The defendant, Thomas J. Shields, was stopped at a State police “sobriety checkpoint” (roadblock) at *163approximately 1:15 a.m. on September 13, 1986. After performing several field sobriety tests, Shields was arrested and charged with operating his vehicle while under the influence of intoxicating liquor in violation of G. L. c. 90, § 24 (1986 ed.).
Shields moved to suppress the evidence obtained following his stop at the roadblock, contending that it was the fruit of an unlawful seizure. In support of this motion, Shields argued that the Commonwealth must prove that no less intrusive alternative would be as effective as roadblocks in enforcing c. 90, § 24, before the roadblock seizure could be found to be constitutionally permissible and the evidence obtained at the roadblock admitted. The Commonwealth acknowledged that it must prove that the roadblock was conducted in accordance with the procedures outlined in Commonwealth v. Trumble, 396 Mass. 81 (1985), and Commonwealth v. McGeoghegan, 389 Mass. 137 (1983), but denied that it must disprove the existence of equally effective yet less intrusive alternatives to enforcing c. 90, § 24, before the evidence obtained at the roadblock could be admit-
The judge noted that resolution of the dispute was likely to be dispositive of Shields’s case, that the issue was likely to arise in similar proceedings, and that an improper determination in the trial court that the Commonwealth must disprove the existence of equally effective, less intrusive alternatives to roadblocks would result in unnecessary expenditure of judicial resources at trial. Accordingly, the judge properly reported the following two questions to the Appeals Court under Mass. R. Crim. P. 34, 378 Mass. 905 (1979): “1. Whether, as a precondition to the admission of evidence obtained as a result of a sobriety checkpoint or roadblock operated by law enforcement personnel, the Commonwealth is required to prove that there was no less intrusive alternative to the checkpoint or roadblock which would have been effective to accomplish the legitimate public safety goals of the Commonwealth. 2. Whether, assuming that the preceding question is answered in the affirmative, the standard of proof by which the Commonwealth must bear its burden is beyond reasonable doubt, by clear and convincing *164evidence or by a preponderance of the evidence.” We granted the parties’ application for direct appellate review of these questions.
The defendant grounds his argument in both the Fourth Amendment to the Constitution of the United States and art. 14 of the Declaration of Rights of the Massachusetts Constitution.1 We conclude that neither of these provisions requires the Commonwealth to prove that there are no equally effective yet less intrusive alternatives for enforcing G. L. c. 90, § 24, than roadblocks. We therefore answer question one in the negative, and need not address question two.
The stop of Shields’s motor vehicle was a seizure. Commonwealth v. Trumble, supra at 86. This seizure violates the Fourth Amendment and art. 14 only if it was unreasonable. See, e.g., INS v. Delgado, 466 U.S. 210, 215 (1984); Commonwealth v. Sheppard, 394 Mass. 381, 391 (1985). Decisions of this court and of the Supreme Court establish that there is “no ready test for determining reasonableness other than by balancing the need to search [or seize] against the invasion which the search [or seizure] entails.” Commonwealth v. Silva, 366 Mass. 402, 405 (1974), quoting Camara v. Municipal Court of the City of San Francisco., 387 U.S. 523, 536-537 (1967) (administrative search). See Trumble, supra at 86 (to determine reasonableness of seizure court balances “the public interest against ‘the individual’s right to personal security free from arbitrary interference by law officers’ ”), quoting United States v. Brignoni-Ponce, 422 U.S. 873, 878 (1975).
