George Franco appeals from a superior court jury verdict finding him guilty of driving while under the influence of intoxicating liquor (DWI). His appeal raises questions concerning the interpretation of that recently enacted law and its constitutional effect on the implied consent law. We hold the DWI statute sets out alternative methods of committing one crime, and find no constitutional violation of Franco's rights by virtue of the provisions of the implied consent law.
At 1:56 a.m., September 12, 1979, appellant Franco was driving a red Toyota on the University of Washington campus. While southbound on Stevens Way, he executed a tight left-hand turn to go northbound on Whitman Court. During the process of the turn the tires were squealing, which caused a University of Washington police officer to take notice. The officer had a "good idea” that the Toyota was exceeding the posted speed limit of 20 miles per hour, he had also observed pedestrians step out of the Toyota's way, so he accelerated to get in behind the car and followed it approximately one-half block until the car pulled over to discharge a passenger. The officer, on approaching the vehicle, informed the driver that he had been speeding, asked for his operator's license and at the time noticed a slight odor of alcohol about his person. He requested that Franco step from the car and perform the finger-to-nose test. The officer observed that Franco was swaying and that he performed the finger-to-nose test poorly. He arrested the appellant for driving while under the influence of intoxicating liquor and transported him to the police station. After being advised of his Miranda rights, appellant *819indicated he had consumed two drinks at The Broadway. He submitted to the Breathalyzer and the test revealed a 0.10 percent blood alcohol content (BAC). During a trial before a jury in the Superior Court, Franco testified on direct examination that he had consumed one gin and tonic at approximately 9 p.m. at a friend's house; a mai tai and a tequila sunrise at The Broadway between 10 p.m. and 12 midnight, and two mai tais at Lion O'Reilly's between midnight and 2 a.m. On cross-examination, he indicated he had consumed two kamikazes at Lion O'Reilly's. The appellant testified "I wouldn't call it a buzz, but I felt alcohol, but it wasn't a strong effect". Franco was convicted by the jury of driving while under the influence of intoxicants. On appeal, Franco raised various issues involving the constitutionality of the laws in question and challenged the court's manner of instructing the jury.
I
The first issue raised is whether the law sets out two distinct crimes, or simply alternative methods of committing the same crime. RCW 46.61.502 states:
Driving while under influence of intoxicating liquor or drug — What constitutes. A person is guilty of driving while under the influence of intoxicating liquor or any drug if he drives a vehicle within this state while:
(1) He has 0.10 percent or more by weight of alcohol in his blood as shown by chemical analysis of his breath, blood, or other bodily substance made under RCW 46.61.506 as now or hereafter amended; or
(2) He is under the influence of or affected by intoxicating liquor or any drug; or
(3) He is under the combined influence of or affected by intoxicating liquor and any drug.
The fact that any person charged with a violation of this section is or has been entitled to use such drug under the laws of this state shall not constitute a defense against any charge of violating this section.
(Italics ours.)
The genesis of this law apparently began when the United States Department of Transportation, in February *8201979, produced an issue paper entitled "Alcohol Countermeasures Illegal Per Se and Preliminary Breath Testing". The issue paper encouraged state legislatures to enact "illegal per se laws" establishing, as a traffic offense, the operation of a motor vehicle with a BAC equal to or in excess of a specified level, typically 0.10 percent. These statutes had been enacted in several states. Apparently as a result of the issue paper, the Washington legislature considered testimony from Dr. Ted Loomis, Ph.D., M.D., Professor of Pharmacology and Toxicology at the University of Washington. In a letter to Senator Dan Marsh, Dr. Loomis indicated, among other things, that there is an abundance of scientific support to indicate that with a BAC level of 0.10 percent, all persons are significantly affected. At that level, all persons will have lost one-quarter of their normal driving ability, some persons will have lost as much as one-half of their normal driving ability and a few people will not be able to even sit up in the driver's seat. Dr. Loomis concluded:
the amount of alcoholic beverages necessary to produce a blood alcohol level of 0.1% is considerable and is believed by most people to represent abusive and excessive acute consumption of alcohol. . . . most people who drink alcoholic beverages will recognize that the consumption of more than 8 to 9 "drinks" (that is, a half pint of whiskey, or one and one-half six packs of beer, or a quart of natural wine) in two or three hours will produce subjective effects and impaired physical performance. Yet, it is the consumption of approximately this amount of beverage that is required to produce a blood alcohol of 0.1% in the average adult.
