OPINION

MOSK, J.

Richard Joseph Burg, hereafter defendant, appeals from a judgment denying his petition for a writ of prohibition. He contends that Vehicle Code section 23152, subdivision (b), fails to give constitutionally adequate notice of the conduct it prohibits, and that the municipal court erred in overruling his demurrer to that effect. We conclude that section 23152, subdivision (b), is constitutional, and therefore affirm the judgment.

Defendant was arrested at 2:25 in the morning of March 27, 1982, for violation of section 23152, subdivision (a) (driving while under the influence of alcohol). A chemical test administered 50 minutes later revealed a blood-alcohol content of 0.23 percent. He was charged with violating section 23152, subdivision (b), i.e., driving a vehicle while having 0.10 percent or more, by weight, of alcohol in one's body. The complaint also alleged a prior conviction of former section 23102, subdivision (a) (driving while under the influence of alcohol).

Defendant demurred on the ground that section 23152, subdivision (b), gives constitutionally inadequate notice of the conduct proscribed. The municipal court overruled his demurrer, and defendant sought a writ of prohibition in the superior court. The petition was denied on the merits, and this appeal followed.

I. BACKGROUND

A. The Problem

The drunk driver cuts a wide swath of death, pain, grief, and untold physical and emotional injury across the roads of California and the nation. The monstrous proportions of the problem have often been lamented in graphic terms by this court and the United States Supreme Court. (See Taylor v. Superior Court (1979) 24 Cal.3d 890, 898-899 [ 157 Cal.Rptr. 693, 598 P.2d 854]) [quoting U.S. Dept. Health, Ed. Welf., 3d Special Rep. U.S. Cong. on Alcohol and Health (1978)]; South Dakota v. Neville (1983) 459 U.S. 553, 558 [74 L.Ed.2d 748, 755, 103 S.Ct. 916, 920] [describing the "tragic frequency" of the "carnage caused by drunk drivers"]; Mackey v. Montrym (1979) 443 U.S. 1, 17-18 [61 L.Ed.2d 321, 334, 99 S.Ct. 2612].) As observed in Breithaupt v. Abram (1957) 352 U.S. 432 [1 L.Ed.2d 448, 77 S.Ct. 408], "[t]he increasing slaughter on our highways, most of which should be avoidable, now reaches the astounding figures only heard of on the battlefield." ( Id., at p. 439 [1 L.Ed.2d at p. 453].) Indeed, in the years 1976 to 1980 there were many more injuries to California residents in alcohol-related traffic accidents than were suffered by the entire Union Army during the Civil War, and more were killed than in the bloodiest year of the Vietnam War. (Compare Cal. Highway Patrol, 1980 Ann. Rep., Fatal Injury Motor Vehicle Traffic Accidents, p. 2, tables 1a, 1b, 1c, 1d, and p. 58, tables 6a, 6b, with Statistical Abstract of U.S. (103d ed. 1982) p. 361, tables 598, 599.) Given this setting, our observation that "[d]runken drivers are extremely dangerous people" ( Taylor v. Superior Court, supra, 24 Cal.3d 890, 899) seems almost to understate the horrific risk posed by those who drink and drive.

B. The Legislative Response

Recognizing the effect of alcohol on drivers, state legislatures early in the century attempted to regulate such conduct. Because "both popular and legal views of the problem centered on the grossly intoxicated driver" (Ross, Deterring the Drinking Driver (1982) p. 2), the laws also reflected that conception. Thus, California's first statute on the topic read simply, "No intoxicated person shall operate or drive a motor vehicle or other vehicle upon any public highway within this state." (Italics added.) (Stats. 1913, ch. 326, § 17, p. 646.)

A more satisfactory means of defining the problem of drinking and driving emerged in the middle decades of this century, with the development of scientific measurement of blood-alcohol levels. (Ross, Deterring the Drinking Driver (1982) p. 2; Cameron, The Impact of Drinking-Driving Countermeasures: A Review and Evaluation 1979 Contemp. Drug Prob. 495, 497-498.) Research on alcohol's effect on both motor skills and judgment revealed that impairment occurred at alcohol concentrations as low as 0.05 percent (Hurst, Estimating the Effectiveness of Blood Alcohol Limits (1970) 1 Behav. Research Highway Safety 87), considerably below the point at which typical clinical symptoms of intoxication appear in most persons. (Ross, Deterring the Drinking Driver (1982) p. 2; Jones Joscelyn, Alcohol and Highway Safety 1978, op. cit. supra, at pp. 35-50.) Thus, in 1969, after a number of intervening amendments that attempted to refine definitions and specified penalties, California's "driving under the influence" statute (former § 23102) was fortified by the addition of former section 23126, which created a presumption of being under the influence if a driver had 0.10 percent or more by weight of alcohol in his blood. (Stats. 1969, ch. 231, § 1, p. 565.) By 1972, 47 states had similar statutes. (Murray Aitken, The Constitutionality of California's Under-the-Influence-of-Alcohol Presumption (1972) 45 So.Cal.L.Rev. 955, 958, fn. 8.)