Because Shields was seized without a warrant, the Commonwealth bears the burden of proving that the seizure was reasonable. Commonwealth v. Antobenedetto, 366 Mass. 51, 57 (1974). To carry its burden of proving that the roadblock seizure was reasonable the Commonwealth must show, at least, that the roadblock was conducted in accordance with the guidelines established in Trumble, supra, and Commonwealth v. Mc-*165Geoghegan, 389 Mass. 137 (1983). See Commonwealth v. Amaral, 398 Mass. 98, 101 (1986). Adherence to these guidelines, the content of which need not be recited here, assures that a roadblock seizure is the result of a “plan embodying explicit, neutral limitations on the conduct of individual officers. ”Brown v. Texas, 443 U.S. 47, 51 (1979). Conducting roadblocks in accordance with such neutral criteria minimizes the risk “that the individual’s reasonable expectation of privacy [will be] ‘subject to the discretion of the official in the field. ’ ” Delaware v. Prouse, 440 U.S. 648, 655 (1979), quoting Camara, supra at 532. Adherence to the guidelines’ requirements also assures that the surprise, fear, and inconvenience to — and therefore the intrusion on — the motoring public is minimized. See McGeoghegan, supra at 143-144. In sum, leaving aside the question of less intrusive alternatives, where the Commonwealth shows that a roadblock employed to enforce c. 90, § 24, was operated in accordance with the established guidelines, the accompanying seizures, although not conducted on the basis of individualized suspicion, are reasonable under the Fourth Amendment and art. 14. Trumble, supra at 89-90.2
Shields, of course, does not leave aside the question of less intrusive alternatives. He argues that, in order for the Commonwealth to meet its burden of showing that the roadblock seizure at issue here was reasonable, it must prove that there was no *166equally effective yet less intrusive alternative to enforcing c. 90, § 24. We disagree.
Less intrusive alternative analysis traditionally has not been employed in determining the constitutional reasonableness of searches and seizures. Indeed, in one case involving a vehicle search we declined to employ less intrusive alternative analysis and observed that “[t]he fact that, in the abstract, less intrusive means might have been used does not, by itself, render the search unreasonable.” Commonwealth v. Ortiz, 376 Mass. 349, 357 (1978), citing Cady v. Dombrowski, 413 U.S. 433, 447 (1973). Accord United States v. Sharpe, 470 U.S. 675, 687 (1985) (“The question is not simply whether some other alternative was available, but whether the police acted unreasonably in failing to recognize or to pursue it”); United States v. Villamonte-Marquez, 462 U.S. 579, 591 n.5 (1983); United States v. Martinez-Fuerte, 428 U.S. 543, 556 n.12 (1976). The defendant does not address the language quoted from Ortiz, supra, nor does he indicate why the principle of that language is inapplicable in this case.
Article 14 and the Fourth Amendment proscribe only unreasonable law enforcement conduct. As such, these provisions evince a policy of accommodating the legitimate State interest in law enforcement while preventing arbitrary searches and seizures. It would be inconsistent with that policy to rule that, in order to prove that a search or seizure is lawful, the Commonwealth must prove that each of a multiplicity of proffered hypothetical courses of conduct if used would be either less effective or more intrusive. Where the defendant merely conjectures that equally effective yet less intrusive means of enforcing c. 90, § 24, exist, “[t]he [Commonwealth] is entitled in the interest of public safety to bring all available resources to bear, without having to spell out the exact efficiency coefficient of each component and of the separate effects of any particular component.” People v. Scott, 63 N.Y.2d 518, 528-529 (1984). The focus of the inquiry is on the conduct which in fact occurred. The Commonwealth’s burden is to prove that the intrusion generated by that conduct is outweighed by the need to search or seize. Commonwealth v. Silva, supra at 405.
*167We reject the defendant’s argument that the result we reach opens the door for suspicionless searches and seizures in other contexts. Police will not be allowed, for example, to cordon off “high crime areas” and search all the people on the street. Intrusions of this level, even for a limited search, require some degree of articulable individualized suspicion. Terry v. Ohio, 392 U.S. 1 (1968). Roadblock seizures for enforcing c. 90, § 24, are virtually sui generis in this regard.3 Their constitutionality is based in large measure on the lower expectation of privacy traditionally accorded to the motoring public. See, e.g., Commonwealth v. Ortiz, supra at 357-358 & n.7, and cases cited; People v. Scott, supra at 525. We do not view our decision today as eroding the protection against unreasonable searches and seizures afforded by art. 14 and the Fourth Amendment.
