On August 13, 1970, the plaintiff and her three children for whom she brings suit were guest passengers in a car owned and operated by the defendant. The vehicle left the road, thereby causing each of the four personal injuries. At trial, the judge denied the defendant’s motion for a directed verdict made at the close of all the evidence (Mass. R. Civ. P. *86450 [a], 365 Mass. 814 [1974]). The jury, responding by special verdict to questions put to them (Mass. R. Civ. P. 49 [a], 365 Mass. 812 [1974]), found that the defendant was not guilty of gross negligence; they weré unable to agree whether he was guilty of ordinary negligence (although it is stipulated that there was evidence to support such a finding against him). The jury was discharged. On motion for judgment in accordance with the motion for a directed verdict (Mass. R. Civ. P. 50 [b], 365 Mass. 814 [1974]), the judge directed entry of judgment for the defendant, applying the traditional rule of law that the standard of duty toward a guest passenger, as distinguished from a passenger for hire, was that of refraining from gross negligence. Wheatley v. Peirce, 354 Mass. 573, 576 (1968). The plaintiff took her appeal to the Appeals Court and we transferred the case here. In Kolofsky v. Heath, ante, 856 (1976), we held that the legislation abolishing the Wheatley rule and introducing a standard of ordinary negligence as to guest passengers (G. L. c. 231, § 85L, inserted by St. 1971, c. 865, § 1) applied only to causes of action arising after January 1, 1972 (see c. 865, § 2). The plaintiff-appellant in the present case advances an argument not made in the Kolofsky case, namely, that the principle of Mounsey v. Ellard, 363 Mass. 693 (1973), eliminating the old distinction between licensees and invitees for purposes of actions to enforce a landlord’s duty of care, should extend also to efface the distinction between guest passengers and passengers for hire in actions to enforce an operator’s duty of care; and should, moreover, be given retroactive effect under Bouchard v. DeGagne, 368 Mass. 45 (1975). We refrain from entering on a discussion of the rfelevance, or lack of it, of the Mounsey principle to the field of motor vehicle torts, since we believe that the language of the legislation (St. 1971, c. 865, § 2) — “This act shall take effect on January the first, nineteen hundred and seventy-two and shall apply only to causes of action arising after said date” — is to be read as assuming and confirming the existence of the traditional rule of the Wheatley case and changing it only as from January 1, 1972. This excludes any possibility that might otherwise exist for bringing the Mounsey principle to bear on a case like the present where the accident antedated the January 1, 1972, deadline. Cf. Higgins v. Emerson Hosp., 367 Mass. 714, 715 (1975); Carpenter v. Suffolk Franklin Sav. Bank, ante, 314, 327 (1976); Piotti v. Commonwealth, ante, 386, 387-388 (1976).
Robert P. Sullivan for the plaintiffs.
Richard K. Donahue for the defendant.
Judgment affirmed.