Even these laws, which considerably assisted the prosecution of "driving under the influence" cases, proved inadequate in many respects. Under them, the ultimate question was defined in terms of the defendant's subjective behavior and condition: "Was the defendant under the influence at the time he drove?" Celerity and certainty of punishment were frustrated by the ambiguity of the legal criteria; no matter what his blood-alcohol level, a defendant could escape conviction merely by raising a doubt as to his intoxication. ( People v. Lachman (1972) 23 Cal.App.3d 1094, 1097 [ 100 Cal.Rptr. 710]; People v. Schrieber (1975) 45 Cal.App.3d 917, 923 [ 119 Cal.Rptr. 812]; Cameron, The Impact of Drinking-Driving Countermeasures: A Review and Evaluation (1979) Contemp. Drug Prob. 495, 510-511.)

In response to this continuing problem, in the past decade most states enacted additional legislation supplementing existing "driving under the influence" statutes and fashioned after what has been termed the "Scandinavian model." (Ross, Deterring the Drinking Driver (1982) pp. 21-70; Ross, The Scandinavian Myth: The Effectiveness of Drinking-and-Driving Legislation in Sweden and Norway (1975) 4 J. Legal Stud. 285; Snortum, Alcohol-Impaired Driving in Norway and Sweden: Another Look at "The Scandinavian Myth" (1984) 6 Law Policy 5; Snortum, Controlling the Alcohol-Impaired Driver in Scandinavia and the U.S.: Simple Deterrence and Beyond (1984) 12 J.Crim.Just. 331; Votey, Scandinavian Drinking-Driving Control: Myth or Intuition? (1982) 11 J. Legal Stud. 93.) These statutes — which are most frequently subdivisions of a general "driving and alcohol" statute — define the substantive offense not by the subjective term "driving under the influence," but instead as the act of driving with a specified blood-alcohol level. (Macdonald Wagner, Rep., Nat. Study of Preliminary Breath Test (PTB) and Illegal per se Laws (U.S. Dept. of Transp. 1981) (Executive Summary) p. xv.) Under these laws, proof of being "under the influence" is unnecessary. The statutes represent a legislative determination that public safety is endangered when a person drives a motor vehicle while having a specified percentage (typically 0.10) or more by weight of alcohol in his blood.

II. SECTION 23152, SUBDIVISION (b)

As noted, former section 23102 made it illegal to drive while under the influence of alcohol. Conviction required a showing that alcohol had "so far affected the nervous system, the brain, or muscles as to impair to an appreciable degree the ability to operate a vehicle in a manner like that of an ordinarily prudent and cautious person in full possession of his faculties." (Italics deleted.) ( Byrd v. Municipal Court (1981) 125 Cal.App.3d 1054, 1058 [ 178 Cal.Rptr. 480].) As explained above, prosecution under this section was facilitated by former section 23126, which established a presumption that a person with a blood alcohol level of 0.10 or more was under the influence of alcohol. ( People v. Schrieber, supra, 45 Cal.App.3d 917, 923.)

In an attempt to address the continuing threat to public safety posed by drinking drivers, in 1981 the Legislature retained the "driving under the influence" statute, renumbered it section 23152, subdivision (a), and added the statute at issue here, section 23152, subdivision (b), which provides: "It is unlawful for any person who has 0.10 percent or more, by weight, of alcohol in his or her blood to drive a vehicle. [¶] For purposes of this subdivision, percent, by weight, of alcohol shall be based upon grams of alcohol per 100 milliliters of blood."