Rather than eroding the constitutional protection against unreasonable search and seizure, our decision is consistent with precedent. Roadblock seizures have been upheld in the absence of individualized suspicion and without a showing of no equally effective yet less intrusive alternative. United States v. Martinez-Fuerte, supra at 545, 556-557 & n.12 (1976) (permanent roadblock conducted sixty-six miles from border to detect illegal aliens; less intrusive alternative analysis rejected). See Delaware v. Prouse, supra at 663 (indicating that roadblock stops of all oncoming traffic are permissible). In the analogous context of courthouse entry searches we have approved an initial search not based on articulable individualized suspicion so long as it “was no more intrusive than necessary.” Commonwealth v. Harris, 383 Mass. 655, 657 (1981). In the case of roadblocks to enforce c. 90, § 24, compliance with the Trumble and McGeoghegan guidelines assures that the initial seizure is *168no more intrusive than necessary. We perceive nothing in the prior decisions, nor anything in the nature of art. 14 or the Fourth Amendment, which requires the Commonwealth to disprove the existence of equally effective yet less intrusive alternatives to enforcing c. 90, § 24.
Although there is some support elsewhere for the defendant’s position, the result we reach appears to be consistent with the weight of authority from other jurisdictions. Some courts which have addressed the constitutionality of roadblocks to prevent intoxicated driving have required a showing of no less intrusive yet equally effective alternatives. State v. Superior Court, 143 Ariz. 45, 48-49 (1984) (State sustaining its burden). State v. Koppel, 127 N.H. 286, 292 (1985) (State constitutional grounds). Higbie v. State, 723 S.W.2d 802, 805 (Tex. Crim. App. 1987). See State v. Muzik, 379 N.W.2d 599, 604 (Minn. Ct. App. 1985) (State must demonstrate either need for roadblock or its superiority to less intrusive alternatives). The majority of jurisdictions discussing the existence of other alternatives, however, either have rejected this requirement, People v. Bartley, 109 Ill. 2d 273, 287 (1985), cert. denied, 475 U.S. 1068 (1986), rev’g 125 Ill. App. 3d 575, 578 (1984), which had required a showing of no less intrusive yet equally effective alternative; State v. Garcia, 500 N.E.2d 158, 162-163 (Ind. 1986), cert. denied, 481 U.S. 1014 (1987), overruling State v. McLaughlin, 471 N.E.2d 1125 (Ind. Ct. App. 1984), which had required a showing of no less intrusive yet equally effective alternative; Little v. State, 300 Md. 485, 504-506 (1984); People v. Scott, supra at 528-529, or have indicated that the presence of such alternatives is merely one factor to be considered in determining the constitutional reasonableness of the roadblock seizures. State v. Jones, 483 So. 2d 433, 437-438 (Fla. 1986). State v. Deskins, 234 Kan. 529, 541 (1983).
Question one is answered in the negative. Question two therefore need not be reached. This case is remanded for proceedings consistent with this opinion.
Article 14 provides in some circumstances greater protection from searches and seizures than does the Fourth Amendment. See, e.g., Commonwealth v. Upton, 394 Mass. 363, 372-377 (1985) (stricter standard for determining probable cause under art. 14).
The question of probable cause has not been raised in this case (or in the companion case we decide today). Nor was the subject of probable cause presented or discussed in our earlier opinions concerning roadblocks. The dissent nevertheless volunteers a discussion on the question.
The basic issue is the reasonableness of the search, not the presence or absence of probable cause to believe evidence of a crime is likely to be found. In administrative searches a showing of individualized suspicion is not required because of the public interest in the inspection. See Camara, supra at 534-535. The same considerations fairly apply with respect to roadblocks conducted pursuant to established procedures in order to detect drivers operating under the influence of alcohol or other drugs. See 4 W.R. LaFave, Search and Seizure § 10.8(d), at 70-71 (1987). That probable cause need not be shown as to the driver who is stopped is implicit in what we said in Commonwealth v. Trumble, supra at 89-90, when we concluded that a search pursuant to established guidelines would be reasonable under both the Federal and State Constitutions. See also id. at 96 (Abrams, J., concurring).
The strong State interest in eliminating “[t]he carnage caused by drunk drivers,” South Dakota v. Neville, 459 U.S. 553, 558 (1983), sets roadblocks to enforce c. 90, § 24, apart from roadblocks for other purposes. Although the Supreme Court has indicated that roadblock seizures to enforce license and registration regulations do not violate the Fourth Amendment, Texas v. Brown, 460 U.S. 730, 739 (1983), it may well be, given the much lower State interest in assuring compliance with license and registration regulations, that roadblocks for that purpose are not permissible under art. 14.