This is perhaps one of the most wide-spread myths about drinking and driving. The idea that you can have one beer per hour is based on the scientific formulas used to calculate blood alcohol levels in the majority of the population. These formulas have variables that include weight and gender, meaning that the one-beer-per-hour rule is not universally true. In fact, it almost never applies in the case of women. If you're a particularly thin male, it may also not apply to you. Finally, as soon as your average weight male pours his third drink, the rule stops applying. A forensic expert is quoted in this article as stating that a 150 pound male needs two hours to fully eliminate the alcohol in one beer. I would never rely on a rule like this to determine that I'm safe to drive.
It also depends on the concentration of alcohol in the beer, and the size of the serving. One 12 ounce beer with 5% v/v alcohol is what this idea is based on. Of course, most bars serve draught beer in larger serving sizes. Craft beers, which are increasingly popular in British Columbia, may have alcohol contents significantly higher than 5%, which negates this formula. Various wines have different alcohol concentrations, and it is almost impossible to determine the alcohol content of mixed cocktails served at popular restaurants. Often these cocktails contain two ounces of alcohol, far more than the one-drink-per-hour theory contemplates.
If you go to sleep, you'll be fine to drive once you wake up
Alcohol is eliminated at a consistent rate, regardless of whether you are awake or asleep. If the early-morning roadblocks favoured by the Vancouver Police Department teach us anything, it's that most people who wake up in the morning may not experience the symptoms of alcohol consumption but may still be over the legal limit. Most of the population eliminates alcohol at a rate of between 10 - 20 mg of alcohol per hour. More experienced drinkers tend to have a higher elimination rate, while those who drink less often eliminate more slowly.
It's not always easy to tell whether you are still drunk in the morning. A few hours of sleep does not increase your elimination rate. Mostly, it just gives you a break from the symptoms of impairment such that you feel "fine" when you wake up, even though you are not in any lawful position to drive.
In British Columbia, we have had some form of 24-Hour Prohibition from driving in place for about forty years. The 24-Hour time limit is a good indicator about what kind of timeline may be necessary to eliminate alcohol. Even after you stop drinking, it can take approximately half an hour to reach the peak blood alcohol level in normal social drinking situations. For people who consume large doses of alcohol in short time spans, it can take even longer. Some studies have shown plateauing in the blood alcohol level for as long as 90 minutes after the end of consumption. So if you're dumb enough to attempt a centurion or you otherwise drink a lot of alcohol very quickly, you may not enter the elimination phase of drinking for even longer.
The reality is that sleeping does nothing. The only way to eliminate alcohol is to allow time to pass.
If you drink lots of water, or eat a lot, you will get rid of the alcohol faster
See the above comments on how alcohol is eliminated. Drinking water will not impact your blood alcohol level or your elimination rate. There have been studies that connect the rate of alcohol absorption to the presence of food in the stomach, but this won't change how you eliminate the alcohol. Typically, alcohol can remain undigested in the stomach for two to four hours if consumed on an empty stomach, and between 4 and 6 hours if consumed with food or after a meal. That's going to have the opposite effect than what you want if you're thinking that eating will get rid of alcohol faster.
Another study linked the rate of gastric emptying and peak blood alcohol level with cigarette smoking finding that alcohol absorption will be delayed when alcohol is consumed while smoking.
All that said, whether you've been smoking or eating can have an impact if you have recently vomited, burped, regurgitated, or belched before taking a breathalyzer test. If there is alcohol remaining in your stomach, the reading you obtained in those circumstances may be unreliable. This is because of the role that mouth alcohol can play in test results.
The police can only stop you for drinking and driving if your driving is bad
As I discussed in a previous post, the police in British Columbia and Canada have a wide latitude to conduct traffic stops. There is no need for the police to see or observe anything that causes them to question your sobriety behind the wheel. The Supreme Court of Canada has determined that random sobriety checks are constitutionally valid because they serve a laudable public goal of increasing public safety on the highway.
You are entitled to refuse a breathalyzer
In many U.S. states, drivers are not required to participate in the investigation of impaired driving. Just like they are allowed to avoid roadblocks, they are also allowed to say "No" when a police officer asks for a breath test. This appears to be changing, slowly. In Canada, things are different. When a peace officer makes a lawful demand for a breath sample into a roadside breathalyzer or a breathalyzer at the police station, you are required by law to comply. The consequences of refusing to provide a sample are the same as being criminally convicted of impaired driving. You can face a criminal record, a one-year minimum driving prohibition, and a minimum $1000 fine. Subsequent convictions carry mandatory minimum jail sentences.