At the urging of Congress, statutes of this kind have recently been enacted in 28 states and the District of Columbia. Depending on the statutory scheme, these enactments create either a new offense, or an alternative definition of "driving under the influence," or a lesser included offense within driving under the influence. (1) Our statute establishes a new and separate offense. ( Wallace v. Municipal Court (1983) 140 Cal.App.3d 100, 108 [ 189 Cal.Rptr. 886]; McKinley, Proving a Violation of Vehicle Code Section 23152 (b): Rabbit Tracks in the Snow or Russian Roulette? (1982) 5 Crim.Just.J. 223, 224; Comment, Driving with 0.10 % Blood Alcohol: Can the State Prove It? (1982) 16 U.S.F.L.Rev. 817, 817.)

(2) Contrary to assertions by amici curiae, some commentators, and one court, section 23152, subdivision (b), does not create a conclusive presumption of intoxication, nor does it "eliminate the prosecutor's burden of proof when the accused is found to have [0.10] percent, by weight, of alcohol in [his] blood." Instead, the statute defines, in precise terms, the conduct proscribed. In other states that have enacted a statute similar to section 23152, subdivision (b), the courts have drawn the same conclusion, notably the Washington Supreme Court which declared, "The statute does not presume, it defines." ( State v. Franco (1982) 96 Wn. 816 [ 639 P.2d 1320, 1323]; see also State v. Abbott (1973) 15 Or. App. 205 [ 514 P.2d 355, 357] [question is not whether defendant is intoxicated, but whether he had the specified level of alcohol in his blood]; State v. Gerdes (S.D. 1977) 252 N.W.2d 335, 335-336 [by proscribing driving with 0.10 percent blood alcohol, the legislature is "stating an offense"]; cf. People v. Dillon (1983) 34 Cal.3d 441, 472-476 [ 194 Cal.Rptr. 390, 668 P.2d 697] [Pen. Code, § 189 does not presume malice, it defines first degree felony murder as an offense in which malice is not an element].)

Although under section 23152, subdivision (b), it is no longer necessary to prove that the defendant was in fact under the influence, the People still must prove beyond a reasonable doubt that at the time he was driving his blood alcohol exceeded 0.10 percent. (3) (See fn. 10.) ( People v. Lujan, supra, 141 Cal.App.3d Supp. 15, 22 [the People must prove beyond a reasonable doubt that the defendant was driving a vehicle in any area open to the public, and his blood-alcohol level was 0.10 percent or more at the time of the alleged offense]; accord, Greaves v. State (Utah 1974) 528 P.2d 805, 807-808; Coxe v. State (Del. 1971) 281 A.2d 606, 607; State v. Gerdes, supra, 252 N.W.2d 335, 336; Van Brunt v. State (Alaska App. 1982) 646 P.2d 872, 873; cf. State v. Basinger (1976) 30 N.C. App. 45 [ 226 S.E.2d 216, 219].)

III. CONSTITUTIONAL ISSUES

A. Police Power

B. Void for Vagueness

Five of our sister states have addressed claims of unconstitutional indefiniteness with respect to analogous 0.10 percent statutes, and all have found the contentions meritless. ( Fuenning v. Superior Court (Ariz. 1983) 680 P.2d 121, 127-129; Van Brunt v. State (Alaska App. 1982) 646 P.2d 872, 873; State v. Franco, supra, (Wash. 1982) 639 P.2d 1320, 1324; Roberts v. State, supra, (Fla. 1976) 329 So.2d 296, 297; Greaves v. State, supra, (Utah 1974) 528 P.2d 805, 807-808; cf. State v. Pickering (Me. 1983) 462 A.2d 1151, 1160.) Additionally, a Court of Appeal and two superior court appellate departments have determined the precise issue adversely to defendant's view. ( People v. Lewis, supra, 148 Cal.App.3d 614, 617-619; People v. Lujan, supra, 141 Cal.App. 3d Supp. 15, 20-26; People v. Woodard (1983) 143 Cal.App.3d Supp. 1, 4 [192 Cal.Rptr. 229].) Defendant asserts, however, that we should not be persuaded by these decisions, because they fail to sufficiently analyze the issues and justify the results. (7a) We proceed to review defendant's claim that section 23152, subdivision (b), is void for vagueness.

