California Vehicle Code 23152b VC - Driving with Excessive BAC

California drunk driving law provides for two DUI offenses: (1) Vehicle Code 23152a VC, driving under the influence of alcohol and/or drugs, and (2) Vehicle Code 23152b, driving a vehicle with a blood alcohol content of .08 or higher. The Vehicle Code 23152b statute reads:

"It is unlawful for any person who has a .08 percent or more, by weight, of alcohol in his or her blood to drive a vehicle….percent, by weight, of alcohol in a person's blood is based upon grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath."

In theory, someone could be guilty of either of these DUI charges without being guilty of the other. For example, someone might be under the influence even with a .06 BAC. And someone with a .09 BAC may not yet be under the influence. It depends on the person's tolerance level to alcohol, which varies among individuals.

If the breath or blood test reads above .08, is there any defense to the Vehicle Code 23152b DUI charge?

Often times there is. First of all, an inherent range of error always exists with regard to both the DUI blood and breath alcohol tests. Second, there may be substantially erroneous readings because of faulty or mis-calibrated equipment, improper administration of the tests by the police, and medical or dental issues with regard to the subject taking the test.

Finally, because alcohol takes a period of time to absorb into the bloodstream, a person's BAC is often times lower when he/she was driving than it was later when he/she subsequently took the test-and it is the BAC at time of driving, not the time of the test, that counts for Vehicle Code 23152b purposes.

Suffice it to say that many people are able to escape DUI conviction in spite of blood or breath tests indicating a BAC above the limit. Experienced DUI defense attorneys can spot issues that cast doubt on the accuracy of the tests, often times leading to reduced or dismissed charges.

Why does Vehicle Code 23152b establish the legal limit at 08?

Everyone in the DUI industry agrees that different individuals become impaired at different blood alcohol levels. Toxicologists disagree as to the level at which all people become under the influence. Some toxicologists believe that all people in the population reach impairment levels by .08. Others believe that number is .10 or .12.

But California DUI law must establish an arbitrary BAC threshold beyond which it is illegal to drive, regardless of individual variations in tolerance and sensitivity to alcohol. In many ways, this is more of a political than a scientific decision. Some groups, such as MADD, advocate making the legal limit even lower. Vehicle Code 23152b establishes the .08 rule as a compromise position.

Jury Instruction on Vehicle Code 23152b:

Below is an abbreviated version of the California Judicial Council's jury instruction defining Vehicle Code 23152b, the DUI charge for Driving with Excessive BAC:

The defendant is charged with driving with a blood alcohol level of 0.08 percent or more. To prove that the defendant is guilty of this crime, the People must prove that:

1. The defendant drove a vehicle;

AND

2. When he drove, the defendant's blood alcohol level was 0.08 percent or more by weight.

If the People have proved beyond a reasonable doubt that a sample of the defendant's blood, breath or urine was taken within three hours of the defendant's alleged driving and that a chemical analysis of the sample showed a blood alcohol level of 0.08 percent or more, you may, but are not required to, conclude that the defendant's blood alcohol level was 0.08 percent or more at the time of the alleged offense.

BENCH NOTES

Partition Ratio

In 1990, the Legislature amended Vehicle Code section 23152(b) to state that the "percent, by weight, of alcohol in a person's blood is based upon grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath." Following this amendment, the Supreme Court held that evidence of variability of breath-alcohol partition ratios was not relevant and properly excluded. (People v. Bransford (1994) 8 Cal.4th 885, 890-893 [35 Cal.Rptr.2d 613, 884 P.2d 70].) However, evidence of variability in urine-alcohol partition ratios is admissible. (People v. Acevedo (2001) 93 Cal.App.4th 757, 765 [113 Cal.Rptr.2d 437].)