It was against this backdrop of information the legislature amended the DWI law.
Other jurisdictions have various ways of legislating their prohibitions. Some states make driving with a BAC of 0.10 percent a separate and distinct crime.1 Other states make *821driving with that BAC a lesser included offense of driving while under the influence of intoxicants,2 and a third group of states make it an alternate method of committing the crime of driving while under the influence.3
The tests for determining whether a statute describes a single offense committable in more than one way or describes multiple offenses is set out in scholarly detail in State v. Arndt, 87 Wn.2d 374, 553 P.2d 1328 (1976). They are, briefly: (1) the title of the act, (2) a readily perceivable connection between the various acts set forth, (3) whether the acts are consistent with and not repugnant to each other and (4) whether the acts may inhere in the same transaction. All the tests for a single offense are clearly met in the present statute. In addition, the Washington legislature has not stated that one could be convicted with a BAC of 0.10 percent and concurrently, or additionally, be convicted of driving while under the influence of intoxicants; that is, driving affected in any appreciable degree, and thus, be subject to two penalties. See State v. Golladay, 78 Wn.2d 121, 470 P.2d 191 (1970) and State v. Ladely, 82 Wn.2d 172, 509 P.2d 658 (1973), for an analysis of the larceny statute which placed great weight on the fact that the subsections describing the manner of committing the crime were joined in the disjunctive by "or". Such is the language in the statute before us. We see no reason to construe the present statute in a manner inconsistent with our views on prior statutes or with the clear, concise, unambiguous language of the statute itself. We, therefore, conclude that under the statute there are three alternate ways of committing the crime entitled DWI.
*822II
Appellant contends that the trial court erred in delivering jury instructions Nos. 3 and 4. Jury instruction No. 3 is taken from RCW 46.61.502(1) and reads as follows:
A person commits the crime of driving while under the influence of intoxicating liquor when he drives a motor vehicle while:
(1) He has 0.10 percent or more by weight of alcohol in his blood as shown by chemical analysis of his breath, blood or other bodily substance; or
(2) He is under the influence of or affected by intoxicating liquor.
Jury instruction No. 4 reads:
To convict the defendant George E. Franco of driving while under the influence of intoxicating liquor, each of the following elements must be proved beyond a reasonable doubt:
(1) That on or about the 12th day of September, 1979, defendant drove a motor vehicle;
(2) That at the time the defendant either:
(a) Had 0.10 percent or more by weight of alcohol in
his blood, as shown by chemical analysis of his breath,
blood or other bodily substance; or
(b) Was under the influence of or affected by intoxicating liquor; and
(3) That the acts occurred in King County, Washington.
If you find from the evidence that elements (1) and (3) and either (2) (a) or (2)(b) have been proved beyond a reasonable doubt, then it will be your duty to return a verdict of guilty. Elements (2) (a) and (2)(b) are alternatives and only one need be proved.
On the other hand, if, after weighing all of the evidence, you have a reasonable doubt as to any of these elements, then it will be your duty to return a verdict of not guilty.
According to appellant, the jury was improperly instructed as the instructions contained impermissible presumptions or, in the alternative, the instructions set out two separate methods for committing the same crime and, as such, the jury should have returned a separate verdict as to each method.
*823Under the prior DWI statute, RCW 46.61.506, the amount of alcohol in a person's blood created certain presumptions as to whether or not a person was under the influence of intoxicants.4 Under the present statutory scheme, however, the presumptions have been abolished. Instead, the statute sets out alternate methods of committing the crime of driving while under the influence. The statute does not presume, it defines. Thus, driving with a 0.10 percent BAC is one method of committing the crime of driving while under the influence. Instruction No. 3 is, therefore, proper.