Both article I, section 7, of the California Constitution and the Fourteenth Amendment to the United States Constitution declare that no person shall be deprived of life, liberty or property without due process of law. It has been recognized for over 80 years that due process requires inter alia some level of definiteness in criminal statutes. (Note, Due Process Requirements of Definiteness in Statutes (1948) 62 Harv.L.Rev. 77, 77, fn. 2.) (8) Today it is established that due process requires a statute to be definite enough to provide (1) a standard of conduct for those whose activities are proscribed and (2) a standard for police enforcement and for ascertainment of guilt. (9) (See fn. 15.) ( Connally v. General Const. Co. (1926) 269 U.S. 385, 391 [70 L.Ed. 322, 46 S.Ct. 126]; Lanzetta v. New Jersey (1939) 306 U.S. 451, 453 [83 L.Ed. 888, 890, 59 S.Ct. 618]; People v. Mirmirani (1981) 30 Cal.3d 375, 382 [ 178 Cal.Rptr. 792, 636 P.2d 1130], and cases cited; People v. Superior Court ( Engert) (1982) 31 Cal.3d 797, 801 [ 183 Cal.Rptr. 800, 647 P.2d 76]; Note, The Void-for-Vagueness Doctrine in the Supreme Court (1960) 109 U.Pa.L.Rev. 67-96; Note, Due Process Requirements of Definiteness in Statutes (1948) 62 Harv.L.Rev. 77 passim.) (7b) To begin with the second component, the statute could not be more precise as a standard for law enforcement. (Freund, The Use of Indefinite Terms in Statutes (1921) 30 Yale L.J. 437, 437.) It gives no discretion whatever to the police, and thus is not susceptible of arbitrary enforcement. ( Pryor v. Municipal Court (1979) 25 Cal.3d 238, 252 [ 158 Cal.Rptr. 330, 599 P.2d 636].) Indeed, the very precision of the standard assures the statute's validity in this respect. (Cf. Note, The Void-for-Vagueness Doctrine in the Supreme Court (1960) 109 U.Pa.L.Rev. 67, 90-91.)

Turning now to the "fair notice" component of the void-for-vagueness doctrine, we observe that the real thrust of defendant's argument is that the statute is in effect "void for preciseness." His complaint is not that the language of the statute is vague or ambiguous, but that it is too exact. His novel theory is that the statute fails to notify potential violators of the condition it proscribes, because it is impossible for a person to determine by means of his senses whether his blood-alcohol level is a "legal" 0.09 percent or an "illegal" 0.10 percent. The latter observation is probably true as a matter of fact, but it does not affect the constitutionality of the statute.

Defendant's theory would render the void-for-vagueness doctrine internally inconsistent: the notice requirement would compete with the need to provide precise standards for law enforcement. When, as in the present case, a statutory standard requires scientific measurement, the very factor that assures due process under the "standards" component would violate due process under the "notice" component.

It is apparently defendant's contention that due process requires notice that is subjectively verifiable, according to the terms of the statute, at the instant before the alleged violation. He claims the statute is invalid because it is impossible for ordinary persons actually to know when their blood alcohol reaches the proscribed point. No court, however, has interpreted the notice requirement so strictly; indeed, such a view would invalidate many other criminal laws, violations of which depend on an after-the-fact determination by a judge or jury as to the defendant's state of mind or the reasonableness of his behavior. (E.g., Nash v. United States (1913) 229 U.S. 373, 377 [57 L.Ed. 1232, 1235, 33 S.Ct. 780]; Note, Due Process Requirements of Definiteness in Statutes (1948) 62 Harv.L.Rev. 77, 79.)

(10) "Fair notice" requires only that a violation be described with a "'reasonable degree of certainty'" ( People v. Mirmirani, supra, 30 Cal.3d 375, 382) so that "ordinary people can understand what conduct is prohibited." ( Kolender v. Lawson, supra, 461 U.S. 352, — [75 L.Ed.2d 903, 909, 103 S.Ct. 1855, 1858].) The notice provided must be such that prosecution does not "trap the innocent" without "fair warning." ( Grayned v. City of Rockford (1972) 408 U.S. 104, 108 [33 L.Ed.2d 222, 227, 92 S.Ct. 2294].)

(7c) One who drives a vehicle after having ingested sufficient alcohol to approach or exceed the level proscribed is neither "innocent" within the meaning of Grayned, nor is he without "fair warning." His behavior is not "innocent" because one who drives with a blood-alcohol content above 0.05 percent is in jeopardy of violating section 23152, subdivision (a), i.e., driving while under the influence. (§ 23155, subd. (a)(2).) Indeed, in a number of states such a driver would be prima facie impaired well before he reached 0.10 percent. It is difficult to sympathize with an "unsuspecting" defendant who did not know if he could take a last sip without crossing the line, but who decided to do so anyway.

