Impaired driving is a dangerous and all too common crime. It's also preventable. Whether you're under the influence of alcohol or drugs, getting behind the wheel of a vehicle can cost you more than money and a night in jail. Every day, impaired or drunk driving accidents claim the lives of 37 people, according to the National Highway Traffic Safety Administration (NHTSA).
In response, states have been enacting stricter laws to discourage drunk driving. One of the more popular types is the “per se" intoxication law.
What are Per Se Intoxication Laws?
Per se laws in DUI or DWI cases generally mean that if you have a blood alcohol concentration (BAC) at or above the state's legal limit, the law considers you intoxicated. Law enforcement needs no further evidence of intoxication or impairment for a DUI case, as "per se" means “by itself" or “on its own."
These laws make it easier for prosecutors to establish your impairment. All states, except for Utah, have per se DUI laws that find any driver intoxicated with a BAC at or above 0.08%. The legal limit is lower if you operate a commercial vehicle, usually around 0.04%. In most instances, commercial drivers will also lose their commercial driver's license (CDL) for at least one year.
Utah recently changed its legal limit to 0.05% with great success. The National Transportation Safety Board (NTSB) has advocated since 2013 for states to reduce the per se intoxication limit to 0.05%.
These laws show the importance for people who drink to realize that, regardless of how sober you feel and behave, your BAC matters once you get behind the wheel.
Chemical Tests and Implied Consent Laws
Having a driver's license is a privilege. You're expected to follow the law and drive with care. If law enforcement reasonably suspects you are operating a motor vehicle while under the influence, they can ask you to submit to chemical tests and field sobriety tests. Implied consent laws mean you imply your consent to these tests when given your driver's license. While you have the right to refuse these tests, there are immediate consequences for not complying with them.
These tests may include a Breathalyzer to measure the level of alcohol in your system. You may also need a blood test, saliva test, or urine test to verify your BAC. If your BAC is at or above your state's legal limit, you face a per se charge of driving under the influence.
Underage Drivers and Zero Tolerance
Underage drivers may face more strict measures than standard per se BAC levels. Motorists under the legal drinking age often have "zero tolerance" rules that make it illegal to have any amount of alcohol in their blood. The official limit may range from zero to 0.02%, depending on your state. This makes sense, as it's prohibited for those under the age of 21 to consume alcohol. A DUI conviction can result in losing driving privileges, orders to install an ignition interlock device, or even jail if your BAC exceeds the adult legal limit.
Drugs and Per Se Laws
The BAC limits established by per se DUI laws do not address driving under the influence of drugs. However, most states have enacted per se laws about drugged driving in recent years.
Most states have a zero tolerance rule for intoxicating drugs in a person's system. These laws reference the intoxicating substance or its metabolite in your system.
As of 2023, Illinois, Montana, Nevada, Ohio, and Washington have established specific limits for the presence of marijuana. These range from 2 to 5 nanograms per milliliter of tetrahydrocannabinol (THC) in a driver's blood. Colorado recognizes a “reasonable inference" of intoxication if you have 5 nanograms per milliliter of THC in your blood. It does not matter if you use cannabis for a medical condition.
Prosecutions under per se laws in drug cases face the added challenge of establishing the presence of a type of prohibited substance in your system. Unlike alcohol, which comes in one form, drug testing and analysis can be more complicated. The fact that certain drugs remain in your system for days or even weeks after their intoxicating effects have worn off complicates matters. This is why the laws usually include the substance and what gets left over once your body metabolizes them.
DUI Conviction and Penalties
Most first-time DUI charges are misdemeanors but do carry heavy penalties. Some states prohibit plea bargains or a reduction in a DUI charge.
If found guilty of DUI, you will lose your driver's license for a while. You may apply for a special, limited license that will enable you to drive to work or to perform minor essential tasks. Still, these often require an ignition interlock device (IID) installed in your car. An IID is a Breathalyzer device that requires you to submit a breath sample. If it detects alcohol in your system, you cannot start the vehicle. A notification goes to an authority monitoring your case, and you face additional penalties.
Drunk driving charges will result in your arrest. If convicted, you will face heavy fines and license revocation at a minimum. You may have your vehicle impounded. Several states, such as Arizona, have mandatory jail time. Many states are moving toward compulsory IID installation, even for a first offense.
A DUI arrest and conviction on your record can make finding a job, going to college, or finding housing difficult.
Challenging the Results of Chemical Tests
These laws do not mean that all defendants who register a 0.08% BAC or higher face an automatic conviction in their DUI case. For example, defendants may challenge the validity of BAC test results, the machines that collect these results, and the procedures used. Various other defenses in criminal DUI cases also exist. It would be best to speak to a criminal defense attorney to explore what defenses might work for your case.
Have Questions About Per Se DUI Laws? Ask an Attorney
If arrested for a per se DUI offense, you may need legal representation, especially if you want to contest the blood or breath test results. Contact a local DUI defense attorney today to get legal advice. A DUI criminal defense attorney can evaluate your case and fight for the best resolution.