Instruction No. 4 correctly sets out the elements as alternatives which do not require unanimous verdicts as to methods. State v. Arndt, supra. Arndt holds that where a single offense is committable in more than one way, it is unnecessary to a guilty verdict that there be more than unanimity concerning guilt as to the single crime charged, provided there is substantial evidence to support each of the means charged. Only if the statute describes several separate and distinct offenses must there be a unanimous verdict as to each separate crime described. Arndt, at 377-78.
Here there was sufficient evidence at trial to support both methods charged — the quantum required is set out in State v. Green, 94 Wn.2d 216, 221, 616 P.2d 628 (1980).
the relevant question is whether, after viewing the evidence in the light most favorable to the prosecution, any rational trier of fact could have found the essential elements of the crime beyond a reasonable doubt."
(Citation omitted.) Of course, this court need not decide that it agrees with the verdict, for the credibility of the witnesses is a matter for the jury.
The appellant cites to Green for its proposition that separate jury verdicts are required. Green is inapposite here, it *824dealt with an aggravated murder, the instruction directed the jury to find the defendant guilty if convinced beyond a reasonable doubt that
defendant caused the death of Kelly Ann Emminger in the course of or in furtherance of rape in the first degree or kidnapping in the first degree.
(Italics omitted.) Green, at 231. Green determined that there was insufficient evidence to find that there was a kidnapping and thus that issue should not have been submitted to the jury. In deciding on the effect of this, the court noted that, due to the absence of a unanimous jury determination that there was a rape or kidnapping or both, it was possible that some members of the jury based their votes on the invalid kidnapping grounds. Green did not hold that in all cases of aggravated murder there must be separate jury verdicts regarding each method. That issue was not before the court.
Green cited, and carefully distinguished Arndt which is clearly controlling in this case.
Ill
Appellant next contends that in defining the crime of driving while under the influence as having a 0.10 percent BAC, RCW 46.61.502(1) is itself violative of due process for the accused cannot necessarily know when he has consumed a sufficient amount of alcohol so as to render himself in violation of the law.
At the outset, it is important to note that both parties agree that the creation of such legislation is clearly within the police power of the State. The problem arises over whether the statute is constitutionally infirm as, according to appellant, a person can be convicted without fair notice of conduct forbidden by the statute, since the only way to know the weight of alcohol in one's blood is through chemical tests. This argument has been rejected by other jurisdictions which have similar DWI legislation on the basis that it is reasonable to assume that the physical and mental condition of a driver with such a high level of *825blood alcohol is impaired. See, e.g., Roberts v. State, 329 So. 2d 296 (Fla. 1976); Greaves v. State, 528 P.2d 805 (Utah 1974). In addition charts are available through various sources, including the state liquor board, showing the number of drinks necessary to produce the reading. Thus, although one can legally drink and drive, State v. Hansen, 15 Wn. App. 95, 546 P.2d 1242 (1976), our DWI law makes it perfectly clear that the two activities cannot be mixed to the extent that the drinking affects the driving, or the driver has a 0.10 percent of alcohol in his blood. No further specificity is required if the statute gives fair warning of prohibited conduct. See In re Powell, 92 Wn.2d 882, 602 P.2d 711 (1979).
IV
The contention that RCW 46.20.308, the "Implied Consent Law", is violative of the Fifth Amendment privilege against self-incrimination is based on the previously discussed statute where, allegedly, a breath sample taken from the DWI suspect has now been rendered testimonial in nature. As such, the accused must have the right to knowingly, intelligently and voluntarily refuse to take the Breathalyzer test without fear of having his license automatically revoked for 6 months.
Under subsection (1) of RCW 46.20.308, all those suspected of driving while under the influence of intoxicating liquor have impliedly consented to the taking of blood or breath samples to determine alcohol content of their blood. The implied consent law creates a statutory right to withdraw this consent and refuse the test, but such refusal results in a 6-month license revocation.