In British Columbia, refusing to take a roadside breathalyzer test results in the most significant roadside penalty. Even if you have no alcohol in your body whatsoever, you will receive a 90-day prohibition, $500 fine, 30-day vehicle impound, and other associated consequences under the Immediate Roadside Prohibition legislation.
The big question arises when it comes to the lawfulness of the breathalyzer demand. There is no obligation in law to comply with an invalid demand. Police must have a reasonable suspicion, objectively and subjectively, that you have alcohol in your body to demand a roadside sample. They must have reasonable grounds, objectively and subjectively, to believe you are impaired by alcohol before they can ask you to blow into a breathalyzer at the police station. My office has done an in-depth discussion of how this plays out in these three blog posts. But the short answer is that there is no right against self-incrimination when it comes to breathalyzers. The results of your roadside test can be used for the Immediate Roadside Prohibition penalty, and the results of your test at the police station can be used in your criminal case as proof of your blood alcohol level.
Do not despair, though. There are many evidentiary hurdles that have be overcome by the Crown and the police before your blood alcohol readings can be used against you in any case. For this reason, many lawyers are of the view that there are more defences available to you if you blow than if you refuse.
You can speak with a lawyer before taking a roadside breathalyzer
This is a common myth that gets a lot of people in trouble. On an almost weekly basis I deal with people who refused to blow at the roadside because they did not get to speak with a lawyer. Although the Charter of Rights and Freedoms guarantees the right to counsel upon arrest or detention, the Supreme Court of Canada has determined that there is no right to counsel before blowing into a roadside breathalyzer. The reason for this is because the results are only admissible to give the officer grounds, and that the test is supposed to be taken immediately.
Of course, the problem arises when in British Columbia these test results are used to convict someone of an administrative violation. But the Court of Appeal has determined that nonetheless, there is no right to consult a lawyer first. We are currently awaiting a decision from the Supreme Court of Canada on the issue, so that may change. But as the law stands right now there is no right to counsel before blowing into a roadside breathalyzer.
A blood test is the only way to accurately measure blood alcohol levels
Okay, this is a complex one. While breath testing for alcohol content relies on studies to determine the partition ratio, which were based on White men in the 40s, and has been subject to major criticism (I mean, like a lot of criticism) this doesn't mean that blood alcohol is better determined by blood testing. There is a reason that we are so successful in impaired driving cases where blood samples are used. The potential for human error in the blood-testing process is so significant that it is almost always impossible for the Crown to prove that the blood alcohol readings are reliable.
Some of the variables that can affect the reliability of blood testing include the anticoagulant used in the container, the integrity of the vacuum seal, the swabs used to clean the area where blood was drawn, the handling of the container itself, the length of time before the blood was tested, and the temperature at which the blood was stored. Imagine that blood is like milk. It goes bad. Blood can ferment, which results in the production of alcohol and can give falsely high readings. And forget entirely the methods used to test the blood, and all the problems that can occur with the mechanics of headspace gas chromatography.
In a perfect world, assuming no human error and immediate testing of a properly-handled blood sample, the blood readings will be more reliable. But we do not live in a perfect world, so we are left with two very imperfect methods of measuring blood alcohol level. At the end of the day, in Canada it doesn't really matter because blood alcohol levels are presumed if certain preconditions are met. There is no right to challenge the general reliability of breath or blood testing. You can only challenge the process if you can show that the proper procedure was not followed.
The police have to give you a blood test if you request one
Again, this is not true. The police can make a lawful demand for a breath sample and rely on that to secure a conviction, assuming the prerequisites are met. There is no right to request a blood test instead of a breathalyzer. Similarly, you have no right to request standardized field sobriety tests or a breathalyzer at the police station instead of a roadside breath test. The police are the ones who make the determination about what type of test you should have to take. If the demand is lawful, you're required to comply or face the consequences. There is no either/or proposition.
I hope that this information clears up some of the common misconceptions about drinking and driving law in British Columbia. If you have any other questions, or know of any other misconceptions please let me know and I'll happily address them in a subsequent post.