I have a problem with the law against drunk driving in California.

The law specifies a legal limit of drunkenness, and provides for serious penalties and consequences for exceeding that limit. My concern is that it is very difficult to measure levels of intoxication, requiring complex chemical analysis which is not generally available to people as they assess their own driving ability.
 
The alcohol limit is a lot like a speed limit. In California, speed limits vary from 10 to 55, 65 or 70 miles per hour. The limits are posted on the roadways where they apply. It is usually easy to monitor your speed, by glancing at your speedometer. Like most people,  I rely on the speedometer to keep my driving within legal limits. If I didn't have a speedometer, it would be difficult, if not impossible to determine if I was driving faster than the law allows.
 
All laws should be written using criteria which are easy to measure, and usually, they are. For example, unlawfully loud car stereos are not judged in decibels, (hard to measure) they are measured by the distance at which they can be heard (easy to measure).
 
Bicycle headlights are not judged by their lumens (hard to measure), they are judged by the distance they are visible at night, or the distance at which they illuminate the roadway.
 
The question is, can an ordinary person be expected to conform his conduct to the law? Only if he can measure his conduct.
 
Monitoring blood alcohol levels is difficult. Holding people accountable for crossing the .08 limit is like holding them accountable for trespassing once they walk past a particular longitude. The line is invisible. It is possible to determine your longitude, but it is awfully tricky if you don't own a sextant or GPS unit.

This difficulty in determining the legality of my own actions has led to my examination of the history of secret laws.
http://en.wikipedia.org/wiki/Secret_law

Getting Tested

After lengthy discussions with some experts in the field, I decided that I needed to experience 0.08 BAC, so that I would have, at the very least, a physical reference point to judge my future blood alcohol-related decisions.

Having been completely disappointed by the margin of error on cheap blood alcohol electronics, I wrote to my local police station for assistance. I wanted to borrow one of their machines.

I received no reply.

Later, I found that just seeking this advice was an important step in avoiding a tough sentence for DUI.

"In the Criminal Law, although ignorance may not go to guilt, it can be a consideration in sentence, particularly where the law is unclear or the defendant sought advice from law enforcement or regulatory officials" (http://en.wikipedia.org/wiki/Ignorantia_juris_non_excusat)

Please continue reading about the party on page two of breathalyzer testing. It is written up in the usual Cockeyed.com Science Club manner, but I thought I should include this introduction separately, because I am serious about this flaw in the DUI law.

Here are some anticipated questions:

Q: There is a chart, which shows, for a given body weight, approximately how many drinks translate into what Blood Alcohol Content. Isn't that chart good enough to figure out if you are breaking the law?
A: I don't think so. The chart is only good for a rough estimate because there are so many variables: The type of booze you were drinking, the percentage of fat in your body, what and when you ate, and whether you are a man or a woman.  Even that chart declares that it isn't good enough. The correct information is vital to making that expensive decision to drive after drinks.  

Imagine if cars did not have speedometers, but speeding laws were still enforced with $2,000 police radar guns. It would be really difficult to tell how fast you were going, particularly (as is the case with blood alcohol levels), you had never experienced having your speed tested, nor had any real experience with what a particular speed (for example 55 mph) feels like. Perhaps, when issuing your ticket, the officer would pooh-pooh your objections with a chart, illustrating that as you drive, you should simply calculate your speed based on the distance you have traveled divided by the time you have spent traveling.
 
Q. The only reason you care about this is because you got a DUI, and now you are trying to talk your way out of it.
A. No, I didn't. I hope the fact that I haven't gotten a DUI gives this argument legitimacy. I'm not just out to save my own skin. I think this particular rule is flawed, and is continually broken because people have no good way of knowing when they have crossed the legal limit.

Q. Isn't it better to just call a cab and play it safe?
A. You don't have a choice. If you don't know what .08 feels like, you had better not drive.  You risk a night in jail and $1000 fine, and apparently the state has very little incentive to help you measure your own blood. You aren't born knowing what .08 BAC  feels like, and you don't develop a sense of what .08 BAC feels like unless you have a chance to get it measured.

Q. I like your analogies, can you think of another one?
A. Sure. Enforcing DUI rules based on blood alcohol content are like giving a blind person a ticket for crossing against the red light. How can a blind guy tell if he is breaking the law? He can't. He has to guess.