Happy New Year! And know thy limit
The best advice to give about drinking and driving is simple: Don't.
But many of us aren't quite up to taking the best advice. Good advice will have to do,
For those of us who are less than perfect advice-takers, Getting There offers the following counsel based on decades of experience:
Know thy limit, and enforce it strictly upon thyself.
Every driver who is not a teetotaler, for whom it is even a remote possibility that a drink could be consumed before driving, needs to have a solid idea of what effect alcohol has on one's blood-alcohol content.
Then, you need a wide buffer between that level and .07 -- the actual legal limit in Maryland. (It might be .08 in other places, but blow an .07 in Maryland and you'll be arrested for driving while impaired.) At the very least that means staying well under .05 -- the legal limit in many European countries. Besides the safety factor, there are jurisdictions where you can be arrested for being impaired if you are even close to .07. You might get off in court, but just getting arrested can be a costly ordeal.
A good way to determine your limit is to go to one of the web sites that offers a blood-alcohol calculator -- before the drinking starts -- and fill in the variables that apply to you. I like the web site known as "The Original BAC Calculator."
Fill in your weight (be ruthlessly honest) and gender and pick your favorite poison -- beer, wine, martinis, etc. Then experiment with different combinations of numbers of drinks and time spent in imbibing. Click on the button and it will give you a reasonably good estimate of what your BAC would be. (There is one gaping flaw: It doesn't account for Maryland's .07 law and will tell you a reading between .07 and .08 is "possibly impaired." There's nothing possible about it.)
One thing that becomes very clear is that BAC readings are not fair. When it comes to alcohol, chemistry discriminates on the basis of sex and weight. If you are a small woman, it might come as a shock how few drinks it takes to brush the limit. Two beers for 195-lb. me in an hour? Not impaired, it says. But for a 110-pound woman, that would be scraping the legal limit at .066. That's far too close to handcuffs for comfort.
And when it comes to martinis, let's just say that even one is too many unless you're a big, big guy.
There are all kinds of caveats attached to the use of such web sites. Reading the legal disclaimers is a good idea. One big variable is the level of food consumption. Another is how one has paced the drinking. And don't get that limit locked into your head: If you lose 40 pounds, you won't be able to drink what you did in the Fat Old Days.
The Original BAC web site generally advises that one is "possibly impaired" at .04 percent or above. That seems to be a prudent guideline.
Of course, knowing your approximate limit is no good if you start giving yourself permission to have "just one more." If you don't have good brakes on your drinking, it's best not to start up the engine. And no super-sizing. A beer means 12 ounces, domestic, not 750 milliliters of Belgian ale.
Rather than obsessing over chemistry, people who just want to enjoy themselves this New Year's Eve might want to consider several delightful alternatives to driving such as taxis, hotels, crashing with friends, mass transit and celebrating at home.
Happy New Year from Getting There.
Some sample readings from Original BAC
(Don't take this as legal advice but as an illustration of the range of variation)
200-lb man, 3 beers or 3 wines, two hours = .027 (not impaired)
120-lb woman, 3 beers or 3 wines, two hours = .08 (impaired)
160-lb. man, 2 margaritas, 1 hour = .051 (possibly impaired)
160-lb. woman, 2 margaritas, 1 hour = .059 (possibly impaired)
180-lb man, 3 rum & cokes, 2 hours = .034 (not impaired)
130-lb. woman, 3 rum & cokes, 2 hours = .071 (impaired under Maryland law)
110-lb. woman, 1 martini, 1 hour = .093 (impaired)
200-lb. man, 1 martini, 1 hour = .037 (not impaired)