Legally Reviewed by Shazam Kianpour on August 25, 2026
They say that a fine wine gets better as it ages. The same is apparently not true of older drivers who drink fine wine.
Though there has been little mention of it in Denver media, a new study shows that older drivers are more affected by alcohol consumption than younger drivers. The study suggests that even when blood alcohol content (BAC) is below the DUI threshold, older drivers might feel the effects of alcohol.
The study was by a University of Florida professor of psychiatry and psychology. Participants were in one of two age groups: 25 to 35 years old or 55 to 70 years old.
Participants were all in the same height and weight ranges; the main difference between the two groups was age.
When researchers gave participants an amount of alcohol that got BAC to 0.065 percent, older drivers “seemed to exhibit jerkier steering and more variability in their speed,” a research assistant said.
In Colorado, the legal threshold for BAC is 0.08 percent.
The research assistant said both groups were given the same amount of alcohol, but that the effects of the alcohol were more pronounced in older drivers.
There is little doubt that alcohol has different effects on people of different ages, sizes, weights and so on.
A DUI arrest and conviction can have varying degrees of impact on people as well. For younger drivers, a DUI conviction can mean years of difficulties with job or educational opportunities. For older drivers, a conviction can mean career advancement is slowed or stopped. And auto insurance rates are likely to skyrocket no matter what the age of the driver.
All of the above makes it crucial for drivers facing DUI charges to speak with an experienced attorney about available legal options that can potentially lead to reduced or dismissed charges or a minimized impact on driving privileges.
Source: Alligator.org, “Older-adult drivers more impaired by alcohol, UF study says,” Katherine Arellano, March 12, 2014
Why Colorado’s BAC Threshold Does Not Tell the Whole Story
Colorado uses two related but distinct standards for alcohol-impaired driving. A driver with a BAC of 0.08 percent or higher can be charged under the state’s DUI per se standard, meaning the test result alone can support the charge regardless of how the driver appeared to be functioning. Below that threshold, a driver can still face a DWAI, or driving while ability impaired, charge if an officer believes alcohol affected the person’s driving to even a slight degree.
This distinction matters for older drivers because research like the University of Florida study suggests measurable impairment can appear well under 0.08 percent BAC. A prosecutor does not need a per se result to pursue a case, and officers are trained to document behaviors, such as lane drift or slowed reaction time, that can support a DWAI charge even at lower test results.
How Officers Build a DWAI Case Without a High BAC Result
When a breath or blood test comes back under 0.08 percent, officers and prosecutors typically rely on other observations to support impairment. These commonly include:
- Driving pattern: weaving, inconsistent speed, or delayed braking noted by the officer before the stop.
- Physical presentation: odor of alcohol, slurred speech, or unsteady movement during the stop.
- Field sobriety test performance: results from standardized tests administered roadside.
Each of these observations can be challenged. Field sobriety tests were originally validated for a general population and do not always account for age-related balance issues, medication use, or physical conditions that have nothing to do with alcohol.
Colorado’s Express Consent Law and Chemical Testing
Colorado’s express consent law requires drivers to submit to a breath, blood, saliva, or urine test once an officer has probable cause to believe they were driving under the influence. Refusing the test can trigger an automatic license consequence handled through a separate DMV proceeding, independent of whatever happens in the criminal case. Because these two tracks move on different timelines, a driver facing a DUI or DWAI charge often needs to address the license issue and the criminal case at the same time.
What This Means for Older Drivers Facing a DUI or DWAI Charge
A test result below 0.08 percent BAC does not mean a case will be dismissed, and it does not mean a case cannot be defended. The specific facts of the stop, the reliability of the testing equipment, and the officer’s observations can all be examined closely. For older drivers in particular, an attorney can also raise legitimate, non-alcohol explanations for balance or coordination issues that an officer may have attributed to intoxication.
Frequently Asked Questions About Colorado DUI and DWAI Charges
Can a driver be charged with DWAI even if their BAC is under 0.08 percent?
Yes. Colorado allows a DWAI charge when alcohol affects a driver’s ability to operate a vehicle to even a slight degree, regardless of the exact BAC. A test result below 0.08 percent does not prevent a DWAI charge from being filed.
What is the difference between a DUI and a DWAI in Colorado?
DUI applies when a person’s ability to drive is substantially impaired by alcohol or drugs. DWAI applies to a lesser degree of impairment and generally carries less severe penalties, though it remains a serious traffic offense in Colorado.
Can medical conditions be mistaken for alcohol impairment during a stop?
Yes. Balance issues, slower reaction time, or slurred speech can result from medication, fatigue, or an underlying medical condition rather than alcohol. These factors can be raised as part of a defense when they may have influenced an officer’s observations.
What happens if I refuse a breath or blood test in Colorado?
Refusing a test under Colorado’s express consent law can result in an automatic license consequence through a DMV hearing. This process runs separately from, and on a different timeline than, any related criminal DUI or DWAI case.
Are field sobriety tests always accurate?
Field sobriety tests are not always reliable indicators of impairment. Age, balance conditions, footwear, and roadside surface conditions can all affect performance regardless of alcohol consumption, which is why test administration is often scrutinized in a defense.
If you or a loved one is facing a DUI or DWAI charge in Colorado, the facts of the stop and the reliability of any test results can make a meaningful difference in how the case proceeds. Shazam Kianpour & Associates, P.C. has represented clients in Denver DUI cases for years. Contact our office to discuss your situation.
About the Attorney
Founder, Shazam Kianpour & Associates, P.C.
Shazam Kianpour is a Denver criminal defense attorney who has handled thousands of criminal and traffic cases across Colorado, including DUI, DWAI, and DMV hearing matters. He previously served as a Colorado State Public Defender and is a member of the Colorado Bar Association and the Colorado Criminal Defense Bar.
Written by
Shazam KianpourDenver Criminal Defense Attorney & Founder, Shazam Kianpour & Associates, P.C. — Over 10,000 criminal and traffic cases handled across Colorado.