utah Code § 41-6a-1603 requires vehicle lights from sunset to sunrise and whenever people or vehicles on the road are not clearly visible at 1,000 feet. In July that rule is irrelevant at 6 p.m. In November it is in force during the evening rush, and a burned-out headlight, a dim taillight, or a driver who pulled out of the Walmart lot with the automatic lights overridden is an infraction and a lawful reason for a stop.
Under Whren v. United States, an officer who observes a traffic violation can stop the car regardless of what the officer was really interested in. Utah follows that rule. What the law does not allow is extending the stop beyond its purpose without new suspicion. A headlight stop should be a headlight stop: license, registration, a warning or a citation, and done. When it becomes “Have you had anything to drink tonight?” the officer needs an articulable reason — odor, slurred speech, something seen in plain view — and the body-camera video has to support it. Our page on your rights at a traffic stop covers the line, and the suppression motion is where it gets tested.
Weaving, slush, and reasonable suspicion
“Observed vehicle weaving within its lane” is the sentence that starts more Utah DUI reports than any other. In a November storm on I-15 between Riverdale Road and Layton Parkway, it describes every car on the road. Ruts, slush in the lane lines, wind off the lake across the Farmington causeway, and the glare of oncoming headlights on wet asphalt produce exactly the lateral movement that officers are trained to call an impairment cue.
The stop may still be lawful; the standard is only reasonable suspicion. But the same conditions become the defense later. The dash-camera video that shows the driver drifting also shows what the road looked like, and a jury that has driven I-15 in a storm does not need an expert to understand it. We obtain that video in every case, and we obtain it fast, because agency retention windows are short.
November is deer-crash month
The Utah Division of Wildlife Resources says November is the peak month for deer-vehicle collisions in Utah, as migrating deer move to lower elevations and the end of daylight saving time puts the evening commute into the same low-light hours when deer are most active. The last statewide estimate put the number around 10,000 collisions a year. The corridors around Ogden — US-89 through Pleasant View, SR-39 up the canyon, I-84 through Weber Canyon, Harrison Boulevard along the bench — are all on the migration routes.
Hitting a deer is not a crime. What it produces is a trooper, a crash report, and a conversation. The trooper is trained to look for impairment at every crash, and a driver who was never going to be stopped is now standing on the shoulder at 6:30 p.m. being asked what she had with dinner. A glass of wine at a restaurant in the Ogden Valley, followed by a deer on SR-39, is a DUI investigation. Answer the questions the crash report requires. Decline to narrate the evening. Nothing in Utah law requires you to perform field sobriety tests at the scene of a crash that was the deer’s fault.
Field sobriety tests on a cold shoulder
The standardized tests — horizontal gaze nystagmus, walk-and-turn, one-leg stand — were validated under conditions that a November roadside in Utah does not provide. The NHTSA manual that every Utah officer is trained on says the walk-and-turn should be conducted on a reasonably dry, hard, level, non-slippery surface. It says the subject should face away from flashing lights during the eye test. It acknowledges that age, weight, leg and back problems, inner-ear conditions, and footwear affect performance. A 30-degree shoulder with a crown, gravel, slush, wind, and a light bar strobing behind the subject fails most of those conditions at once.
Cold does something else: it produces the “cues” on its own. Watery, bloodshot eyes from wind. A flushed face. Shivering that reads as swaying. Fumbling for a wallet with cold fingers that reads as impaired motor skills. Every one of those appears in reports as evidence of alcohol, and every one of them has a seasonal explanation that the video usually confirms. Our page on field sobriety tests explains how each test is scored and where it fails. The tests are voluntary; the breath test after arrest is not, and the difference is set out on our implied-consent page.
Cold medicine, allergy pills, and drug DUI
Fall is cold and flu season, and the medicine cabinet is a DUI exposure most people have never considered. Utah charges drug DUI two ways. Section 41-6a-502(1)(b) prohibits driving while impaired by alcohol, any drug, or the two combined, to a degree that makes the driver incapable of safely operating. Section 41-6a-517 prohibits driving with any measurable amount of a controlled substance or its metabolite in the body, impairment or not.
Over-the-counter antihistamines and sleep aids — diphenhydramine, doxylamine, the sedating components of most nighttime cold formulas — are not controlled substances, so the metabolite statute does not reach them. But the impairment theory does, and § 41-6a-504 states flatly that being legally entitled to use a drug is not a defense. A driver who took a nighttime cold medicine at 4 p.m. and got stopped for a headlight at 6 is a drug-DUI case if the officer documents drowsiness, slow responses, and a poor walk-and-turn. The State will usually bring in a drug recognition evaluator, and the DRE protocol has its own weaknesses that we examine line by line.
Prescription medications are a different category. Codeine cough syrup, a benzodiazepine for sleep, and most prescription painkillers are controlled substances; a valid prescription keeps the metabolite charge off the table only within the statute’s narrow safe harbor, and it is never a defense to the impairment charge. Combining any of them with a glass of wine at dinner is the fact pattern prosecutors like best, because the combination standard in § 41-6a-502(1)(b) is written for it.
Breath testing in the cold
Utah’s evidentiary breath test requires a 15-minute observation period before the sample, during which the subject must not burp, vomit, or put anything in the mouth. In a season when a stop happens in the dark on a shoulder and the subject has been shivering in a patrol car for 20 minutes, the observation period, the instrument’s calibration log, and the temperature of the sample all matter. A reading at or near 0.05 leaves no room for the instrument to be off by the margin its own manufacturer acknowledges. Our page on breathalyzer challenges covers the records we request in every case.
What to do if a fall stop turns into a DUI arrest
- Say as little as possible, politely. Produce documents. Decline to answer questions about drinking or medication.
- Decline field sobriety tests. There is no license consequence for declining in Utah, and the conditions on a November shoulder are not the conditions the tests were designed for.
- Do not refuse the chemical test after arrest without understanding the implied-consent penalty.
- Request the DLD hearing within 10 days. Under the 2026 amendments the suspension itself now starts on day 60, but the 10-day request deadline is unchanged.
- Write down the conditions. Weather, road surface, footwear, lighting, how long you stood outside, what medication you had taken and when. These details fade in a week and decide cases in a year.
Cardon, Stuart & Associates defends DUI cases in Weber and Davis County every week of the year, and the cases that start in November are the ones where the conditions of the stop matter most. Call (801) 627-1110. Our staff answers 24/7 and every case assessment is reviewed personally by an attorney.