The very fact that he has consumed a quantity of alcohol should notify a person of ordinary intelligence that he is in jeopardy of violating the statute. (Accord, Fuenning v. Superior Court, supra, 680 P.2d 121, 129 ["it requires more than a small amount of alcohol to produce a .10% BAC [blood-alcohol content]. Those who drink a substantial amount of alcohol within a relatively short period of time are given clear warning that to avoid possible criminal behavior they must refrain from driving." (Fn. omitted.)] cf. People v. Perkins, supra, 126 Cal.App.3d Supp. 12, 21.) Although this factor alone sustains our determination that the statute provides adequate warning to potential violators, we find some further support in this regard from the existence for over 15 years of an analogous "0.10 percent" rebuttable presumption of being under the influence of alcohol pursuant to section 23155 and its predecessor, section 23126. Considering also today's heightened level of public awareness regarding the problem, we cannot believe that any person who drives after drinking would be unaware of the possibility that his blood-alcohol level might equal or exceed the statutory standard. ( Greaves v. State, supra, 528 P.2d 805, 808; LaFave Scott, Criminal Law (1972) § 11, p. 86, text and cases cited in fns. 28-29; Note, The Void-for-Vagueness Doctrine in the Supreme Court (1960) 109 U.Pa.L.Rev. 67, 87, fn. 99.) If, in the exceptional case, a person experiencing the symptoms of alcohol ingestion failed to be aware of them, the most probable reason would be depression of the brain function caused by the alcohol itself. "Fair notice," however, has not been interpreted as requiring the overcoming of such a self-induced obstacle. (Cf. Williford v. State (Alaska App. 1982) 653 P.2d 339, 342; Morgan v. Municipality of Anchorage (Alaska App. 1982) 643 P.2d 691, 692.)

(11) Furthermore, a statute "'"will be upheld if its terms may be made reasonably certain by reference to other definable sources."'" ( County of Nevada v. MacMillen (1974) 11 Cal.3d 662, 673 [ 114 Cal.Rptr. 345, 522 P.2d 1345], and cases cited.) (7d) Charts are readily available to the public that show with reasonable certainty the number of different alcoholic beverages necessary for a particular individual to reach a blood-alcohol level of 0.10 percent. For example, the 1982 California Driver's Handbook, issued by the Department of Motor Vehicles and available in English and five foreign languages free of charge to any driver, contained a blood alcohol estimation chart on the inside of its front cover, together with the admonition: "Keep this booklet in the glove compartment of your vehicle. It will help you many times." (Cal. Driver's Handbook (Cal. Dept. Motor Veh. 1982) p. 2.) The current handbook contains a significant discussion of the 0.10 percent law, and concludes with the highlighted admonition that "[t]he average size person (160 pounds) can reach a .10 BAC [blood-alcohol content] with as few as three or four average drinks (or beers) in one hour." (Cal. Driver's Handbook (Cal. Dept. Motor Veh. 1983) p. 40.) Although it is true that even with use of a chart a person may err in his estimate and thereby violate the statute, this fact does not render the statute invalid. "[T]he law is full of instances where a man's fate depends on his estimating rightly . . . some matter of degree." ( Nash v. United States, supra, 229 U.S. 373, 377 [57 L.Ed. 1232, 1235].) We are aware of none that has been declared unconstitutional for that reason.

We decline to frustrate the Legislature's clear and legitimate purpose in enacting the statute involved here. ( People v. Vis (1966) 243 Cal.App.2d 549, 555 [ 52 Cal.Rptr. 527], and cases cited; cf. Winters v. New York (1948) 333 U.S. 507, 535 [92 L.Ed. 840, 860, 68 S.Ct. 665] [dis. opin. of Frankfurter, J.].) We conclude that under both the federal and state Constitutions, section 23152, subdivision (b), provides adequate notice of the conduct proscribed, and is not void for vagueness. ( Grayned v. City of Rockford, supra, 408 U.S. 104, 108 [33 L.Ed.2d 222, 227, 92 S.Ct. 2294]; People v. Mirmirani, supra, 30 Cal.3d 375, 382.)

IV. PRIOR CONVICTIONS

The judgment is affirmed.

Bird, C.J., Kaus, J., Broussard, J., Reynoso, J., Grodin, J., and Weinstein, J., concurred.

Appellant's petition for a rehearing was denied January 19, 1984.