RCW 46.20.308 has withstood the challenge that it violated the Fifth Amendment privilege against compelled self-incrimination. See State v. Moore, 79 Wn.2d 51, 483 P.2d 630 (1971). In Moore, this court ruled that the implied consent law was not violative of either the Fifth Amendment or article 1, section 9 of the Washington State Constitution. We disposed of the federal constitutional *826challenge on the basis of Schmerber v. California, 384 U.S. 757, 16 L. Ed. 2d 908, 86 S. Ct. 1826 (1966), wherein the United States Supreme Court held that the federally guaranteed privilege against self-incrimination extended only to testimonial or communicative evidence. The court ruled that the Fifth Amendment is not violated when a suspect is compelled to permit withdrawal of his blood so as to analyze the alcohol content, even though the blood alcohol content is evidence which may be used against the suspect because "Petitioner's testimonial capacities were in no way implicated; indeed, his participation, except as a donor, was irrelevant to the results of the test, which depend on chemical analysis and on that alone". Schmerber, at 765. In Moore, the state constitutional challenge was rejected, the court holding that the definition and interpretation should be the same as that which had been afforded the federal provision.
Notwithstanding Moore, Franco renews a challenge to the constitutionality of the implied consent law on the grounds that (a) the Breathalyzer report has been rendered testimonial in nature through the passage of RCW 46.61-.502; and (b) under our state constitution, it is violative of self-incrimination as our provision is less narrowly defined than its federal counterpart.
A
Effect of the New DWI Law on the Implied Consent Law
When Moore was decided, the results of the Breathalyzer test merely gave rise to a presumption of intoxication. See former RCW 46.61.506. The Breathalyzer was evidence to be considered with other competent evidence to determine whether a defendant was under the influence of intoxicants. The blood alcohol content merely created a rebuttable presumption which the trier of fact considered in the context of other evidence.
Under the present RCW 46.61.502, however, the presence of a BAC of 0.10 percent, as shown by the Breathalyzer *827reading, is not a presumption, conclusive or otherwise, it is an alternate means of committing the crime of driving while under the influence.
Franco contends that this change in status renders the Breathalyzer testimonial in nature in that proof of the Breathalyzer reading constitutes the crime of driving while under the influence, as samples from one's breath may constitute an admission. In support, appellant relies on two recent decisions from the Washington Court of Appeals. See State v. Moreno, 21 Wn. App. 430, 585 P.2d 481 (1978); State v. Dennis, 16 Wn. App. 417, 558 P.2d 297 (1976). Both Moreno and Dennis involved prosecutions for the possession of a controlled substance. In each, the defendant, while his movements were restrained by an officer who had probable cause to believe he possessed drugs, produced the cocaine in response to a request and not a valid search warrant. No prior Miranda warnings were given. On appeal, each case was reversed and remanded for a new trial.
A review of these cases convinces us that they do not purport to change any existing case law. While we might not adopt the court's language that the production of the cocaine was "testimonial in nature", Dennis, at page 422, because the acts of producing the drug supplied the incriminating ingredient of guilty knowledge necessary to prove a case; we note that the Moreno and Dennis courts were careful to distinguish the Schmerber line of cases where the defendant was simply a "'source of "real or physical evidence". Dennis, at 422. See Moreno, at 433. It has been consistently held that compulsion which makes an accused the source of real or physical evidence does not violate the privilege. It is only violated when the accused is compelled to make a testimonial communication that is incriminating. As stated in Fisher v. United States, 425 U.S. 391, 408, 48 L. Ed. 2d 39, 96 S. Ct. 1569 (1976), we have accordingly declined to extend the protection of the privilege to the giving of blood samples (Schmerber); to the giving of handwriting exemplars (Gilbert v. California, 388 U.S. 263, 18 L. Ed. 2d 1178, 87 S. Ct. 1951 (1967)); voice *828exemplars (United States v. Wade, 388 U.S. 218, 18 L. Ed. 2d 1149, 87 S. Ct. 1926 (1967)); or the donning of a blouse worn by the perpetrator (Holt v. United States, 218 U.S. 245, 54 L. Ed. 1021, 31 S. Ct. 2 (1910)). See also State v. West, 70 Wn.2d 751, 424 P.2d 1014 (1967); State v. Craig, 67 Wn.2d 77, 406 P.2d 599 (1965).
