How much can you drink and drive?

Recently we’ve taken note of some articles and musings on the internet suggesting that there is no “safe” amount of alcohol in your body if you drink and drive. That’s complete rubbish. It is not an offence in Canadian law, nor is it unsafe to have a small amount of alcohol in your body while driving a car. What is a “safe” amount of alcohol is different from person to person.

A lawful blood-alcohol concentration in British Columbia is 49 mg of alcohol in 100 ml of blood or less. A “safe” blood-alcohol concentration is an issue of whether you are impaired or affected by the alcohol in your body in your ability to drive. The question for each person is how much can you drink and drive while neither being over the limit nor affected in your ability to drive by alcohol? What is a “safe” amount of alcohol in your body if you are driving?

When the IRP scheme was introduced, former Solicitor General Rich Coleman famously remarked that it was still okay to have a glass of wine or a beer and then drive. His comments freaked out the abstinence crowd who want you to believe that any amount of alcohol is unsafe or illegal. But even the RCMP came out to say that the IRP laws don’t require teetotalling.

Now we see members of the RCMP telling people that you can’t have anything to drink before driving. That’s just wrong and it’s incorrect legal advice. It does, however, highlight a certain point we’ve been trying to make: you simply can’t trust the Government or the police (an arm of the Government) to be correct or honest with people. We expect that you already know this because you’re reading our blog.

Now it’s time to take the tinfoil off our heads for a moment and tell you what is a safe amount of alcohol in your body if you plan to drive. You’re allowed to drink and drive. That’s not prohibited, despite the comments recently noted. But there is a limit and exceeding it can bring down a world of grief. How much can you drink and still drive?

Impaired or Affected?

There are two legal standards we deal with in BC: a) affected in your ability to drive; and b) impaired in your ability to drive. The term “affected” is used in the BC Motor Vehicle Act. It was chosen because it seems to imply something less than “impaired.” The concern was that, if the BC legislation used the word “impaired” then this would impinge on the Federal Government’s legislative authority with respect to passing criminal law.

Simply put, the people who wrote the BC legislation thought that by using “affected” they could fend off any challenge to the law concerning whether it was outside of the legislative authority of the provincial government. “Affected” was meant to imply something less than impairment and that would therefore garner much lighter consequences. At the time it was originally used, the consequence of being “affected” was a 24-hour prohibition. Now it’s an IRP which is entirely different from a simple 24-hour.

It is a criminal offence to drive while you’re ability to drive is impaired by alcohol. We’re not talking about the empties on your dashboard. The Federal Government is responsible pursuant to the constitution to make legislation concerning what is a criminal offence in Canada. (Note: in Canada we use “offence” and in the U.S. they use “offense”) If your ability to drive is impaired, to the slightest degree, by alcohol in your body and you drive or have care and control of a motor vehicle, you’re committing a crime.

But really, what’s the difference between “affected” and “impaired?” To suggest that a person is “affected” seems to suggest that the alcohol has an impact on the ability to drive. Could it be a positive impact? Interestingly, a number of studies show a decrease in the likelihood of getting into an accident at very low blood-alcohol concentrations. Did the alcohol impact the driving skills of these people in a positive way? Perhaps the only effect is that the drivers were intentionally more cautious for fear of detection and scrutiny of the police.

No, it seems to us that the only way you can be “affected” is negatively affected, i.e. “impaired.” There have been decisions from our Courts in BC that say there is no distinction with respect to whether a police officer was of the opinion that a subject was “affected” or “impaired.” So we simply use “affected” because, if there is a distinction, it’s the lower standard.

How much alcohol will make you either affected or over the limit?

It depends on you. Weight is the most important factor. Light people are affected with smaller amounts of alcohol. If you drink regularly, you may develop a tolerance to alcohol that will allow you to drink more before you are affected in your ability to drive. Similarly, eating before or while drinking can slow absorption and affect whether you’re “affected.” Experts agree that everyone is impaired when their BAC gets to 100 mg in 100 ml, but most people are affected long before that. Some people will demonstrate no impact on their ability to drive at a BAC as high as .08%.

For us, as lawyers who test breathalyzers, ourselves and other people all of the time, we make it a point not to drive if we feel any effects of alcohol. Generally speaking, we’ve noticed that for ourselves we get to this point before we reach .05%. When we drink together and breathalyzer each other the average BAC where we start to notice effects of alcohol of any sort is .04%.

For Paul, that’s 2 pints of beer over one hour. Much more than that and there is an effect on his ability to drive. Under normal circumstances, Paul is slightly affected by alcohol in his ability to drive at that point. For Kyla, more than two glasses of wine in an hour is when we observe that their ability to drive may be affected. Often it takes more than that, depending on some of the factors listed above.

At two glasses in that period of either beer or wine as the case may be, none of us are over .05% alcohol concentration in our blood, nor do we show any negative impact on our ability to drive. All of us are trained to make people perform police Standardized Field Sobriety Tests. All of us have occasionally failed the tests when we were sober and passed them after a few drinks.

How much alcohol is a “safe” amount to drink and drive?

If you weigh over 120lbs (about 55kg) you are safe in our opinion to have one standard size drink and drive right away or anytime after. You won’t be over the limit, and you probably won’t be affected in your ability to drive. For many people, two standard sized drinks is still lawful and “safe” in the sense that there may be no impact on driving skills or ability to drive.

More than 2 in a short period, such as an hour? Don’t chance it. A person of average weight and average tolerance to alcohol is likely to be over the .05% limit and possibly affected in their ability to drive. And as we said up above, exceeding this limit and the legal standard is likely to bring you a world of grief if you get behind the wheel.

You are allowed to drink and drive. Just don’t drink and drive if you’re over .05% or affected by alcohol in your ability to drive because if you do, you can expect the Government to come down on you in a most painful way.

Are there circumstances where no amount of alcohol is safe?

In BC we punish people using ASD Approved Screening Devices. These devices can malfunction, give erroneous readings and they can’t tell the operator whether the test is of alcohol from your lungs or residual alcohol from in your mouth combined with alcohol from your lungs. So the issue isn’t so much whether there is a safe amount of alcohol in your body. In our view, bearing in mind the existence and application of the IRP law, you are not safe from the BC Government if you are in BC.

For more examples of how much can you drink and drive, check out this Globe and Mail article from November 2010:
How much is too much? The Globe tests B.C.’s drunk-driving limit

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Postscript:
I’m not certain if I’ve used “affect” when I should have used “effect,” or vice versa. Please forgive any errors you locate.