Franco contends that because of the change of the law where 0.10 percent is a method of committing the crime of driving while under the influence, he is no longer the source of real or physical evidence, but is in fact forced to testify by giving his breath sample. He indicates there is now no application or consideration of extraneous facts or circumstances, such as comparison or identification, in order to prove guilt. His analysis is not persuasive. The breath sample must be analyzed, the machine must be proved to be in proper working order beyond a reasonable doubt by the State, the officer who gives the test must be certified and must be proved to be competent at trial. The ampules must be proved beyond a reasonable doubt at trial to have been properly tested and the State always has the burden of proving beyond a reasonable doubt to the jury that the 0.10 percent reading was a correct one. The defense has the same opportunity to attack that reading as they always have had under the prior presumptions. The defense is entitled to an expert witness instruction which was offered in this case by Franco and refused by the court, in error.5 Additional expert testimony, while available to the defendant, is not the only method of impeaching the reading on the Breathalyzer. The State's expert testimony *829may be controverted by the defendant testifying about the number of drinks he consumed and the effects of the alcohol upon him, he may call lay witnesses to testify as to those same factors, he may argue that the machine must be in error because of the slight effect the alcohol had upon him. It is simply not the case that the giving of the breath sample proves the crime.
B
Independent State Grounds
Defendant also challenges the constitutionality of the implied consent law on the basis that it is violative of article 1, section 9 of the Washington State Constitution.
Article 1, section 9 reads: "No person shall be compelled in any criminal case to give evidence against himself ..." Defendant contends that this court should interpret our constitutional provision as being more protective than the fifth amendment to the United States Constitution, because our provision protects a person from giving "evidence" against one's own self whereas the federal provision merely prohibits compelling "testimony".
Certainly, this court is free to give a provision of our constitution an interpretation more protective of individual rights than the interpretation given a similar provision of the federal constitution and we have recently done so. State v. Fain, 94 Wn.2d 387, 617 P.2d 720 (1980); Federated Publications, Inc. v. Kurtz, 94 Wn.2d 51, 615 P.2d 440 (1980); Northend Cinema, Inc. v. Seattle, 90 Wn.2d 709, 714, 585 P.2d 1153, 1 A.L.R.4th 1284 (1978). However, in State v. Moore, 79 Wn.2d 51, 483 P.2d 630 (1971), this argument was presented and we chose not to interpret our constitutional provision differently. We decline to overrule Moore, which is stare decisis on this issue.
In view of our holding that the DWI statute sets out alternate methods of committing one crime, and that none of the appellant's constitutional rights have been violated, we affirm the trial court.
Rosellini, Stafford, Dolliver, Hicks, Williams, and Dore, JJ., concur.
See Fla. Stat. Ann. § 316.193 (West); Utah Code Ann. § 41-6-44.2.
See N.C. Gen. Stat. § 20-138.
See N.Y. Veh. & Traf. Law § 1192 (McKinney); Or. Rev. Stat. § 487.540; and S.D. Compiled Laws Ann. § 32-23-1, which are identical to the Washington provision. See also Del. Code tit. 21, § 4177; Neb. Rev. Stat. § 39-669.07; Vt. Stat. Ann. tit. 23, § 1201, which are similar to the Washington provision.
RCW 46.61.506 set out that if a person had a 0.05 percent or less BAC he or she was presumed not to be under the influence; if the BAC was between 0.05 and 0.10 percent, it was merely evidence of intoxication; and if the BAC was 0.10 percent or greater, the person was presumed to be under the influence.
defendant's proposed instruction No. 8 reads:
"A witness who has special training, education or experience in a particular science, profession or calling, may be allowed to express an opinion in addition to giving testimony as to facts. You are not bound, however, by such an opinion. In determining the credibility and weight to be given such opinion evidence, you may consider, among other things, the education, training, experience, knowledge and ability of that witness, the reasons given for the opinion, the sources of the witness' information, together with the factors already given you for evaluating the testimony of any other witness." (No exception was taken and this issue was not raised on appeal.)